Eagle Nest Updates
Due to unknown circumstances, the second of the two eaglets born this year expired early April 1st. The loss of two eaglets (3/27 & 4/1) is a rare experience at this nest; complete nest failures are not regular occurrences. The 2ndhatchling, born Tues. March 28th, appeared to be sound; moving within the nest bowl and taking food from the parents within one day of hatching. Food was continuously provided over the next three days, and both adults took turns brooding the chick.
Biologists do not know what affected the recently hatched chicks, but possibilities include weather or disease. Weather-related factors such as heavy rainfall during the nesting period can influence the nesting success of birds including raptors. Studies show that inclement weather can drive avian parents to increase their energy outputs and time hunting. Heavy, consistent rainfall may have factored into the male's time away from the nest due to increases in time hunting food and the female’s need to mantle the eaglet to maintain optimal body temperatures. While such weather is not atypical for birds, these components along with any present biological challenges may lead to nest failure (McDonald et al. 2004). On Friday, March 31st, the amount of rain was significant, resulting in 0.8 inches of rain!
Microbes can be components of nests, egg laying, and hatching events. The last blog post (March 16, 2017) began a discussion of possible biological reasons for the death of the first hatchling. Research in trans-shell microbes (Cook et al. 2003) indicates that the probability of infections is high. They have shown that incubation temperatures, timing, green nesting material, and weather conditions play a role in limiting infections across the shell and inside eggs. We may never know if an infection impacted our eggs, but this is another factor in the nesting success equation.
Questions remain about the possibility of a second clutch. According to biologists at NCTC, the possibility of a second clutch is low. If they attempt another clutch, timing, weather, and food matches may pose new challenges for the pair. The amount of energy, stored fat is required to lay new eggs, and impending hot weather are major issues. Bald eagles lay and hatch before the steady summer weather arrives since they can only obtain moisture from the food they consume.
The NCTC EagleCam offers us a unique perspective: a ‘sneak peek” into the living room of an apex predator during a crucial time in its life cycle. Although this nesting season may not continue as expected and action in the nest may decline, we plan to keep the EagleCam up and running until mid-June or early July keeping an eye out for the adults who occasionally return to the nest.
We thank everyone who watch the live feed, reads the updates and corresponds with our team. We also send a special note of thanks to Terri Bayles, Debi Chiappini, Deb Stecyk, and Doreen Wermer who were integral to our 2016 research initiative to quantify prey deliveries to the nest. They along with so many others are essential to our mission and help us to maintain a watchful eye on the health and progress of this incredible species.
Thanks also to Outdoor Channel, the Friends of the NCTC, Hancock Wildlife Foundation, FWS eagle biologist Craig Koppie, NCTC staff, Lois Johnson-Mead, Clayton McBride, Rob Ball, and all of the long time followers of the cam.
Hatch day has finally arrived! The pair laid two eggs in late February, however this year, the hatch results were 50% successful. On March 25, 2017, first of two eggs began to show signs of pipping. A viable chick was expected based on the movements observed, and soft sounds heard. Due to circumstances unknown to us, the adults did not begin feeding the new chick. Over the next days (March 25-26), no feeding was observed despite a fish deliveries to the nest. The adults were observed feeding themselves but not the new hatchling.
On March 26th, no further evidence of the first hatchling was seen. Therefore, it is safe to assume based on a lack of feeding and no visual parenting behavior that the first chick did not survive. The parents continued to incubate the remaining egg. On the evening of March 27th, we did observe the 2nd egg moving, and the female was seen gazing down into the nest bowl, indicating that a second hatch was in process. When the pair switched incubation roles that morning, a small pip in the shell was evident! We are fortunate to report that the second hatch was successful and feeding began soon after final hatch March 28, 2017.
The process of pipping occurs when a hatching bird begins to emerge from inside the egg. The egg tooth starts an internal pip with breaking the membrane covering the chick. The shell is porous, allowing for air exchange, and the chick begins breaking inside the egg. Next, the external pip begins. Through internal movement, a special pipping muscle, and breaking the shell chip by chip, the emerging chick creates a larger window in the shell (Brooks & Garrett, 1970). According to raptor biologists at the Raptor Resource Project, it can take a hatchling between 24-48 hours to go from pip to hatch!
We will never know why the first chick did not survive. But a newly emerging chick goes through several significant changes before and during the hatch. Before it hatches, it needs to absorb the egg yolk inside for energy to push and pick at the egg shell. It has to start breathing inside the egg, and immediately after emerging, it has to inflate its lungs sufficiently enough to breathe on its own. With so many variables in the birthing equation, we can see how post-hatch chick survival is a significant feat and a marvel to observe.
On Monday, March 13, the eagle pair experienced a significant snowstorm for the first time during this nesting season! The storm continued into the next morning completely immersing the female in snow. She incubated the eggs throughout the night until the male returned to begin incubating the eggs.
One might wonder how an eagle keeps itself and the eggs warm when heavy snow occurs. Bald eagles have unique body features and have also been shown to alter their behavior to modulate heat as temperatures decline (Stalmaster & Gessaman, 1984). Specifically, they retain body heat and minimize heat loss by a) sedentary behavior to slow metabolism, b) slowing blood flow away from the skin to the digestive system, and by having a body covered with over 7,000 feathers. To keep the eggs warm, the brood patch, a featherless area on the chest, is placed against the eggs to keep them at an optimal temperature (99oF), with occasional egg rolls to evenly distribute heat throughout the egg.
While most birds nest during the spring season, this time of the year is optimal for raptors in response to specific environmental cues such as photoperiods and food availability. Apex predators and their offspring need a significant amount of protein for energy and growth, which fish provides. So, egg incubation occurs midwinter, just before fish spawning cycles begin. Once air and water temperatures increase, fish move back to spawning grounds to lay eggs, and these areas are near the foraging regions of the nest.
If you follow the behavior of anglers, one of the first fish caught in the Potomac River each spring are carp. Interestingly, our survey of the 2016 nest revealed the eagle adults also sourced this fish mid to late March, and were immediately fed to the eaglets after hatching!
The success of the nesting pair seems possible despite the weather because this period aligns with the breeding patterns and distribution shifts of their preferred food source, and the animals possess a unique set of physiological characteristics. In essence, the breeding strategy is food related; that is as new food emerges within the habitat, the eagle adults are ensuring that an abundant food supply is available for the rapidly growing eaglets.
It’s been two weeks since two eggs were laid at the NCTC nest on Feb. 17th & Feb. 20th. The adults continue to trade incubation sessions throughout the day with the female typically taking the night shift. Once awake, she calls out to the male who returns the call or returns to the nest. As the male focuses on the eggs, turns them, and then settles in to warm the eggs, the female flies away to hunt for food.
During the first week of March, an unusual occurrence happened midday: an intruder came close to the nest. A dark, spotted, large bird was observed descending onto the nest as the male was incubating. The adult immediately flew up to defend the nest and the eggs, scaring off the intruder. This could have been a juvenile eagle as one was seen several times during November as nest building was in initial phases. Raptor researchers report that fledged juveniles rarely return to a nest but it is possible to observe juveniles in the vicinity of a nest, possibly investigating the nest for food.
Nest maintenance continues as the male generally bring large sticks to the nest and occasionally has delivered a small meal to the nest. Mild temperatures and low precipitation occurrences have shaped the early nesting season, but wind speeds up to 50 mph on several days are a concern for a nest that is approximately 12 years old. As the winter season winds to an end, variance in daily weather conditions is to be expected. We can expect spring weather patterns to drive the nesting birds to fine-tune their behavior so they can consistently keep the egg warm, rotated, protected, and alive.
Two asynchronous eggs were laid! The first delivery occurred on February 17, 2017, and the second was delivered early morning February 20, 2017. The male and female will now share the task of incubating the eggs, trading between remaining in the nest to protect and keep the eggs warm while the other hunts and forages. We can expect up to three eggs, with the first hatch scheduled to occur on or around March 24th. The second or third hatchings will occur in order of delivery, resulting in a nest of eaglets at different maturity levels.
Several factors are known to drive avian reproduction such as hormonal triggers, temperature, food availability, and most importantly, the photoperiod (changes in day length). In 2016, the female laid its first egg on Feb. 9th when the daylight hours were recorded at 10 hours and 30 minutes, according to the U.S. Naval Observatory. The daylight hours for the February 17, 2017 delivery were almost 11 hours (10 hours and 58 minutes)! Interestingly, the eagle’s 2017 deliveries occurred 2-6 days and 6-8 days later than the 2015 and 2016 dates.
We will continue to observe the adult pair working on the nest, exhibiting bonding behaviors, and assuming the vital role of incubation for the next 35 -38 days.
In anticipation of a delivery, the bald eagle pair continues to bring sticks and grass to the nest shoring up the edges and rearranging the nest bowl center. Mating was observed several times in late November, and expectations are that the female will lay within the next week. Predicting the date of an egg delivery can be challenging, and certain factors play a role in shifting dates by one or two weeks.
American bald eagles breed during the winter or early spring when temperatures range from 25 to 45 oF (-4 to 6 oC).Temperature patterns have fluctuated in our region. In January 2017 alone, temperatures readings above 50 oF (10 oC) were recorded for 10 days. Yet bald eagle experts in Alaska believe that food availability and habitat quality drive breeding behavior (mating, nest building, etc.) more than temperature shifts (Hansen, 1987). However, extreme weather and temperatures (heavy snows or rains; below-average temperatures) can make food foraging challenging, leading bald eagles to advance or postpone egg-laying.
Fortunately, the eagles at NCTC harvest excellent food sources from the Potomac River, and this river has a man-made dam just over 1 mile from the nest site. Predicting the exact day of egg delivery may be challenging but the habitat factors within the region are supporting the annual nest success of this raptor pair and keeping those dates fairly consistent from year to year.
The eaglets have returned to the nest! After last week’s turbulent weather events resulted in fledging for both juveniles and caused two semi-controlled descents due to wind gusts, our NCTC biologists determined that both birds had left the nest bowl area. The smaller eaglet was seen in the tree at a lower level, until it flew away to return the next day, June 9th. Although the nest was empty, the adult female visited following the fledging, and once the juvenile returned the next day, a fish delivery occurred. Strong vocalizing by the eaglet preceded its rapid consumption of the prey delivery.
After a 3-day departure, the older juvenile returned to the nest on June 11th, marking an important developmental step for the eaglets. Nest success for raptors is estimated as the proportion of raptor breeding pairs that were observed to raise young to the age of fledging (Steenhof and Newton, 2007). The long nesting cycle and the parenting behaviors of the bald eagle resulted in the desired outcomes for the species (self-feeding and fledging).
Nest proximity to food sources and availability are the primary drivers for success, and have been shown to also drive egg-laying rates in different latitudes. This pair foraged successfully throughout the nesting period, only dropping the rate of prey deliveries closer to the 10-13 week of age range. As noted in previous posts, lack of moisture coupled with high temperatures may have driven fledging sooner than expected, but in the case of this nest, windy days moved the eaglets to test their newly developing wing skills. Since the fledging period has occurred, we will see how long before the eaglets move to new permanent locations and no longer frequent this nest.
As noted in the recent blog post, we are simply observers of nature using webcam technology. Human interest in observing nature without disturbing it can be traced back to our days as hunter-gatherers where we constructed observation blinds. From then to now, we have been offered a rare glimpse of their private moments, (mating) births, (feeding) deaths, and other events but how far we involve ourselves into their lives warrants careful consideration and action.
The Raptor Research Project offers an interesting point of view in an article by wildlife biologist, Julie Lamb. Follow this link: http://daily.jstor.org/wildlife-cams/.
Diets choices within the nest at NCTC have been fairly consistent with little variation in type. Fish were the primary food selections brought to the nest, often by the male adult. Occasionally, the adults feed the young, but typically at this stage of development an adult will consume part of the prey, then either leave the nest or move away, allowing the young to access the food. The older eaglet quickly descends on the prey, followed by the younger sibling. One variation in the fish prey deliveries last week was a box turtle brought to the nest and quickly devoured. Independent feeding by both eaglets is an important skill to develop, and this pair seem right on track. Eagles breed in the winter and hatch their young just prior to the spring fish runs, ensuring an abundance of food will be available. Prey deliveries provide protein and the only source of moisture the eaglets can obtain. Normal declines in food foraging rates can lead to dehydration for the young if sudden changes in weather conditions (heat or humidity) occur. This has been known to drive fledging from the nest.
Perching in the nest involves standing on a structure, such as the nest edge or a branch, and peering down to scan for potential prey and other movement. Interest by the eaglets in what was occurring near the nest edge was previously observed. When the adults roosted on nearby branches, the young often laid down nearby at the very edge of the nest, giving them a new view below the nest. As standing for longer periods became the norm, the older eaglet replaced laying at the edge with standing and peering over the edge. The younger eaglet soon followed this behavior, and now both birds are routinely observed perched side by side at the nest edge.
Wing displays have become much more frequent and vigorous, important in muscle development needed for flight. Primary displays include wing extensions, hopping, flapping, and preening. During week 10, we observed an impressive display by the older eaglet, who stretched out both wings while standing in the nest for approximately 2 minutes! Dark, flight feather development is occurring in the younger eaglet whose feathers show fewer patches of grey & white feathers than before. Throughout week 11, the eaglets took turns flapping and practicing mini flights within the nest bowl. So on March 26th, a perfectly timed event occurred: the older eaglet flew to a nearby tree stump and perched as the younger sibling watched. Branching had occurred for one of the offspring. Branching involves flying to nearby branches in the sycamore tree and exploring the surroundings. During branching, the young will continue to stay in the nest and tree, in order to be fed by the adults at this stage. The next steps should be for both young birds to begin branching so that fledging, or first flight, which typically occurs during 12 weeks of age, can begin.
Week 9 of the nesting period has been eventful for the NCTC eagles that routinely display pre-fledgling behaviors and have begun feeding themselves. Nestlings at this stage of development will practice hopping, walking, and flapping of wings. On several windy days last week, the eaglets spread their wings while balancing at the edge of the nest and gazing above and below their area. At approximately 10-14 weeks of age, the bald eagle typically show signs of branching which entails opening their wings and hopping from the nest to nearby branches. These actions are expected in pre-fledging eaglets!
Next week marks marking an important period of transition, as the eaglets will be 10 weeks old. Over the course of the next four weeks, we should witness the offspring’s movement from the nest bowl to the branches. The older offspring has been very daring, perching at the nest’s edge, while the younger eaglet, still growing its pin feathers and stretching its wings, has been more sedentary.
Changes in height, body size, and feeding behavior are evident in the young resulting in eaglets almost as tall as their parents. Feathers continue to transform from natal to distinguishing brown juvenile feathers appearing on the face, body, wings, and tail of the young. Feeding habits in the nest have shifted along with subtle changes in adult behavior. Adult attendance at the nest has dropped off significantly. Over the past two weeks, when food arrives, the rate of adult to offspring feeding slowly decreased, and a new sequence has emerged. Observations include the young being fed by the adults, the young feeding after the adult consumes, or the food being brought to the nest for the young independently. Recently, the older chick sat for 5 minutes eating from a newly arrived fish carcass without any assistance from the adult male. Once it had consumed its fill, and its crop was full, it moved away, allowing the younger bird to approach and feed. These are excellent behaviors to witness, and signal the fitness of the nesting pair and their offspring.
The week‐long rains during Week 7 did little to hamper the appetite and growth of the eaglets at the NCTC nest. Food deliveries continue to be diverse, although fish is the typical food provided. We again saw game birds and carrion during the week of rain, which may have played a role in food sourcing. Despite the weather, the adults were relentless in providing for nest‐bound chicks, so that the necessary calories and nutrients are obtained. Towards the end of Week 7, the eaglets were observed feeding themselves. The older eaglet even tried to be assertive by wrestling food from the parent; a good sign that independent behaviors are emerging....right on schedule! With four weeks remaining in the nesting period, the food sources are essential so that growth, muscle mass, and feathers develop normally so that fledging will occur on schedule.
Juvenile feathers begin to slowly cover the natal down, which will aid the chicks in maintaining body temperatures. Longer, warmer feathers mean that the adult eagles can brood the young less often, unless bad weather persists. The adults can instead spend time roosting in a tree, watching the sky for intruders or away hunting. The staff at NCTC confirmed the presence of an adult nearby on branches of the nest tree or flying overhead. Last week, many viewers noted that the adult female was absent from the nest for a long period. During her absence, the adult male was present seen in the nest, and within a 24‐hour period, the female returned. It is important to note that raptor parents will begin to transition their young from constant care and presence so that independence and fledging behaviors are encouraged. Factoring in the similarity in size between the parents and their young at this time helps us to understand why the presence of 2 large and 2 almost full sized chicks would make the nest quite crowded!
At approximately 6 weeks old, the eaglets are standing in the nest, walking around, and Spreading their wings, which shows that they are developing appropriately at this stage. dark juvenile contour feathers are replacing the soft, grey down in patches, making the birds appear multicolored. The older eaglet has juvenile feathers covering most of its back, yet eventually the feather displays will be similar. Features on the beaks are more pronounced, with length and color changes occurring. Along the mouth opening, the color is changing from pale pink to pale yellow, beginning to look like an adult beak. The eaglets are almost as tall as the parents when standing. Balancing on their feet continues to be a new skill along with wing stretching and flapping. They practice walking from one side of the nest to the other side, before congregating together along the edge.
Many viewers noticed the adults away from the nest last week for long periods of time. It is important to remember that when out of camera view, the adults are possibly foraging or soaring above the nest to warn off intruders in their territory. Actually if you listen, you can often hear eagle calls close to the nest, and this indicates that one of the parents is often nearby. Now that they brood the eaglets less often during the day, they will roost on a branch of the sycamore tree. If you watch the eaglets, you’ll see them frequently fix their gaze upwards towards an unseen object. Our team observed one adult sitting in the tree directly above the eaglets early Monday April 25th! As soon as an adult returns, the eaglets walk over to seek food or to be near the adults. On warm days last week, the adult, typically the female, spread its wings out and mantled the eaglets, which hovered under her so as to be protected from the midday sun. This is innate behavior the adult displays to enhance the survival of its young who cannot get water except from its food sources.
Fish was the dominate food delivery last week. As each eaglet feeds, pay attention to the large bulging area under its beak. That bulge is called the crop, a muscular pouch that functions as a storage space for excess food. You have noticed that the adult continually feeds the eaglets large strips of food. Once the stomach is full, the excess is held in the crop until the stomach has room to digest the next portion. The eaglets release food from its crop to the stomach, digesting small portions until the crop is emptied. Since eaglets need lots of food during the rapid weight gain stage, the crop serves as an essential adaptation for birds.
Our eaglets are growing rapidly, and each day display behaviors and features one would expect of a 3‐4 week old chick. The eagles are now in the nestling period of development. Signs that their development is proceeding on course are: facial features become more distinct, the natal down feather patterns becoming darker and denser, increased wing movement, and evidence of a large crop. In the last two weeks, we have observed the young move around the nest, no longer simply laying in the nest bowl. This was a major accomplishment, and we saw each eaglet find a corner of the nest, to spread its wings, and display those large yellow feet. While they appear to be quite large, most 3‐4 week old eaglets only weigh around 2‐4 pounds, depending on the hatch date. Occasionally, both parents were seen away from the nest, but never for extended periods. Often the parents are roosting in the tree above them, or as we saw last week, both parents were patrolling the sky to stake their territory and warn predators who may be too close to the nest.
A wide variety of food has been brought to the nest over the past few days. Fish continue to be a constant food source for the nesting family, yet within this week alone, the adults brought three prey deliveries to the nest that were .... Birds! We observed the remnants of a duck (identified by feather patterns), and another duck, possibly a grebe (identified by its foot shape). Finally, we were fortunate to catch the moment when the female land into the nest with a grey bird in her talons. This bird (possibly a pigeon), was plucked and distributed to the chicks all within a 10‐minute time period! Watching the parents feed themselves as they feed the young, gives us an indication that they are choosing food sources that are beneficial to all the nest dwellers. Food sourcing is a major part of an adult eagle’s role at this crucial time, and as generalist feeders, eagles show that they are flexible and willing to diversify their diets, especially when it comes to their offspring!
On March 16th and March 18th, we experienced the asynchronous hatching of two eagle eggs at the National Conservation Training Center. Approximately one day after each hatching, sounds and chick movement could be heard and seen in the nest.
Competition for Food
It has been one week since hatching, therefore the parents are focused on sourcing any food that can provide a high energy content and is readily available. We have seen a nest full of fish, mainly carp, and a squirrel this week! At times there have been up to 6 fish in the nest, all ready for regular eaglet feedings. This protein-rich diet, delivered as thin strips of meat to the eaglets, will help them grow at tremendous rates in the coming weeks.
The eaglets are now in the rapid phase of growth, showing changes in size and features in one week, yet a size differences between the two eaglets is evident. Feeding behaviors between the two chicks differs due to hatching dates. The older chick has a two day advance in development, and so it will often push ahead to get food. The second chick is somewhat smaller, still developing structural muscles. However this diet will help the younger chick quickly develop the size, skills, and coordination needed to compete for food and attention. The older chick is making sounds to get more parental attention, with the younger chick is slowly beginning to chirp. All of these changes are very normal process, and such competition skills are needed to ensure that the eaglets can fledge and the next adult population is be fit and successful.
Eaglet Features and Protection
The chicks are covered with their first set of feathers called natal down. These feathers are fluffy and light grey but do not provide much warmth, so the parents will only stay off the nest bowl for brief periods. The adults also vigilantly watch for predators by scouring the sky for potential threats and occasionally signaling each other through calls, as their young are vulnerable in the nest. When not seated on the chicks, they stand beside the nest bowl observing the chicks or if they fly away, the flight lasts only 1-2 minutes!
After 10 days, we should expect to see the natal down change into thermal down, a warmer, thicker feather, typically light to medium grey. Facial features are developing rapidly with a beak colors changing from black to black tipped beaks with white colors near the nasal bridges. Large black eyes opened after 1-2 days, allowing the chicks to begin observing their surroundings and locating the parents.
In the coming week, we should begin seeing further development in the second chick, neurological changes in both chicks (wing movement, enhanced sounds, etc.) and more interactions between the chicks and their parents.
Two eaglets hatched this week in the bald eagle nest at the National Conservation Training Center near Shepherdstown, WV. The eggs, laid on February 8th and February 11th,are typically incubated for 35 days on average. Asynchronous hatching occurred, therefore once hatched, the eaglets will be of different ages and sizes.
The first of the eagle eggs hatched during the night on 3/16/16, after 37 days of incubating. One day after hatching, the eaglet presented itself at the top of the nest bowl, and by the evening of 3/17/16, it was being feed fish by the parent. The second hatching began Friday March 18th, approximately 36 days after being laid. Hatching began slowly, but but the end of the day, and eaglet was released. Both parents continue to take turns, often 2-3 times per day, sitting on the nest, getting close to the hatchlings, and making sure to cover the bowl. Rarely will the parents leave the eggs, and if this occurred, they return to brood within minutes.
The weather over the past few weeks gave us a chance to observe essential nesting behaviors from our pair: egg turning, nest raking, and mantling. Regardless of which adult is on the nest, egg turning occurs several times per sitting. This is done to ensure even temperatures for the embryo and to keep the egg in close proximity to the adult body. In the past two weeks, significant amounts of nest raking have been observed, where birds pick at moss and dry grass to maintain and re-shape the nest. This behavior also helps to insulate the nest bowl from cold drafts and precipitation. One, was seen on cold windy days when either rain or wet snow occurred induced mantling, a unique behavior that can serve two purposes. Mantling, done by spreading out the wings horizontally while seated is used to: a) shield the nest, eggs, and young hatchlings from weather, or b) cover a food supply from other predators.
Due to the unseasonably warm weather and direct sunlight, the adult eagles were seen panting while sitting on the nest bowl. This behavior is quite normal behavior for large, darkly colored birds, and a good sign they are attempting to thermoregulate their internal temperatures. Eagles give birth to young who are altricial (the parents bring nourishment to the eaglets initially), so any moisture they obtain comes from the food they ingest. If normal spring weather conditions return, those cooler temperatures will help the hatchlings (and the parents) to maintain their body temperatures and grow.
The nest camera angle will remain close to the adults to ensure better viewing of the new offspring. As they mature and begin to move, views of the maturing eaglets will be easily seen from any angle.
Our eagles have a 2nd egg, laid around 6 PM Thursday. If all goes according to plan, this egg will hatch on March 17th, St. Patrick's Day. Another egg may be laid about 3 days from now, for a full clutch of 3 eggs. These eagles must start brooding their eggs as soon as they are laid, because if they don’t those eggs will get cold enough to kill the embryo inside. The result of this type of incubation process is asynchronous hatching with a brood consisting of nestlings of various sizes making feeding times often very competitive affairs.
Our eagle pair has an egg! It was laid on the evening on Feb. 8. Over the next week or so, about 3 days apart, another 1 or 2 eggs will be laid. Because of the normal winter weather, eggs must be incubated immediately as they are produced to remain warm and viable, even before the clutch is complete. As incubation is about 35 days, the result is that at full hatching, the nest will contain young of different ages/sizes. This first egg will hatch on about March 14, so mark your calendars.
Both female and male have developed bare brood patches to take turns warming the eggs, but the larger female will do most of the incubation work. In turn, the male will do most of the fishing/hunting during this period. The eggs are rolled over by either parent about every 1 or 2 hours to make sure that the lighter yolk does not rise to the surface and the delicate blood vessels that cover the yolk stick to the shell surface, killing the developing chick.
Only the biggest birds such as eagles, the largest owls and penguins are capable of cold season nesting, having the large body mass to create enough heat to incubate eggs and brood young in the harshest weather. The early nesting of the NCTC eagles means that the young will hatch just as the major spring runs of Potomac River fish, such as suckers, commence, as well as the spring hatching of other prey items such as Canada goose goslings or litters of rabbits. The early nesting also means the young are out of the nest before the hottest period of summer when moisture may be limited.
It is the beginning of 2016 and over the last few weeks, the pair of American bald eagles at the National Conservation Training Center in Shepherdstown, West Virginia, have been observed carrying large sticks to prepare their nest for egg-laying that is likely to occur at the end of this month or in early February. This is the 11th season that the nest has been active. This is apparently the same pair of bald eagles that has been together since 2011 when a new male replaced the resident male that had been nesting with the same female since the nest first became active in 2006. The birds are not banded with either metal or colored leg bands so identifying the birds is a matter of faith.
Bald eagles reach sexual maturity, attaining a pure white head at the age of four to five years. During the last three years there was evidence of territorial competition as adult birds fought over the nest site to determine who would claim the huge nest structure located at the top of a 100 foot-tall sycamore. Last year, single immature dark-headed birds, possibly born from the pair in years past, were seen in and around the nest, before the adult pair's nesting behavior went into full swing.
The bald eagle builds the largest nest of any North American bird and among the largest tree nests ever recorded for any animal, up to 13 ft. deep, 8 ft. wide, and weighing up to a metric ton. The birds typically remain paired for as long as they live and will often return to the same nests, with the birds living 25 years or more.
The larger female will lay 1-3 eggs and both birds will continually incubate them during the harshest winter and spring weather, in snow, rain and high wind. Bald eagles feed primarily on fish with an occasional waterfowl, turtle, snake, groundhog, squirrel or rabbit taken as well. Roadkill deer and other animals are also consumed.
One to three young have been fledged most years at this location, with two young fledged in 2015, out of three young that hatched.
Bald eagles nesting in the region usually stay here their entire lives, as long as they have access to open water to feed on fish. The resident population appears to be growing and there is great competition for nesting areas. The Chesapeake Region is also an important stop for bald eagles migrating from other parts of North America during spring and autumn.
You have probably noticed the new camera, mount location, and enhanced picture quality. We are excited to see these birds from a whole new perspective this year.
Join us for this new nesting season. Please don't hesitate to ask us questions.
This project is a partnership between the US Fish and Wildlife Service, Outdoor Channel, and the Friends of the National Conservation Training Center. We also acknowledge the Town of Shepherdstown, WV, the Hancock Wildlife Foundation for their support; and the many dedicated eagle fans from around the country and the world who have been with us from the beginning of this endeavor.
The first fledgling first left the nest on June 4 with the second young first leaving the nest on June 10. However, both fledglings appear to be staying in the surrounding area to be fed by either parent both in or away from the nest. Note all the bleached fish bones that have collected over the last few weeks. The young can often be heard calling for food. The adults will continue to feed the fledglings for weeks, sometimes far from the nest with the Potomac River only a few hundred yards away. The fledglings will soon develop the ability to obtain food on their own, including catching live fish and other prey, and consuming carrion. The fledgling period coincides well with the reproductive period of Canada geese and many mammals thus live prey and carrion is abundant. This year was a real challenge for adults and nestlings alike, including harsh winter weather, torrential rain and wind events, and nest competitors. Two of the three nestlings survived to fledging adding to the strong record of reproductive success at this location. The two young are expected to disperse widely over the next few years, perhaps to returning to the area when they reach full breeding condition, with a fully white head and dark back, at about 5 years of age. Because none of the young are banded, we will never know for certain if any immature eagles seen in the area over the next few years are the young from this nest or whether they are from other nearby eagle nests on the Potomac and Shenandoah Rivers.
It appears the oldest eagle nestling fledged either late on June 4 or early today. This is right on time as first flights usually occur around 10 weeks of age and the nestlings are now 71 and 69 days old. The youngest should fledge over the next few days. Early flights will be very short to surrounding trees. If the fledglings land on the ground, it may be difficult for them to get airborne again. The fledglings will not stray far from the nest and will continue to be fed by both parents either away from the nest or decreasingly within it for a number of weeks. The parents do not teach the fledglings how to catch fish or other prey. Like flying, eagle feeding skills develop instinctively.
The eaglets are now 60 and 58 days old. There have not been a large number of food deliveries to the nest over the last week and the young have been very hungry. The Potomac River has been running high and muddy, and this may have limited fishing success by the parents. The young have shown increasing ability to feed themselves which makes any prey item difficult to share between them as the young defend their food by mantling over the item. The weather has been hot and humid, and you can see the young panting hard to stay cool while seeking any available shade. Although the young are fairly large, the parents can often be seen perched above the nest or on a tree nearby to insure their safety.
The young are now 46 and 44 days old, with more complete dark feathering. This plumage marks them as juveniles. The young will retain these darker feathers until they begin approaching reproductive maturity at around 4-5 years of age. At that time, white head and tail feathers will become apparent. Another striking physical change in the young over time is eye color: between now and adulthood, the juveniles' eyes - currently a dark brown - will lighten in color and eventually transition to a pale yellow. New behavioral developments include attempts at feeding from carcasses on their own, and exercising their wings. The young are about half way to fledging. Contrary to popular belief, birds are not taught to fly by their parents, rather, the development of that behavior is completely innate. On April 30, an immature eagle was seen around the nest. With optimal breeding habitat in short supply, there is strong competition for nesting sites and we interpret this as an indicator that our local eagle population is indeed healthy.
The nestlings are now 29 and 27 days old. The oldest is starting to replace some its thermal down with dark feathering on its wing. The parents have added new dry grass, some sticks and some greenery to the nest. The young are pretty expert at helping to keep the nest cup clean by squirting their droppings over the rim. The young still sprawl on their sides like puppies when they sleep, with their wings and feet spread awkwardly, possibly to help stay cool. Soon they will be always sitting more upright, with their feet under them.
The young, now 21 and 19 days old, are growing quickly into their enormous yellow feet. Their diet has varied over the last few days to include a mallard drake, unidentified mammal remains as well as the staple fish. One of the pair mantled over the duck carcass which is common behavior if a raptor is defending the kill from a competitor. During the weekend, the adults sometimes acted as if an intruder was in the vicinity. The male often brought in new sticks and rearranged the outer perimeter. The young appear to be able to thermoregulate well and no longer require much brooding. On sunny days, shade is limited and the birds have to sprawl out and pant to stay cool or stand in their parents shadow.
As sometimes happens in a normal asynchronous hatch, the last eagle hatchling is at a huge natural disadvantage in terms of obtaining food and protecting itself. Yesterday, the youngest and smallest hatchling died, appearing to be crushed by the carcass of a fish brought to the nest by one of the adults during feeding time. While sadness is a very human response to death, it is important to remember that the nestling death is a part of the natural selection process.
Billions - if not trillions - of young animals die each year. If every one of them survived, the globe would be overrun with animals from the tiniest of insects to the largest animals on earth, such as elephants. However, every environment presents challenges for survival. As a result, only those individuals that can best adapt to their environments will survive. If they live long enough, they will go on to reproduce, passing on to the next generation any traits that may have assisted with survival. This process is fundamental to life as we know it.
For an eagle, heron, or other large predatory bird, having 3 young in a single nesting season is an extreme maximum. In most cases only 1-2 offspring survive. In a typical year, these eagles have fledged 1-2 young. Only once or twice have they had 3 young fledge. There were also two years when no young survived at all - the eggs were damaged by snowfall, or the hatchling starved.
The death of the smallest nestling means the 2 remaining animals have a better chance of survival, with more food and parental care available to them while they are maturing in the nest and after leaving the nest when they are still fed for a few weeks until they are fully capable of feeding themselves.
The nestlings are being well fed with fish and the days have been pretty warm. The young may sometimes be so warm that they have to pant to cool off. The nestlings are hatched with a coat of natal down, which does not have much insulating ability so that chicks must be brooded for warmth particularly at night. Natal down is replaced by thermal down beginning around 10 days of age. Thermal down has good insulating qualities and by 15 days chicks are typically able to thermoregulate on their own. The emergence of browner juvenile feathers usually begins around 27 days.
The young are growing quickly and proportionally; the size difference based on age can be easily seen. In addition to fish, the eagles have been feeding on rabbit, squirrel and what appeared to be a ground hog. With the oldest birds now 12 and 10 days old and youngest now 7, you can see how the larger birds do not have to brooded as much as the smallest to stay warm as the high temperatures in Shepherdstown have been in the low to mid-70's. One limiting factor in these warm spring days is that the young must obtain all their moisture from the fresh flesh of the fishes and mammals they are fed. There is no way the parents can bring them water and the young will be unable to drink until they leave the nest when they are at least 10 weeks old.
Because they initiate egg-laying in the winter cold, Potomac bald eagles must initiate incubation with the first egg which leads to asynchronous hatching. The result is what we see in this Shepherdstown nest: young of varying levels of maturity. As we can see here, the most mature hatchlings are larger, more vigorous, coordinated and alert, getting first crack at any food offered by the parents. The more mature hatchlings can often out-maneuver their smaller, less mature hatchlings when the parents are presenting food. Sometimes the larger birds appear to trample and lay upon their smaller siblings in the nest cup. Luckily there is so much fish food (apparently smallmouth bass, golden redhorse suckers) available at present that all the young are receiving sufficient nourishment. The only limiting factor appears the parents' motivation to keep feeding each hatchling until they are all satiated, often one by one - largest to smallest. A week from now, the 3 young will also vary in their feathers with the oldest having thermal down, with more control over its own body temperature, and the youngest still in natal down requiring more brooding from its parents to stay warm.
The 3rd egg hatched around 8 AM this morning. The parents appeared to notice when the hatchling was struggling to get out of the open shell. The first hatched young is now 5 days old and the 2nd is now 3 days old. The adults have proven themselves very adept at bass fishing; at this point there is abundant food for all. Temperatures are trending warmer during the day, although we anticipate below freezing temps during the night for the next couple of nights. If all chicks survive and fledge, it will be the first time in several years since three have fledged from this nest.
As the sun went down yesterday evening, 2 hatchlings were fed and then brooded. Then came a huge thunderstorm with pouring rain. The brooding adult tried to prevent the young and remaining egg from becoming wet/cold directly with their chest and with their draped wings. The last egg may hatch over the next day or two. If it is not viable, it may become buried beneath the thick nesting material as the hatchlings and their parents move around. The bass fishing has apparently been very good, and a possible rabbit carcass was also visible among the fish carcasses.
The 2nd egg appears to have hatched this morning. If everything continues to go well, the 3rd egg should hatch in the next few days. Based on the abundance of fish delivered by both parents to the nest, the hatching has been perfectly timed with Potomac fish runs.
The first egg hatched around 2 pm on March 22. The hatchling received its first fish meal a few hours later. Today at 1 day old, the young appears vigorous and is avidly feeding. The first egg was expected to hatch around March 19, so either completed incubation is a running a little late and the first egg laid has finally hatched or one or more of the remaining eggs may not be viable. In this cool weather and before they attain their thermal down, the hatchlings will have to be brooded to keep warm. The fish brought to the nest are often hard to identify, but over the last few days the parents have caught suckers, bass, and fish in the Pike family.
The snow in the nest quickly melted away making it easier for the pair to incubate its 3-egg clutch. If each of the eggs were successfully brooded for the necessary incubation period (approximately 35 days), they will hatch one at a time in the order they were laid, with estimated hatching dates between March 19 and March 26. After hatching, the nestlings covered with natal down, will be unable to thermoregulate for about 2 weeks, requiring constant brooding from either parent to stay warm. After about 15 days, the nestling's natal down will be replaced by thermal down which will can keep them better insulated from the cold.
Thursday, March 5 has been a hard day for the eagle pair; trying to incubate 3 eggs in a blizzard with up to 10 inches of snow in the nest. Many times the incubating eagle was totally covered in snow with only their heads free. When the birds transfered incubation duties, it was quite a production. It sometimes appeared that one bird nudged the other to get up off the eggs. There was alot of snow for the bird rising from the eggs to brush off their feathers, and the eggs had to be momentarily exposed to the cold, before the other animal carefully settled to brood. Sometimes it appeared the larger female only allowed the male to brood the eggs for a very short time before replacing him. If anyone ever doubts the powerful instinctual drive of wild animals to breed, just take a look at these birds gamely brooding their eggs with no respite, while laying in a giant bowl of nearly a foot of freshly fallen snow. It is truly amazing to see.Over the last few days before the snowstorm hit, the birds were consistently bringing large suckers into the nest, suggesting the fish are running in the Potomac River. However, fishing opportunities may decline over the next week, as the Potomac is flooding due to its many muddy tributaries upstream filling with heavy rain and snowmelt. The next few days may be decisive, determining whether or not this clutch of eggs will remain viable. It can be painful to watch how extreme weather wreacks havoc on wildlife.
Based on what food items have been delivered to the nest, food has either not been abundant or the birds are simply eating away from the nest. Parts of the Potomac River have had significant ice cover (last week the Shenandoah River downstream in Harpers Ferry was completely frozen over) and the absence of open water can set limits on where bald eagles and other fish-eating birds can over-winter. Eagles are able to fast for many days without harm.
A third egg has arrived! We anticipate that this egg should hatch around March 26th. If each egg is viable, by that date the nest will contain nestlings that are 7 days old, 4 days old and 1 day old. Feeding these eaglets may be quite challenging with considerable competition for food between the nestlings of such a wide range of sizes and stages of development.
On February 15, the female eagle laid a second egg. If all goes well, this egg is likely to hatch around March 22. Hopefully the disruption at the nest on February 15 did not lead to the cooling of the 1st egg. The eagles also encountered a snow storm (with around 3 inches of snow accumulation) and freezing temperatures earlier in the week.
Only large birds such as eagles and great-horned owls are massive enough to create enough body heat to keep eggs warm in the dead of winter. Incubation of eggs during winter times the hatch for the more temperate weather and abundant prey available in the early spring - such as early runs of suckers on the Potomac.
The egg laid February 12, 2015 in the afternoon is likely to hatch after about 35 days, around March 19. One or 2 more eggs are likely to arrive over the next 4 to 5 days, with accordingly later hatching dates. Although the female will likely do most of the incubation, both sexes have developed a brood patch and will continuously incubate the eggs, turning them every so often for even warming and to maintain a healthy relationship between the embryonic membranes and shell. The eggs must remain covered to avoid cooling.
Update #2 - New Eagle Sighted in Nest
For the first time, we observed a visitor to the nest interacting with a member of the nesting pair in a non-threatening manner. This morning at around 10 a.m., a sub-adult eagle was spotted in the nest, and stayed for over an hour. Two separate times, one of the adult eagles joined the sub-adult in the nest, and did not appear to be disturbed by its presence. One could infer that this might indicate the sub-adult fledged from the same nest years ago. However, bald eagles don't live in family groups that stay together over the years. Typically, sub-adult birds disperse widely before reaching maturity, seeking unoccupied territory in which to breed. This sub-adult eagle was seen moving twigs around in the nest this morning, and may have been honing its nest building skills.
We can tell from the head feathers that the sub-adult eagle is likely between three and four years old. Its feathers are mostly dark, and have not yet been replaced by the white head and tail feathers, (and completely dark back) which indicate sexual maturity at around four (to five) years of age. If the juvenile continues to frequent the nest, interactions with the adults could become combative(as the sub-adult will compete with the nesting pair for food and space.
Competition among eagles for choice nesting areas is not uncommon, given that eagle populations have increased in our area while suitable habitat is limited. Conflicts between eagles can be very aggressive, resulting in injury or even death, similar to what we observed during the 2012 nesting season. The NCTC cam provides us with a window into the wild, and our standing policy is not to interfere in any way with the natural life cycle of the eagles that nest here.
American bald eagles are early breeders. In our relatively northern state of West Virginia, egg laying is often in early February, when the average temperature is frequently near freezing. Any egg must be incubated immediately and for approximately 35 days in order to maintain viability. Some images of the nest from February seem to indicate there may have been an egg laid, but without incubation over the last 24 hours, that egg would not be viable.
Once an egg is laid, both sexes will take turns incubating it. Both sexes develop a brood patch to effectively cover the eggs and warm the hatchlings. If winter weather is successfully endured, a full clutch of two to three eggs being laid over a two to five day period culminates over a month later in eggs hatching one or two days apart, resulting in eaglets at different stages of development being fed on abundant spring runs of Potomac River fish. This is different from songbirds which breed during the warm spring/summer period and only begin incubating their eggs once the full clutch is complete, ensuring that eggs hatch at the same time.
It is the beginning of January 2015 and over the last month, our pair of bald eagles at the National Conservation Training Center in Shepherdstown, West Virginia, has been observed carrying large sticks and leafy material in their talons to prepare their nest for egg-laying that is likely to occur at the end of this month or in early February. This is the tenth season that the nest has been active.
The larger female will lay 1-3 eggs and both birds will continually incubate them during the harshest weather. Bald eagles feed primarily on fish with an occasional waterfowl, turtle, snake, with rabbit, deer shank or roadkill consumed as well. One to three young have been fledged most years at this location, with two young fledged in 2014.
This is the same pair of bald eagles that has been together since 2011 when a new male, with a note-worthy black feather spot on his head, replaced the resident male that had been nesting with the same female since the nest first became active in 2006.
During the last three years there was evidence of territorial competition as adult birds fought over the nest site to determine who would claim the huge nest structure located at the top of a 100 foot-tall sycamore. There have been single adult birds, likely not from our pair, seen in the nest over the past several weeks.
American bald eagles reach sexual maturity (attaining a pure white head) at the age of four to five years, the bald eagle builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal, up to 13 ft. deep, 8 ft. wide, and weighing up to a metric ton. The birds typically remain paired for as long as they live and will often return to the same nests, with the birds living 25 years or more.
Bald eagles nesting in the region usually stay here their entire lives, as long as they have access to open water to feed on fish.
The resident population is strong and there is great competition for nesting areas. The Chesapeake Region is an important stop for bald eagles migrating from other parts of North America during spring and autumn.
Join us for this new nesting season. Please don't hesitate to ask us questions.
This project is a partnership between the US Fish and Wildlife Service, Outdoor Channel, and the Friends of the National Conservation Training Center. We also acknowledge the many dedicated eagle fans from around the country and the world who have been with us from the beginning, and who have provided a great deal of support for this project.
Many people have been asking about the camera angle. Unfortunately, the National Conservation Training Center had to do some 'last minute' maintenance on the camera before the eagles nested. A critter (probably a squirrel) chewed the coax cable and we had no picture. During the work, the camera housing tilted a bit and it doesn't take much movement to change the view angle. With the eagles in nesting season, we can't disturb them to fix the camera angle. A truck and crane are required to reach the nest as the tree branches are not safe for climbing at 90 ft. So, we'll have to make the best of this until we can make a proper fix, after nesting season.
These eagles must start brooding their eggs as soon as they are laid, because in winter if they don’t those eggs will get cold enough to damage them. The result of this type of brooding process is asynchronous hatching with a brood consisting of young of various ages/sizes.
As the first egg was laid on President's Day - February 17 we should have expected the first hatching on Monday March 24 (after 35 days) and the second egg laid on February 20 should hatch Wednesday or Thursday, with the last egg hatching on Sunday. If any of the eggs got chilled during our challenging weather spell over the last month, they may not hatch. So keep your fingers crossed and think warm weather thoughts.
Because the weather is currently pretty cold, the young will have to hatch while being brooded; they cannot be exposed for more than a short time. If it doesn’t warm up soon it may be difficult for the parents to feed the hatchlings, if they have to be exposed for any length of time to do so.
With their long incubation times, one of the reasons the eagles do not typically nest in the later spring or summer is due to the high temperatures the young will be exposed to in the unshaded nest, with the danger of dehydration. It is a fact that the young in the nest will find it difficult to get water in any form except as moisture in the foods they eat, such as the flesh of fresh fish. The eagle parents don’t bring water in their gullets/mouths or absorbed on their belly feathers to allow the young to drink (as Old World sandgrouse do). Another important reason for early nesting is to the time hatching to correspond to the boom in prey populations - runs of suckers on the Potomac River and the hatching of goslings and other baby animals.
Almost all American birds with altricial young have little or no access to free water except from the moisture found in their food. Thus most Passerine (perching) birds don’t typically nest in the hottest months of the summer when even eating the moistest food items such as earthworms may not make up for the water lost in maintaining the hatchling's body temperature and water balance. Much like the eagles, Passerines nesting in spring time the hatch to correspond with the highest populations of caterpillars and other easy-to-eat invertebrates.
The current camera angle cannot be changed until the birds fledge in June. However as the young mature in the nest over the next 3 months it should be easier to observe them regardless of camera angle.
On March 2-3 the eagles endured an icy rain and snow storm (3-4 inches of snow accumulating), continuing to faithfully incubate their full clutch of 3 eggs. Nest views showed the female or male calmly sitting on the nest, completely surrounded by fresh snow in near zero temperatures. Only the largest raptors, including the great-horned owl and largest Antarctic penguins, such as the emperor penguin are massive enough to be able to incubate eggs in the mid-winter cold.
Both the female and male eagles have developed a brood patch, a spot bare of feathers on their stomach to be able to directly warm the eggs with their body heat, skin to eggs. The parents must turn the eggs regularly to ensure that all eggs in the clutch are incubated evenly and that all surfaces of each egg receive equal warmth. Regular turning moves an egg's contents by small increments, keeping membranes and the embryo from sticking to interior shell surfaces, which could cause embryo death. Hopefully none of the eggs have become chilled; if so they will not hatch. Only time will tell.
We have an egg! This year the eagles appeared to have delayed egg-laying at least 10-14 days during this stormy winter period, rather then risk losing their first clutch to snowfall as has happened a few times in the past.
The eagles, both female and male, begin to incubate the eggs as soon as they are laid. We can anticipate 1-3 eggs per clutch, laid one day apart. As this first egg was laid on President's Day - February 17 we should expect first hatching in about 35 days, on about March 24.
Any subsequent eggs will hatch a day or two later, resulting in young of different maturity levels in the nest.
Last year two young were successfully reared on a steady diet of freshly-caught Potomac River fish with an occasional turtle, waterfowl, snake, rabbit, groundhog and scavenged deer shank thrown in for variety.
The eaglets are maturing very fast. They have been observed self-feeding on fish brought by their parents, exercising their wings, competently walking around and preening as if they are adults. However they still sometimes sleep on their sides, with their bright yellow feet splayed, a posture they will never assume when they leave the nest for good in a number of weeks. The nest has been kept very tidy this year with no loose debris or old turtle shell and other prey remains. Are the sprigs of fresh sycamore leaves brought in by the adults or are they simply falling into the nest from above? The cool weather has benefited the eaglets as they rarely have to pant to prevent heat stress. Until they leave the nest, all moisture they ingest has to come from their food alone. The parents do not bring water on their feathers for the nestlings to drink, although a few species of birds, such as the sandgrouse, a desert bird of Africa and Eurasia, do exactly that.
The NCTC eaglets are growing fast as they go into week 5 since they hatched. They are now in that “awkward” stage with their large feet and wings growing and they are just learning how to maneuver around, not yet so gracefully. They easily maneuver to defecate outside of the nest, which is pretty amusing for any viewer to watch. Both chicks have been fed an abundance and a variety of food. People have observed mostly fish, but also squirrels, being brought to the nest. In just another 5-7 weeks, we’ll start seeing them fully grown. It will be here before you know it. They will also have added some weight as they develop their flight muscles after they leave the nest. Their wingspan will be as large as or slightly larger than the adults at that time.
Now that the NCTC Eagle Cam is back up and working, there has been plenty of action, and the chicks are already starting to get bigger and have become vocal and active. A variety of food has been brought into the nest - from large flopping suckers and waterfowl, to squirrels and rabbits - there have been some diverse options.
Steve Chase, Division Chief writes:
We had indications that an intruder was in the vicinity of the nest on Saturday and again on Sunday morning. Tuesday afternoon, our pair was involved with an extended altercation with another adult bald eagle who is likely interested in our pair's territory.
One of our birds stationed itself on an adjacent tree watching, and soon, the other (likely the male) flew across our entry road chasing another adult bald eagle. These birds fought overhead while our other bird stationed itself in the top of the nest tree. The fighting went on for some time until the interloper bird was finally chased west away from the nest tree.
We are not sure what the conclusion of this altercation was, but both of our birds are back in normal mode. We'll see if there are any additional challenges.
Remember this is wild nature we are watching. Nesting habitat is at a premium, thus nesting pairs will be challenged occasionally.
Two eaglets hatched this weekend in the bald eagle nest at the National Conservation Training Center near Shepherdstown, WV. The first eaglet hatched on 3/16/13 at 2pm after 38 days of incubation.
The second eaglet hatched 3/17/13 at 3pm after 39 days of incubation. The eggs were laid February 6th and 9th. In the next 3 months they will grow from eaglet to adult and by mid-June they will fledge the nest. Feeding time is approximately every 1-2 hours with fish caught from the Potomac and other food, as available.
The link below will show a still photo image that refreshes every 30 seconds. If you right-click your mouse over the image you can save, print or e-mail a picture.
Our NCTC eagles have been doing great. The two continue to switch off, as the other adult gets a break and hunts. The male has been very active as a brooder, which is unique in what we’ve seen in past years. It also appears they’ve brought some pine needles in the nest, which is also new. Fluff and nesting material continue to be abundant and has been brought to the nest frequently. The eagles have made a very nice, deep, insulated nest cup within the nest itself. Every day that there hasn’t been snow is a greater advantage for the eggs survival, and for the eagles not to have to relay as they have for several years before.
In the mean time, Blackwater National Wildlife Refuge, located in Cambridge, MD just had their second chick hatch today, February 27th. Our NCTC eagles won’t be far behind. We’re expecting the hatching to occur right around March 13th.
On Wednesday, February 6, 2013 our NCTC eagles laid their first egg. The second egg quickly followed on Saturday, February 9. We have observed the male and female switching off on incubation duties, but rarely will you see the eggs left alone for very long. In fact, 98% of the time one parent will remain on the nest. Laying on these eggs day in and day out can be tense, so the parents will call each other for reprieve. Since tonight is calling for snow, let's watch them and see that not rain, snow or wind will keep these parents from protecting their young. They will be there to protect these eggs through adverse weather and even potential predators. In approximately 35 days, we'll all be watching for that first eaglet.
As the blustery temperatures start plummeting in Shepherdstown, WV at currently 17 degrees, our eagles are setting up house in their beautiful sycamore tree located at the National Conservation Training Center, just a hop, skip and a jump from the Potomac River, where they have nested every year since 2007. Each year, the eagles add sticks, grass, and other material to their nest, so every year, the nest gets bulkier and heavier. Our NCTC nest is approximately 7-8 feet in diameter and could weigh nearly a ton by now. Eagles add material to their nest every year to build the sides up higher in order to keep the eaglets from falling out. You might think this is not necessary, but the nest needs to be so big because, even though the chicks are small when they hatch, within a couple of months they get very large. You can imagine with, potentially, three very large chicks and two adults, each with a wing span of 7 feet, the nest can get very crowded, very quickly. Check out the photo of a man installing the eagle camera. You can see just how big the nest really is.
The eaglets are now at a point where their bodies are thermoregulating, and no longer need to be brooded by their parents. Both chicks are growing very quickly and, at just three weeks old, are both larger than the size of a full grown chicken. Although there doesn't seem to be as many fish in the nest as when they were younger, this may be because the chicks may be growing enough where they are eating larger amounts and at a more rapid rate. At one point, food was so abundant, each of the parents, simultaneously, had one chick at each end of the nest, and were each feeding them a different fish, so that neither of the chicks had to compete for food and had the full attention from each of the parents. Have any of our viewers seen this take place with other eagles? This was a first for us. Another interesting observation is that, when the chicks are lying down, they seem to lie down on their sides like a puppy, instead of an upright position like their parents. As the food remains start to collect flies, and although we cannot smell through cameras, we can only imagine what the aroma may be like; the parents have begun bringing in new nesting material. Before we know it, we'll see feathers replace their down, and their wings will begin flapping, in preparation to fledge.
The second egg hatched on Friday March 16, 2012. Both eaglets are moving about the nest and food seems to be plentiful. Because the eaglets were born days apart, they are of different sizes. If there is enough food, both young will thrive. If not, the larger may monopolize the food. So far, fishing has been great! Many viewers are wondering what the black spot on the male's head is. This black spot is the remains of the black head feathers juvenile eagles have. At around 4 years old, the juveniles lose the black head feathers, are replaced with white and are sexually mature. This tells us this male is somewhere around 4 years old.
The young birds have soft grayish down which will soon be replaced with black feathers at around 5-6 weeks. According to the American Bald Eagle page, it can take 24-48 hours for an eaglet to work its way out of the egg using its egg tooth. Once newly hatched, eaglets are born with wobbly legs that are too weak to hold their weight, and their eyes are partially closed, limiting vision. Their only protection is their parents.
Eagles feed their young by shredding pieces of meat from their prey with their beaks. The parents gently coax the chicks to take a morsel of meat from their beaks. As you can see from the webcam, the parents will offer food again and again, eating rejected morsels themselves, and then tearing off another piece for the eaglets.
The young birds grow rapidly, they add one pound to their body weight every four or five days. At about two weeks, it is possible for them to hold their heads up for feeding. By three weeks they are 1 foot high and their feet and beaks are very nearly adult size.
The male brought in 2 fairly large fish on Tuesday while the female was incubating the eggs. The female appeared to pant heavily as she brooded the eggs in the hot sun. On Wednesday, a crack appeared in one egg and by around 3:30 PM, the hatchling had struggled completely out of the broken shell as the male stood by either looking closely at the hatchling or re-arranging sticks. He eventually settled on the hatchling and the unhatched egg to brood them. Later around 4:30 PM he got up to feed on the fish remains from the day before, while the hatchling lifted its head, opened its mouth and moved its wings next to the unhatched egg.
On Saturday, February 18, at approximately 3:45pm a young adult eagle intruded on our NCTC nesting pair. The pair successfully fought off the intruder until about 6pm and maintained control of their territory. The 2 eggs are expected to hatch around the middle of March.
Unfortunately, for the eagles nesting at Blackwater NWR in Cambridge, MD their 10-day old pair of eaglets died February 26, due to, what was believed to be an intruder. You can view the footage on YouTube. Craig Koppie, Eagle Coordinator/Raptor Biologist with the U.S. Fish and Wildlife Service/Chesapeake Bay Field Office climbed the tree and examined the nest contents. After reaching the top of the nest, two dead eaglets were observed and collected. Craig states:
"There are several possibilities that could have caused or potentially led up to the cause of the nest failure. Factors could include 1) weather event or disturbance during night hours that caused the adult to get off the nest thereby chilling the young, 2) condition during gestation and development of embryo, 3) prey contamination, 4) parental issue- behavioral problem or condition leading to the killing of offspring or lastly, intraspecific competition whereby a rival eagle displaced one of the resident eagles and killing their young, which is a domineering trait of an intruder over taking a nest and/or territory.
Competition between eagles for choice nesting areas or the lack of suitable habitats for newly formed pairs have led to increased conflicts resulting in death or injury to adults including aggressive combat or eaglet killing at nest sites. Clearly, eagle cams have captured moments in the lives of eagles that we could not have imagined otherwise. Although these situations appear to be acts of violence and difficult to observe, we must appreciate the fact that it is nature's way to insure that the strongest and most fit individual of each species continues to thrive."
Although we never want to witness a nest failure on the Eagle Cams, like what occurred at NCTC last year and this year at Blackwater, it is encouraging that eagle numbers are on the rise throughout the country. Bald eagles are an endangered species success story, having been removed from the Endangered Species List in 2007.
Eagle Update, Tuesday February 7, 2012
We got our first egg of 2012 in the late afternoon on Sunday Feb 5. Thus far, the weather has been good, the egg has stayed warm and dry, and food is being delivered to the nest. Here's what Bent says about eggs and incubation:
"Two eggs almost invariably make up a full set for the bald eagle, sometimes only one, and rarely three; in two or three cases four eggs have been found in a nest, but these may have been the product of two females. The eggs vary in shape from rounded-ovate to ovate, the former predominating. The shell is rough or coarsely granulated. The color is dull white or pale bluish white and unmarked, though often nest stained. Very rarely an egg shows a few slight traces of pale brown or buff markings."
We can expect another egg over the next day or so; and if we are lucky, another one towards the weekend.
"The period of incubation is about 35 days, according to the most careful observers, though it has been otherwise estimated. Both parents assist in incubation and in the care of the young. Mr. Nicholson tells me that at every nest he has visited after dark he has found both birds at the nest, one incubating or brooding and one perched near it. In one instance the incubating bird remained on the nest until the climber nearly reached it."
"In conducting the shifts a rather definite formula was observed. The sitting bird would give a sharp chitter when wishing to be relieved; the mate, if within hearing, came to the eyrie, moved up close, and the exchange was quickly made. If the eggs were left for only the shortest time, they were carefully covered with a great quantity of grass, stubble, and other convenient nest material, and the scrupulous covering and uncovering process would sometimes last from five to ten minutes. . . ."
more at birdsbybent.com
Our eagle pair have been tending to the nest and we are getting very close to the time that we could see some eggs. Nesting competition continues to be an issue here in Shepherdstown, as we have seen at least one intruder come through in the past week or two. The healthy population of bald eagles in the region is causing more competition for nesting habitat. You can see a video of the intruder being violently ejected from the nest by one of the resident birds at this link:
We will be keeping a close eye on happenings here at NCTC and will keep you posted as events unfold. We all hope for a nesting season that is quieter than last year, but only time will tell.
As we get close to the holidays, nesting activity at the NCTC has been moving along nicely, with the new male settled in with our long time female.
We'll continue to see preparation activities going on over the next month, and hopefully we'll then settle into a more "normal" nesting season. But this is wild nature, so only time will tell how things play out over the next several months.
Happy Holidays from the NCTC Eagle Cam Crew
Things have quieted down at the nest with occasional visits by both the resident female and what appears to be our new resident male. We'll have to wait until next season to hopefully get another clutch.
There has been no sign of the old resident male, and unfortunately the remains of an adult bald eagle were found on the NCTC property recently. The condition of the bird was very poor, so it is unlikely that we will ever know if the bird was our original resident male. Because of the proximity and degree of decomposition there is a possibility that it was "our" bird, however it did not have a brood patch (a patch of skin on the belly where adult birds with eggs or young offspring have removed feathers in order to better incubate their young). While we would anticipated that the resident male that has been nesting at NCTC in recent years would have had a brood patch, we will never know for certain whether this deceased eagle was in fact the resident male.
It has been confirmed that the dead eagle found at Antietam did not have a brood patch. This means this eagle was almost certainly not the long-term resident male from NCTC, given that the resident male would probably still have had a brood patch. We will do our best to confirm the gender once the bird has arrived at the National Eagle Repository.
The resident female eagle and the new eagle have been observed mating; behavior which indicates the new bird is almost certainly male. We think it is too late in the season for eggs to be laid, but we are keeping an eye on the nest. Eagle behavior is complex, particularly during the breeding season. The behavior we are seeing at NCTC may be unusual, but by no-means is it unheard of.
The absence of the long-time resident male at NCTC has concerned many of our eagle cam viewers, and there are several possible reasons why we aren't seeing him. The most likely reason is that the new male may be in better breeding condition, and as a result, replaced the original male. While we will not be able to know with certainty what happened to the resident male, we do have some new information.
Yesterday, we received a report from our National Park Service neighbors at Antietam National Battlefield that a dead eagle was found inside the park. NCTC sent a team to examine the bird, and based on measurements the team obtained and compared with typical eagle gender patterns, it seems very likely this bird was male. The Fish and Wildlife Service's National Eagle Repository will perform a necropsy, and only then will the gender of the bird be absolutely confirmed. This process is expected to take several weeks. Even if the bird is determined to be male, it will still be impossible to confirm with any certainty whether this bird was the resident male at NCTC.
Below, we've provided some additional information about eagle behavior which may help explain some of what our eagle cam viewers have been witnessing this season:
- Eagles are at risk of agonistic encounters (aggressive social interactions with other members of the same species).
- Aggression and territorial defense behaviors increase during the breeding season.
- Violent exchanges between eagles can result in the exclusion of one bird from the area, and in some cases, serious injury or death.
Mating for life; nesting behavior:
- Eagles do generally mate for life, usually selecting a new mate only when one dies.
- Re-pairing can occur within months or a few days. In one case, a female attracted a new mate in four days. In another documented case, the male of an incubating female disappeared and a replacement male appeared the next day and began delivering prey to the nest.
- Typically eagles prepare nests 1-3 months prior to egg-laying. However, nest repair can continue year round. In some cases Bald Eagles will lay replacement clutches if the first attempt fails.
- Because of the lateness of the season, it is highly unlikely that the NCTC eagles will attempt another nest. Return trips to the nest may indicate an instinctual behavior brought on by the time of year and the individuals' hormone levels.
Local eagle populations by numbers:
- In 2010, the WV Department of Natural Resources located 36 Bald Eagle nests state-wide and MD Department of Natural Resources estimates 500 breeding pairs in Maryland.
- These numbers are extremely encouraging for a bird recently removed from the Endangered Species list. However, with higher populations, there will be additional competition for suitable territories, nest sites, and mates.
This morning we confirmed a sighting of two adult eagles in a tree located near the nest tree. While we do not know the current whereabouts of the original male resident eagle, he was seen on March 21st and was not injured. We have not seen the male resident since. The new eagle, we now believe to most likely be a male, has been making trips to the nest on a daily basis. This indicates to us that the resident male eagle has either moved on or is not willing to come within a certain radius of the nest because of the new bird. The resident female is still occupying her territory and is keeping quite close to the nest site. It is very difficult to determine whether an adult eagle as male or female; typically the female is larger (we initially assumed the new adult eagle was a female because of its large size). Without capturing the new adult to examine it- which would pose a potential risk to eagle - it has been difficult to confirm whether it is male or female. One method we're exploring is listening to the eagles' calls: some females have a much lower pitch relative to males. We will continue to provide information as the situations changes. Meanwhile, we encourage those of you who are interested to learn more about eagle biology. (For example, this Cornell University Web page is a good resource: http://bna.birds.cornell.edu/bna/species/506/articles/introduction.) We have a fascinating piece of eagle biology playing out at NCTC. We are glad that you are able to experience this along with us.
Earlier this afternoon, NCTC released a statement regarding its resident bald eagles. The statement includes information from a raptor biologist explaining why human intervention is not a good approach when it comes to nesting birds, and eagles in particular. To learn more, you can view the brief statement on the Web at:
In upcoming weeks, we will do our very best to post regular, factual updates that are grounded in science. Over the weekend, we were able to confirm the presence of a third adult eagle near the nest, and we are almost certain that it is a breeding age female. Typically, the presence of a new female means she is competing with the established pair of eagles for the current nest and the territory that goes with it. Nest competition is a common occurrence in areas with healthy eagle populations, meaning the total population of eagles near NCTC has likely increased in recent years.
We have also confirmed multiple sightings of the male eagle who is part of the established breeding pair. The male does not appear to be injured, and seems to be in good health. The eaglet which hatched on March 17th has died and the remaining egg is not likely to hatch given that it is not being regularly incubated by the parents.
We do have biologists on staff here at NCTC who are available to share their expert assessments of the situation. In addition, our land manager has been communicating with another raptor biologist based in our Chesapeake Bay field office. There is general agreement that if the new female eagle is successful in chasing off the current female, the new female will then need to recruit a male to join her. However, it is likely too late in the nesting season for success in laying, incubating and hatching any new eggs.
You may wonder why there is competition over this nest - and there are several potential factors. Eagles prefer to nest in the tops of large trees located near rivers, lakes, and other wetlands. The NCTC nest is located very close to the Potomac River, which is a plentiful source of fish for nesting eagles to hunt. In addition, eagle nests represent a considerable investment of effort to construct: they can be up to 10 feet in diameter and weigh up to 2,000 lbs. And finally, as mentioned above, nest competition frequently occurs in areas with a significant eagle population.
While we are still working to confirm what the current situation is with the adult eagles, we would like to remind all of our dedicated eagle fans that the eagles who nest on the NCTC campus are wild birds. As such, they are exposed to the same environmental pressures any eagle faces in nature. While the NCTC camera provides us with an opportunity to observe these magnificent birds in their natural environment, it is not our policy to interfere with them in any way.
The first of two eggs in the nest hatched yesterday, March 17th, in the morning. Two eagles have been confirmed to be present at the nest as of this morning. One has been generally staying higher in the tree (above the camera). The behavior we are seeing from the adult eagles is a little different than is typical. At this point U.S. Fish and Wildlife Service staff are working to confirm whether these two eagles are the mating pair. More information will follow soon.
We are excited that the eagles have been working hard to set up the nest for another nesting season. Dawn, midday and dusk seems to be the best time to view them right now. There has been mating activity occurring for more than a week, which is a good sign.
We have been able to adjust the new cam to work fairly well in night vision mode, so we are ready for the eggs to be laid. We are hoping to see the first egg within about about two weeks, toward the beginning of February.
We are getting closer to a new nesting season, and are working hard to be able to install a new, high-resolution camera on December 6. This cam will allow a much better view of the birds.
The current camera has broken down, thus the blue screen. Please bear with us as we work to get the system up and running again. More information soon.
Action in the nest has declined a great deal with the departure of the young eagle. We plan on going up in the nest sometime later in the month to install a new HD camera, an improved camera mount and other equipment. Keep an eye out for our adults, who are occasionally visiting the nest.
Our young eagle has been flying around the nest area now since its first flight since on or around June 13th. While the bird has learned to fly, it has only started to learn to hunt, leaving it often times in the nest yelling to its parents for dinner.
Note the turtle shells in the nest. Turtles have been easy prey this season for the eagles and we have counted at least four shells (probably more) in the nest.
With its rudimentary hunting skills, the young eagle will soon head off away from its Shepherdstown home, not to be seen again in these parts. Our adults will very likely hang around for the rest of the summer, and in the Fall begin to tidy up the nest for the next nesting season.
The last month has seen our young eagle get to full size and continue to grow in the feathers necessary for flight. Food has been abundant. As we get close to the first flight, keep an eye out for the adults to stop bringing in food. This will give extra incentive for our juvenile to take that first leap of faith out of the nest, very soon.
Our weather has been unusually cool and windy the past few days, with temperatures dipping into the 30s in the mornings.
Our eaglet continues to grow to near adult size and further gain its first primary feathers. Continue to watch for increased pre-flight activity like jumping and stretching of wings, although we still have a good six weeks before an expected first flight.
The adults continue to bring in a bounty of food, but they are now leaving for longer periods and do not stay around as much supervising the safety of their now near adult-sized offspring. As this brief note is written, neither adult is at the nest tree.
Earth Day 40th Anniversary
As our eaglet celebrates it's first 30 days in the nest, it continues to grow with the fine diet delivered on a regular basis by our two adults. You'll note that the first plumage is beginning to grow in, they are the darker patches you can see, and the young eagle will begin to preen itself of its first layer of grey down feathers with the growth of the new feathers.
While the adults will still feed the eaglet, it has opportunities to pull off food from the various fish and other prey left in the nest. It is also quite mobile and able to move around the nest. Again, note that even when you see no adults in the nest, they are almost always perched in the tree, keeping close watch.
Once the first plumage is more developed, you'll be able to note the first pre-flight exercises-jumping and flapping. But don't expect that for a few more weeks yet. Remember the time from hatch to fledge is about 12 weeks, and this eaglet hatched on March 21, so the fledge will occur in late June.
Happy Earth Day.
Our eaglet continues to grow at a rapid rate. They usually fledge about 12 weeks after the hatch.
Lots of fish are coming up to the nest, so there is plenty of food-- it always helps to have the Potomac a 30 second flight away from the nest.
The adults have been leaving the youngster "alone" more often, but in reality there is always an adult perched within a few feet of the nest.
More soon as the eaglet continues to grow into a "teenager".
Our young eaglet is growing fast thanks to the abundance of food and the good parenting from our eagle pair. The good weather doesn’t hurt either.
Here’s how Arthur Cleveland Bent, in his Life Histories of North American Birds, a classic series that describes the lives of many North American Birds, describes the development of the eaglet’s plumage.
“When first hatched the downy young eaglet is completely covered with long, thick, silky down, longest on the head; it is "smoke gray" on the back, paler gray on the head and under parts, and nearly white on the throat. When the young bird is about three weeks old this light gray or whitish down is pushed out and replaced by short, woolly, thick down of a dark, sooty-gray color, "hair brown" to "drab." The plumage begins to appear on the body and wings, scattered brownish-black feathers showing on the scapulars, back, and sides of the breast, when about five or six weeks old; at this age the wing quills are breaking their sheaths. At the age of seven or eight weeks the eaglet is fairly well feathered, with only a little down showing between the feather tracks, and the flight feathers are fully half grown.”
On Sunday, March 21, 2010, at about 4 PM the eaglet hatched out. This is great news since this is the one egg out of four that made it this year, and it was right on time.
There will be lots of action now with the new eaglet. Plenty of food will be brought into the nest, and there will be ample time to watch this now tiny eagle grow.
Spring has sprung here in the eastern panhandle of WV. While there are still big snowdrifts to melt in the region, most of the surface snow has melted; the temps have warmed; and the red winged black birds are back--a sure sign of Spring. The eagles continue to keep their solitary egg warm and dry. They will be tested in the next few days as we have a rain event that promises to be a strong storm, but the temperatures will be in the fifties and sixties. In the event of heavy rain, watch how the eagles will extend their wings to "tent" the area of the nest with the egg. We are expecting that this egg will hatch in about ten days.
Our eagles are tending to one egg. The other egg, which we felt had questionable viability, is now not seen, likely under the layers of grass that continues to be brought into the nest. The egg that is being incubated was layed on February 13th. This would put us into a hatching trajectory of on or around March 21. Let's hope the weather gets better and does not throw any more snowy obstacles in the way. Continue to keep an eye out for fish being brought into the nest--March is the best time to catch big walleye on our vicinity of the river, and these birds can carry in some big fish when they are hungry.
We are now in the long waiting period to the hatch. The adult eagles incubate the eggs for about 35 days or so. The eagles are diligently taking care of their two eggs, and fortunately the weather has been relatively fair.
The eagles are keeping the eggs warm with their brood patch, a featherless section of skin filled with blood vessels. The little "dance" they do when going back on the eggs ensures that their brood patch is in contact with the eggs.
Watch for the rolling of the eggs throughout the day, about once an hour. This is done with their talons rolled up to protect the egg, and the rolling action ensures that the embryo does not stick to the eggshell.
We still feel that one egg is likely viable and the other probably is not, but they may surprise us.
Also keep an eye out for live fish being brought in from the Potomac River, which is a few hundred yards down the hill from the nest tree. The fishing on this stretch of river is excellent, and some of the fish brought in are big ones. Big or small, the fish don't last long.
We have had several days of fair, but chilly weather here in Shepherdstown. Our eagles are tending to two eggs, including a fourth egg that was laid last Saturday, February 13th. Whether or not both are viable is subject to discussion, but we believe that at least one is, hopefully both. Weather is expected to warm up through the weekend, with a chance of snow/sleet/rain on Monday. This will be the bird's next challenge.
The winter weather has been a major hindrance for the successful nesting of our eagle pair this year. With snow amounts approaching or exceeding 40 inches in the last week, this has served to overwhelm our birds and quite likely result in the first three eggs being non-viable.
Here's a history of the eggs laid thus far:
- 2/2 10:15pm--First egg laid.
2/6 2:12pm--Second egg laid.
2/9 6:00pm--Third egg laid.
Within hours of the second egg being laid, it became apparent that by their behavior that the eagles had lost their eggs in the deep snow that filled the nest.
A third egg was laid during the second storm on Feb. 9th, but the eagles have not been attentive to keeping the egg warm, and it seems likely that this clutch is no longer viable.
Time will tell if the eagles will lay more eggs. The odds are typically 50/50 for a second clutch. With this problem happening early this year, we are hoping that there will be additional eggs produced.
We had a moderate snow event overnight, and this morning our viewers noticed that the first egg had been laid. Not the best weather, but these adults are diligent and know what it takes to keep the egg dry and warm.
Look for up to two additional eggs over the next several days separated by at least 24 hours.
More snow is forecasted for Friday and Saturday, which will prove to be a challenge to the eagles.
The Shepherdstown eagles are working hard to prepare the nest for some new young. Despite a "hiccup" where we had to replace the nest cam last week, everything is going smooth towards eggs being laid in very early February.
The changing of the cam at this late date had to be done carefully, and we did the work with one of the Fish and Wildlife Service's "primo" eagle biologists onsite at the nest tree and in consultation with the Fish and Wildlife Service's Elkins Field Office.
You'll notice that we have again changed to position of the cam to provide a better view of the entire nest.
Thanks to our partner, Outdoor Channel, for hosting the live feed from the nest--check it out!
Activity in the Nest is starting to pick up, and we are noticing the eagle pair hanging out in the nesting tree more often than a month ago. You'll notice that the nest is starting to look more tidy again as our pair begins to fix things up for the winter nesting.
Look for our new live feed, which will be established in the near future. More on that soon.
The eaglet fledged around dawn on Saturday, May 30. While this youngster can now fly, it still does not have the skills necessary to hunt, and thus will be back in the nest often for meals which will continue to be brought in by the adults. There's still time for more eagle watching before the fledgling leaves for good, in several more weeks.
Our young eagle is preparing to fledge, and we expect this to occur in the next week or so. Keep an eye on the cam and the blog for the actual fledge date and time.
Once the eaglet has fledged, it will stay around the nest for several more weeks, so there will be plenty of time to see it coming and going from the nest.
It has been a wet and chilly spring thus far. The second egg finally vanished a week or two ago, leaving us with the one eaglet for the season.
The adults have spent a good deal of time keeping the eaglet warm and dry. The first sign of new feathers are appearing on the eaglet, and it continues to grow steadily. Our proximity to the Potomac river ensures that their is a bountiful supply of fish, but we have noticed several squirrels and other small mammals. Likely most of these are road kill, although a freshly killed squirrel means that the eagles could be catching them live.
As of today, we have one eaglet, and one remaining egg. It seems unlikely that this last egg will hatch out, the longer it takes the more improbable a hatch becomes. There are many reasons that eggs can not be viable, including cold temperatures and moisture. We'll probably never know what happened this year, but we can celebrate our one new eaglet.
Our first egg hatched out on Saturday, and the young eaglet looks healthy. The other two eggs are still in the nest, but have been hard to see. We hope they hatch out as well in the next several days.
Typically, bald eagle eggs will hatch in about 35 days, but there are instances where the time is as long as 45 days.
Remember that not all eggs are viable, although these adults have been very diligent this year in keeping the eggs warm and dry.
There's been a lot of action at the NCTC nest this week. The first egg of the season was laid on Saturday, January 31, and the second egg was laid Monday, February 2. We are hoping for a third egg in the next 12-18 hours or so. Only time will tell, but this pair has a good track record for three eggs.
Here's Bent's description of the eagle eggs:
" Eggs.--Two eggs almost invariably make up a full set for the bald eagle, sometimes only one, and rarely three; in two or three cases four eggs have been found in a nest, but these may have been the product of two females. The eggs vary in shape from rounded-ovate to ovate, the former predominating. The shell is rough or coarsely granulated. The color is dull white or pale bluish white and unmarked, though often nest stained. Very rarely an egg shows a few slight traces of pale brown or buff markings.
The measurements of 50 eggs from Florida average 70.5 by 54.2 millimeters; the eggs showing the four extremes measure 78.8 by 56.2, 71.1 by 57.6, and 58.1 by 47 millimeters. The eggs are ridiculously small for large a bird. (Compare the relative sizes of the eggs of the ruddy duck, the sandpipers, or the hummingbirds.) Consequently the little eaglet requires a long time to develop."--[Published in 1937: Smithsonian Institution United States National Museum Bulletin 167 (Part 1): 321-333]
Incubation is about 34-35 days, where both eagles will take turns keeping the eggs warm. The nest and the parents will protect the eggs from the dangers of cold and dampness, but we are always wary of bad weather, as it can have a devastating effect on the eggs, as happened in 2007.
The eagle cam has had approximately 32,000 hits since we cranked it back up 22 days ago.
The nest is now empty, with all three eaglets now successful fledglings. They are still in the area of the nest, and continue to eat fish and other things brought to the nest by the adult pair. As the summer progresses, we'll see less and less of them, and they will finally move on, not to be seen around this nest again.
It is the first of June and our three eagle offspring are nearing the time for their first flight. Here's what Bent has to say about this time in the eaglet's development:
"With the increase in size and strength comes an increase in activity, with more time devoted to play and exercise in preparation for flight. Activities begin by walking or jumping about the nest, which soon becomes trodden quite flat, picking up and playing with sticks, learning to grasp objects in the talons, and stretching and flapping their growing wings. With tail raised and head lowered the eaglet backs up to the edge of the nest and shoots its liquid excreta clear of the nest to form a "whitewashed" circle on the ground below. Later on the flight exercises begin in earnest, of which Dr. Herrick (1924c) writes:
After a while a simple routine is established--raising the wings until they seem to touch over the back, taking a few strokes and jumping; the flapping gradually comes to take their feet above the floor of the eyrie and at eight weeks of age they may be able to rise two feet or more in the air; this ability attained, they are liable to go higher and higher and in a fairly stiff breeze, which helps to sustain if not stimulate them, they begin to soar and hover. In 1922 we said "good-bye" to the Eaglets more than once before knowing the long practise they required to produce that perfect coordination of muscles and nerves which was necessary for confidence in the air. During the last week of regular eyrie life in that year they would sometimes rise to a height of fifteen feet, and soar for a full minute, going even beyond the confines of the nest and always with talons down to facilitate landing upon their return.
At last the day comes for the eaglets to leave the nest. Sometimes they do so voluntarily; but in some cases it seems necessary to use persuasion. In Dr. Herrick's (1924c) "first season with the Eagles the young seemed disinclined to leave their eyrie and were finally starved out and lured away." After two days of scanty feeding and two days of fasting, "as the old Eagle with the fish was circling just above the nest the Eaglet was jumping with legs rigid and flapping frantically; suddenly it leaped into the air, and for a second seemed to hang, as if poised over the eyrie; at that moment the circling Eagle began to scream, and swooping down at the hovering and now screaming youngster passed him within six feet; a minute later the Eaglet, still holding to the air, drifted fifteen feet or more beyond the margin of the nest; with vigorous wing-beats it began to move eastward, following the mother bird with the fish and made a full mile in its first independent flight; it finally landed in the branches of a tree on the edge of a strip of woods and doubtless was there allowed to feed on the tantalizing fish."
For some time after they leave the nest, probably all through their first summer, the young eagles associate with their parents in the home territory and frequently return to the nest or their favorite perches. But they are eventually driven out to earn their own living and seek new territory. They are never allowed to establish a breeding station near their parental home."
Our three eaglets are rapidly approaching the time where they will fledge from the nest. We're estimating that will take place in early June.
Their feathers continue to grow in, and when they open their wings it is amazing to see how big they are after a couple of months of growth. The adults continue to bring lots of fish, and are still careful to ensure all three eagles get their fill of food.
Both adults have been leaving the area of the nest more often now, as the threat of predators is not really an issue considering the size of the young eagles, although one is often seen perched above the nest.
Here’s some info from Bent’s Life Histories of Familiar American Birds:
Although often two, sometimes three, eaglets are hatched, the larger number is seldom raised to maturity, and often only one eaglet lives to grow up. The young hatch at intervals of a few days and the first one hatched, often the female, is larger and stronger than the other. The larger eaglet often abuses the smaller one and gets more than its share of the food, until the poor little one succumbs and dies of weakness and exposure. Dr. Herrick (1932) writes:
Two eaglets were hatched in that season on about April 24 and 28, and the younger bird was handicapped not only on account of its lesser age, but from the tempestuous weather and the shower of abuse it daily received from its older companion. The mother eagle constantly disregarded the needs of its puny infant, but bestowed every attention on her more vociferous offspring. Thus, on May 18, when the eagle brought in a large fish, the older nestling got 76 pieces, but the younger only 2, and a bad drubbing from his nest-mate in the bargain. On the following day rain and hail beat so relentlessly on the great nest that this much abused eaglet, then hardly able to crawl beneath the sheltering wings of its mother, finally succumbed and was trampled into the great mass of withered grass that lined its bed. It should be noticed that this harsh treatment of the younger bird had often occurred when the parent was away and when there was no contest over the food.
Both parents bring food to the nest and both assist in feeding the young. Dr. Herrick (1929) describes the process as follows:
The female eagle has been brooding her callow young, which are now in white down and about two weeks old. She deliberately rises, walks over to the carcass of a large fish, stands on it and begins tearing off small pieces of the flesh and passing them to the three eaglets, which line up before her.
Twenty minutes later the male drops on the eyrie and immediately joins his mate in the work of satisfying the appetites of their hungry brood. The old eagles bend to their task and pass up bits of food at the rate of about five to the minute. At least the passes are at this rate, but the proffered food is not always taken. It may indeed go the rounds, to be eaten finally by one of the old birds.
When the eaglets are older and strong enough to tear up their own food, they are taught to do so. A family feast, presided over by the mother eagle, who has just arrived with a fish, is thus described by the same observer (1929):
Her young, all aquiver with excitement, continue to crouch and squeal, with their wings half spread, but they seldom venture to advance. The old bird now seizes her quarry, which appears to be a lake catfish of about four pounds in weight, and with one foot drags it to the center of the nest.
Standing on it there, she begins ripping it up without further ceremony. With swift thrusts of her bill she detaches large pieces of the white flesh and, taking a glance around at each upward stroke, swallows them in rapid succession. Then to the nearest bird, which by this time has edged up to its parent, she passes several pieces from bill to bill, and goes to work again on her own account.
When eaglet number two has been served in the same fashion, she moves a few steps away; whereupon number one seizes the carcass and, spreading over it, claims it as his own. Squealing, with head down, but for some moments without touching a morsel, he warns all intruders away. Meanwhile the other eaglet, drawing nearer, with head extended, watches the feeding bird and, seldom venturing to interfere, patiently awaits its turn.
We have noticed that this pair of adults is very adept at getting all three eaglets fed. They will first focus on the oldest eaglet, and they will feed it until it is gorged and literally cannot move. Then they move on to the middle one with the same technique. The third, youngest eaglet then gets fed, free from the abuse of its older siblings.
It is a rare thing for three eaglets to fledge, so these birds still have a challenging few months facing them.
We have had an extremely successful hatch, with three healthy young eaglets growing rapidly. The first eaglet was hatched in the wee hours of March 13th. The second eaglet was hatched on March 14th and the third on St. Patrick’s Day, March 17th.
We’re now into the growth stage where the eaglets are being fed every few hours. These eagles will mostly subsist on fish, but the adults will bring in whatever they come across. Dam number 4, right upstream from the nest has lots of spawning suckers and walleye congregating right now offering tremendous fishing for the eagles. Watch for a fresh fish delivery anytime on the live cam. As to other food, today there are the remains of a ground hog in the nest.
The eagles maintained their activity at the nest and after several weeks of mating activity, the first egg was laid over the weekend on February 2nd or 3rd. Unfortunately the cam was down that weekend, and when it came back up there was the first egg. The evening of February 6th, another egg was laid. There is a play-by-play description of the activities that evening on the NCTC Eagle Cam Daily Blog. Another egg was seen on the morning of February 10, making this a clutch of three eggs. The weather has been varied throughout this period, and there were several warm days where the eagles both left the nest and the eggs for a short period of time. There has also been a series of rain and ice events that have tested the pair's ability to keep the eggs warm and dry.