Friday, July 08, 2016

DN2 Autopsy Report

We received a final autopsy report on DN2. The eaglet died as a result of Methomyl toxicity, although caffeine was also present. An analysis of DN2’s liver ruled out lead and mercury as the cause of death. It did not include information on the sex of the eaglet.

What is Methomyl?
Methomyl is a broad spectrum insecticide introduced in 1966 to kill a variety of insect pests. It is registered for commercial/professional use on sites including field, vegetable, and orchard crops; sod farms; livestock quarters; commercial premises; and refuse containers. It is toxic enough that products containing more than 1% Methomyl are not available for homeowner or non-professional application.

How were DN2 and Mom North poisoned?
While we don’t know for sure, Methomyl is sometimes used off-label to kill wildlife species that become problematic. 1% Methomyl products including Golden Malrin, Lurectron Scatterbait, and Stimukil are placed in sweet solutions, including caffeinated colas, to poison animals like raccoon that some consider pests and can cause damage to buildings and farm animals. Given the presence of both Methomyl and caffeine, it seems likely that Mom North found a Methomyl-poisoned dying or dead mammal and brought it to the nest to eat. It wouldn’t have taken much to kill DN2 or Mom North, since Methomyl is highly toxic.  Based on what we observed, Mom North was able to metabolize and recover from what she ate, but DN2 was not. While it is possible that the poisoning was the unintended consequence of a legal use of Methomyl, the caffeine suggests it was not.

For more about the problems of baiting wildlife with Methomyl, follow this link: http://www.sciencemag.org/news/2016/02/regulators-move-limit-wildlife-deaths-misuse-deadly-fly-killer

Is this legal?
It is not. While Methomyl and many other pesticides and insecticides are legal when used in a manner consistent with labeling, it is illegal to go off-label and use them in a manner for which they are not intended. Fly bait is legal when used according to direction and illegal used in any other way. There may be state and federal penalties for people caught misusing it, depending on state and federal law, and what species are killed.

What are you going to do about it?
We have already reported the incident to the Iowa State DNR and the US Fish and Wildlife Service, and will report it to the EPA and the manufacturer of the most likely culprit, Golden Malrin. We will also use our RRP website, Facebook and Twitter audience to help spread the message about misuse of Methomyl and let people know that they can petition their states to reclassify Methomyl fly baits as restricted products should they choose to do so. We would love to say that this was an isolated incident, but a quick search for “golden malrin raccoon” reveals just how widespread the practice is. Google it and join the discussion!

Do you know who did it?
No. There is a lot of variability in eagle home ranges. While immediate nest defense/core territories tend to occur within 100 square meters or so of the nest, hunting territories vary considerably.  One study documented bald eagle summer home ranges that varied from 3 square miles to 18 square miles depending on age, nesting status, and available resources. But other studies have found even wider ranges in nesting bald eagles, including 37 square miles for a pair in Louisiana. The landowners in the immediate vicinity of the nest have expressed their commitment to conservation.  With bald eagles searching and scavenging for food over a large area, there is no way to know exactly where it cam from. We are not an enforcement agency, but we have reported what we know to enforcement agencies.

We don’t believe that anyone meant DN2 or Mom North any harm. But people need to know that off-label poisoning kills unintended targets and can have serious legal consequences. We don’t believe that anyone meant DN2 or Mom North any harm. But people need to know that off-label poisoning kills unintended targets and can have serious legal consequences. This may also be a good day to check garages, basements, and storage sheds to see what noxious and toxic herbicides, rodenticides, and insecticides are on hand that have tragic consequences for wildlife, pets, and humans. Want something to replace those highly toxic chemicals? Check out the Bio-Integral Resource Center (http://www.birc.org/) and their list of least-toxic pest control products: http://www.birc.org/2012Directory.pdf. Even if you can't go completely toxin-free, you can reduce harmful consequences by using products correctly and choosing the least toxic option. You can help by sharing and spreading the word to prevent the unintentional killings of bald eagles and other animals.

Note that Methomyl is toxic enough that the Environmental Protection Agency (EPA) and Methomyl manufacturers have agreed to limit use on certain crops to reduce risks to drinking water: http://bit.ly/29yhNcY. EPA and manufacturers have also reached an agreement to stop making and selling some fly bait products and to add information to the label that clarifies the approved uses. EPA believes that these changes will reduce the illegal use of methomyl fly bait products which can kill wildlife, an issue that was reported to EPA by a number of states.

Are you an academic studying this issue? Please contact us by emailing amy@raptorresource.org.

Friday, May 27, 2016

Intervention at Decorah North Nest

As watchers at the Decorah North Nest know, female eagle Mom North brought some tainted prey into the nest on the afternoon of May 25th. She fed DN2, who promptly died, and ate some herself. Until we shut the cams off, horrified watchers saw a very sick Mom North struggling in the nest.

Neil Rettig and veterinarian Laura Johnson monitored the nest through a private channel. As the night passed, Mom North began to recover from whatever the prey had been tainted with. After she flew off the nest on the morning of May 26th, we knew we needed to make a plan to recover DN2. We wanted to autopsy the eaglet to determine the poisoning agent and prevent Mom from feeding DN2 to DN1 and killing DN1 as well.

The morning started with a call to Kike Arnal, who had climbed into the north nest last fall. Like Neil, he expressed some concern about going into the nest itself and recommended that we try to recover DN2's body with a hook or catchpole. Fortunately, Neil was available to climb. Several of us are versed in rope technique, but the North Nest is very tricky to access and Neil is the only one of us with tree spike experience, which he used to avoid potentially injuring the eagles with a crossbow bolt or line. While Neil, Laura, and Dave Kester made a plan, Amy Ries got busy working on the permit side of things.

Bald eagles are protected by a number of laws, including the Bald and Golden Eagle Act, the Migratory Bird Treaty Act, and the Lacey Act (introduced in 1900 by an Iowa congressman). It is highly illegal to trespass on an active bald or golden eagle nest or take, possess, sell, purchase, barter, transport, or export or import any bald or golden eagle, alive or dead, including any part, nest, or egg. The penalties are severe and may include a fine of $250,000 or two years of imprisonment, which is doubled for an organization. Should we be found to have broken the Bald and Golden Eagle Act, we could also lose our banding permits, which would end our banding program. While these laws may seem harsh, they have been an important part of returning the bald eagle to the American landscape, and we had no intention whatsoever of running afoul of them.

Amy contacted Deanne Endrizzi from the US Fish and Wildlife Service, and Pat Schlarbaum and Bruce Ehresman from the Iowa DNR. She explained the situation and outlined our plan. We would recover DN2 without going into the nest and take the body to Iowa State University's College of Veterinary Medicine for autopsy. The Iowa State DNR and the US Fish and Wildlife Service approved our plan very quickly and we were able to recover DN2's body yesterday afternoon. It is on its way to Iowa State University now. We don't know how long it will take for the results to come back.

Parent in tree
Dave retrieving DN2 from the catchpole
Why did you intervene?
We usually don't intervene in nest life. Wild birds survive and thrive in the presence of things that seem frightening and even awful to human watchers, including bad weather, predators, injuries, and aggression. Although humans found the death of DN3 appalling, it was completely normal eagle behavior. But poisoning is not nature taking its course and all parties agreed that intervention was appropriate and allowable in this case.

What happens next?
We are continuing to monitor the nest remotely, but the camera will remain off for live viewing for the time being. Mom has been in the nest with DN1, who has been fed and looks like a healthy, alert young eagle.

DN1 in the nest on the morning of May 27, 2016. 

Thanks to Neil Rettig, Dr. Laura Johnson, Dave Kester, Kike Arnal, John Howe, Deanne Endrizzi, Bruce Ehresman, Pat Schlarbaum, Allamakee county conservation officer Burt Walters, the US Fish and Wildlife Service, the Iowa Department of Natural Resources, Dr. Steve Ensley, and Iowa State University's College of Veterinary Medicine for their quick action and help. Your advice and experience were invaluable!

We've had some requests for the last video shot from the nest before we turned it off. This video shows an ill Mom in the nest, as well as DN2. If you find it disturbing to watch, please do not follow the link. I witnessed the event and found it very disturbing: https://youtu.be/g4ZC72FurzE




Monday, May 23, 2016

Proposed 30-year take of bald and golden eagles

As a lot of eagle fans are aware, the Fish and Wildlife Service recently announced a plan that would allow companies to kill federally protected bald and golden eagles for up to 30 years. The draft rule will extend the current permit duration of five years to up to 30 years, giving wind farms, power lines and other large projects license to injure, disturb or kill a limited number of eagles in exchange for commitments to avoid and mitigate harm.

The proposed rule has positives and negatives. Before we discuss them further, the public is able to comment on the rule until July 5th, 2016, although comments on the information collection aspects of this rule must be received on or before June 6, 2016. You can comment by going here: https://federalregister.gov/a/2016-10542 and pressing the green 'submit a comment' button on the top right of the page. We encourage people to read through some of the public comments prior to submitting their own.  The Fish and Wildlife Service also has comments and responses available on its website.
Please read the rest of this blog for more information prior to commenting. 

History
The US Fish and Wildlife Service initially introduced a 30-year take rule in 2009. After reviewing the proposal, the American Bird Conservancy took the US Department of the Interior to court in 2014, stating that the Department of the Interior violated federal laws when it created a regulation allowing wind energy and other companies to obtain 30-year permits to kill protected Bald and Golden Eagles without prosecution by the federal government. The court agreed and the rule was invalidated in 2015. The Fish and Wildlife Service introduced a new rule in 2016, although it did not remove the 30-year take.

The current permitting program is voluntary: that is, companies can choose whether or not to join. The Fish and Wildlife Service hopes to bring a greater number of utility companies into the permitting program by changing the mix of penalties and incentives. Although the plan is not without negatives, more participation will yield more data about best practices for wind power and help determine how many birds and bats are killed by turbines.

Negatives
  • The plan seems heavily predicated on mitigation, and there are only a few mitigation methods for wind energy that have been verified to reduce bird kills.
  • Post-construction eagle mortality data is collected by paid consultants to industry instead of third-party experts, which is a conflict of interest.
  • 30 years is a very long time to allow take of bald and golden eagles. Technology and bird populations can change much more rapidly than the proposed take period. 
  • Permits remain voluntary. Companies can chose not to participate at all, although they will suffer legal penalties under the Bald and Golden Eagle Act and the Migratory Bird Treaty Act if they are found to have killed eagles. 
Positives
  • The proposed regulations require applicants for permits with durations of longer than 5 years to conduct a minimum of 2 years of pre-application surveys. Surveys are currently voluntary. 
  • Participation is voluntary and many companies currently opt out. Companies that join the permitting program will be under additional government scrutiny and are required to submit to a five-year review by the FWS, even though the 30-year take permit still stands overall. Companies found to be exceeding their take limits will be subject to additional penalties.
  • The new rule allows for more flexibility in responding to local conditions and adopting new technologies. 
A permitted bald eagle take is problematic to most of us and, as the American Bird Conservancy stated,  "...‘green energy' isn't green if it is killing thousands of eagles and tens of thousands of other birds annually." [link to statement]. However, no form of energy is free of cost to wildlife and wildlands. Coal mining is environmentally destructive in many ways, nuclear energy has a waste disposal problem, birds and bats hit turbines, and electricity produced by all three is transmitted over hundreds of thousands of miles of electrical lines that come with their own collision and electrocution risks. At this time, the Raptor Resource Project supports properly sited wind power as a renewable energy source that helps reduce the threats posed to birds and people by climate change. But we also believe that wind farms can and should be properly sited and operated in ways that minimize harm to federally-protected species.  We will be following the American Bird Conservancy very closely on this issue and encourage those of you who are concerned about the issue to submit comments. Please remember to write clearly and constructively if you do. I have participated in public comment meetings, and incoherent or inaccurate comments are not taken seriously by rule makers.

I was just emailed this link yesterday: http://www.postbulletin.com/news/local/eagle-nest-puts-brakes-on-xcel-energy-wind-turbines/article_d9026393-996a-53f0-9b1b-3e4cef7310c5.html. The article is about an Xcel Energy wind project. Xcel Energy was the first company to sign a Memorandum of Understanding (MOU) with the Fish and Wildlife Service, which Bob was always very proud of. It shows the benefits that participating in these kinds of programs can yield, as well as the challenges of accommodating a bald eagle population with some very different behaviors and territories than those of America's historic bald eagles.

Resources

Thursday, May 12, 2016

Decorah North News: DN3 has died

Eaglet DN3 died sometime yesterday. Why did DN3 die? While it didn't get nearly as much food as its larger siblings, it was still shooting poop yesterday, indicating that it had enough in its system to be pooping and excreting urates normally. However, DN3 may not have eaten yesterday and didn't eat much the day before that. It also didn't help that the weather was cold and damp. Mom and Dad North are brooding based on the older nestlings, who no longer require daylight brooding unless it is raining, snowing, or unusually cold. DN1 and DN2 have thermal down, but DN3's thermal down was just beginning to come in and it would have benefited from brooding.

We suspect there is no one cause for DN3's death. The six-day difference between DN3 and its oldest sibling resulted in insurmountable developmental differences, including dominance interactions that DN3 always lost given its much smaller size, a resulting lack of food, and a lack of brooding before it was really able to thermoregulate on its own. Had the weather been warmer, DN3 might have been able to survive even given the shortage of food and dominance interactions with the older two, but all three together were too much.

Are Mom and Dad North bad parents? No. Eagles don't fit neatly into our human ideas about what good parents are. The older two have been thriving under their care. From an eagle point of view, there is no purpose in caring for weaker young that are less likely to survive than healthy young. Personally, I would love to have seen DN3 survive and I was very hopeful up until yesterday afternoon. But as someone who loves and watches birds, I also need to accept that this is what they do. Humans don't make good parents for birds.

Why didn't we intervene? What happened at the North Nest is completely normal from an eagle perspective. It is well-documented that the youngest member of a three-nestling clutch can die, even though we haven't seen it in Decorah or Fort St. Vrain (eaglets have died because of hypothermia and illness at FSV, but those were very straightforward deaths and didn't involve just the youngest sibling). We haven't intervened in these situations in the past and will not moving forward.

Watching wild creatures doesn't give us ownership over them. The lives of 'our eagles' are truly their own and this was yet another example of how we differ from them. Juliet Lamb has some excellent perspective on the relationship between watchers and watched here: http://daily.jstor.org/wildlife-cams/


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Tuesday, May 10, 2016

What is going on at the Decorah North Nest?

What is going on at Decorah North? The oldest eaglet, DN1, is displaying far more aggression than we are used to towards its siblings. It is upsetting to human watchers, especially since little DN3 takes much of DN1's biting, yanking, and twisting. However, we have also seen DN1 and even DN3 attack DN2. In most cases, the aggressive behavior ceases once the target submits, but we have seen biting and bonking continue past submission at least twice.

Why is this happening?
We don't know. Food certainly seems to be part of the puzzle, since we've often seen the eaglets act aggressively towards one another as they establish a feeding-related pecking order. However, we've also seen aggression break out in circumstances seemingly unrelated to food. For example, DN3 attacked DN2 at around 2pm this afternoon, giving it multiple bites, yanks and twists before DN2 submitted. The eaglets had all been fed well earlier today, so why the aggression? Perhaps differences in age and size also contribute to aggression. I would tend to believe that aggressive behavior is hard to stop once it starts, and I'm very curious whether we will see the drop-off in aggression here that we have seen in Decorah.

While siblicide is rare, aggressive behavior is common. It ranges from the relatively mild aggression seen in Decorah and at Fort St. Vrain to the biting, twisting, and yanking seen at Decorah North, Southwest Florida, and several other nests. I think this looks odd and frightening at least in part because Decorah has tended to lack extreme aggression. But Decorah and Fort St. Vrain could very well be outliers when it comes to eagle behavior. At this point, only the eagles know for sure.

Is DN3 growing normally?
It is very tough to tell with nothing but the two 'Cropzillas' to compare it to. DN3 is growing in thermal down to replace natal down, has gotten larger relative to the other two (seemingly overnight!), and is growing footpads. What we've been able to see of its beak has indicated a fairly regular size and shape in accordance with eaglet growth curves, and its talons are appropriately changing to black.

DN3 is just moving into the steepest part of its growth curve. The next five to seven days will give us a look at whether or not it is growing normally. We'll also look for developmental changes like nest wandering, attempting to stand, and tracking Mom and Dad outside the nest. DN3 has already been observed doing some of those things on warm days and we should see them more often as its thermal down grows in.

Is DN2 growing normally?
Yes, DN2 is growing and behaving normally.

Will DN3 survive?
DN3 is strong, gets fed, participates in nest aggression, and submits appropriately. The eaglets tend to fight with their beaks instead of their talons and, while the aggression looks frightening, DN3 hasn't been badly injured. It is rapidly growing in thermal down, which will help protect it from cold weather and aid nest exploration. Fighting is very hard to watch, but generally rare when one compares the time spent fighting with the time spent laying around the nest and eating.

There are no guarantees, but siblicide is uncommon and DN3 is much stronger than it seems. It often comes back with its own beaking, displaying its own fierceness, or can be seen afterward cuddling up to a former aggressor. We are hopeful it will survive and even thrive as it grows...but again, there are no guarantees with wildlife.

Will you intervene?
Absolutely not. We might consider interfering if the situation were human-caused, but these behaviors are completely normal from an eagle perspective. If we rescued every eaglet we were concerned about, there would be no wild eaglets left to watch. It is very important to keep eaglet behavior in perspective. For the most part, the parents have acted according to our expectations: feeding, interacting, brooding, and in general caring for their family. While the eaglets fight with one another, they spend more time cuddling, eating, and sleeping. While the fighting is upsetting to watchers, none of it is out of line or outside the parameters of normal eagle behavior.

In summary, the worst may happen but we are not giving up on DN3. The next five to seven days will tell us a lot more about its growth. It looks like we are starting to get pinfeathers on DN1, which means its growth will start slowing as feathers take over. While we have never seen this level of aggressive interaction in Decorah, eagles have survived it at other nests. We remain hopeful.

Kay from SOAR also provided some feedback after she was approached about the situation. She agrees that the situation "looks" terrible but that at this developmental stage of the eaglets they don't have a huge amount of strength in their beak.  Right now, those beaks are something like pointy salad tongs. Hopefully all three eaglets will grow well and this will not be a concern for much longer.  







Tuesday, May 03, 2016

Decorah North: DN1, DN3, and today on the nest

Watchers of the Decorah North Nest got quite a shock today after DN1 went after DN3 with a ferocity we haven't seen at any of the bald eagle nests we watch. It looked liked this:
  • Mom North lands on the nest, chasing away a sparrow that was stealing straw from the nest. DN1 and DN2 are huddled together at about 7:00 on the left side of the nest, while DN3 is laying at about 4:00 on the right side of the nest.
  • Both eaglets rise to a sitting position.
  • DN1 dominates DN2, pecking and pulling on DN2's left wing. DN2 submits and DN1 stops.
  • DN1 shoots poop, staying at roughly 7:00..
  • DN3 sits up and walks over to the turkey wing at about 3:00, where it appears to be look up at Mom. Keep in mind that the eaglets are walking on their tarsi, not their feet.
  • DN1 walks from 7:00 to 3:00 and begins a dominance interaction with DN3. In addition to pecking, DN1 bites and pulls on DN3, who submits. 
  • As DN3 submits, it rolls against DN1, scraping DN1 with its talons in what appears to be an accident.
  • DN1 resumes the dominance interaction, pulling and biting at DN3's wing and body and flipping DN3 over. DN3 remains in a submissive posture.
  • DN1 pulls DN3 up by the 'scruff' of its neck four times
  • Mom North, who has been watching the entire interaction, walks over and looks at DN1.
  • DN1 ceases the interaction, although we don't know to what degree Mom North interfered with it. Was DN1 ready to quit given the lack of a response from DN3, or did Mom's arrival distract DN1?


Following this event and subsequent battles, the ugly specter of siblicide - one sibling killing another - leapt to everyone's mind. So how common is siblicide in bald eagles? Sources disagree, with some referring to it as relatively common (University of Nebraska, American Eagle Foundation) and others calling it fairly rare (Hornsby). It hasn't yet occurred at any of our cams - not in Decorah (since 2008), not at Decorah North (since 2016), not in Fort St. Vrain (since 2003), and not during the one year we were able to watch Eagle Valley (2013). Our nests have different parenting 'styles', levels of food availability, surrounding environments, and nest invaders, but to date all eaglet fatalities have been caused by hypothermia, predators, and suspected disease. Why did DN1 take after DN3 and (to a lesser degree) DN2 today? We don't know, but as tough as it was to watch, it wasn't especially prolonged and didn't lead to death.

People also worried about a lack of food deliveries to the nest. While we don't know why parents don't pile up the pantree here as they do in Decorah, birds of prey (even young ones) can go a long time between meals. The eaglets remain healthy, alert, and pooping, which tells us that their digestive systems are working just fine. They are moving around the nest, interacting with one another and with parents, and showing interest in their surroundings. I'm sure they would like a meal, but they aren't starving yet and won't be for some time.

Several people referred to Dad and Mom as 'bad' parents. Again, different nests have different parenting styles, but eagles don't divide neatly into human narratives of good and bad behavior. It is a warm day, the young don't need brooding, and either Mom or Dad have been perched nearby much of the day. They are taking care of their young as they see fit, and we know from studies on human-raised birds that young birds have very different needs than young humans.

We've also been asked if we will rescue DN3. Absolutely not. We might consider interfering if the situation were human-caused, but what happened today was completely normal from an eagle perspective. If we rescued every eaglet we were concerned about, there would be no wild eaglets left to watch. It is very important to keep today in perspective. This is one of the first days we have seen a lot of concern about Decorah North. For the most part, the parents have acted according to our expectations: feeding, interacting, brooding, and in general caring for their family. It is also the first day - the first time - we have seen that level of aggressive interaction in one of the bald eagle nests we watch. But none of it was out of line or outside the parameters of normal eagle behavior. If eaglets died after a warm day with just one meal, we wouldn't have eagles to admire and worry about.

In 2011, a follower sent me a lovely watercolor painting of the fledglings at the Decorah nest. It said "You are braver than you believe, stronger than you seem, and smarter than you know." It remains a favorite artwork of mine and I often think of it when I am concerned about the eagles. As anthropomorphic as the painting may be, eagles are truly stronger than we think and often smarter than we know. As much as we love them, they are only their own and what we saw today was simply part of the way they live their lives.

Note: Hornsby follower gzebear compiled observations from 147 nests checked in an 8 year period and found only a 2% incidence of siblicde in hatches of 2, and 3.8% in hatches with 3. Follow the link to read gze's data, references, and additional comments from contributors to the thread. I think it might be time to revisit the whole subject of three-egg versus two-egg clutches. How common is one versus another? Are there regional differences? Is it an inheritable trait? Do we have more three egg clutches than we used to? It's off-topic here, but I subject that interests me quite a bit.

Tuesday, April 26, 2016

Eaglet Growth and Development: Week Four


D24 and D25, April 25, 2016

D24 is 28 days old today, while D25 turns 26 days old. At this point, feather growth is starting to overtake structural growth as the eaglets approach the half-way point in the nest. Pinfeathers emerged this week, growing at an astonishing rate as they poked out from their keratin sheaths along the edge of the eaglets' wings. Feathers also started to emerge along their backs - the 'cloak' - and sprout from their tails. As beak, leg, and footpad growth began to slow, wing growth sped up, leaving the eaglets with noticeably longer, larger wings by the end of week four.

We also saw changes in behavior. Although the eaglets will continue to compete for food, baby bonking has ceased. This always makes me wonder what functions it serves. We know it strengthens muscles, aids coordination, and helps improve eyesight. Does food competition lead to greater food intake, helping to fuel an eaglet's rapid growth? Does it lay the ground for future social interaction, which includes plenty of body language, vocalization, and dominant/submissive interaction? Does it give parents information about an eaglet's overall heath, or help prompt provisioning? Or is it simply replaced by a new suite of physical behaviors as the eaglets begin to explore the nest and enter the next phase of nestling life? Bonking may have ended, but the eaglets are starting to play with sticks, move towards a full stand, and expand their explorations of the nest. They've also begun noticing the area around the nest, tracking with Mom and Dad as the adults pay attention to the outside world.

So what can we expect to see in week five? Watch for an explosion of dark feathers, leading to an evenly mottled grey and white appearance some time in the next week. The eaglets will begin standing and walking, leading to many mouse clicks as we try to shoo them back to the center of the nest! We may see them begin to tear their own food and we will get to see them 'play house' as they begin moving sticks around themselves and with Mom and Dad. If past years are any judge, Mom and Dad will give them plenty of materials to work with as they pile up the crib rails with larger, heavier sticks!

We've talked a lot about physical changes. We are also entering a period of rapid developmental changes as the eaglets acquire new skills and grow feathers. The eaglets will play cooperatively and competitively, learn to stand, walk, and tear food, and begin moving their wings. Following the appearance of Mom's teakettle whistle, I'm waiting for baby vocalizations to turn into juvenile screes for food! I'm looking forward to watching D24 and D25 move into the next phase of their lives as feather growth takes over from body growth and greater mobility leads to changes in behavior.

The general stages of eagle development are:

Stage 1 - Structural growth. In their first thirty-five to forty days of life, eagles grow very rapidly, gaining weight and building bones, muscles, tissue, and features like tarsi, footpads, toes, and claws. This phase of development slows down about halfway through an eaglet's time in the nest, even though individual features might continue some level of growth.

Stage 2 - Feather and flight-related growth. Eagles grow four sets of feathers - natal down inside the egg, thermal down, juvenile feathers, and adult feathers. Thermal down starts growing at about ten days, juvenile deck feathers at about 20-23 days and juvenile flight feathers at about 27 days, but feather growth doesn't overtake structural growth until thirty-five to forty days after hatch. Flight muscles also begin growing as eaglets wingercize, flap, hover, and eventually branch and fledge.

Stage 3 - Neurological Coordination. Eagle watchers know how ungainly eaglets can seem! As they grow, they become more adept at controlling beaks, legs, wings, and feet. They learn to stand on their own feet, tear food, self-feed, and flap their wings, going from cute but clumsy clown clompers to graceful young eaglets poised at the edge of fledge.

So where is our cortical homunculus in weeks 4-5? I'd tend to think that legs, feet, and wings are accelerating in importance this week, leading important behaviors like standing, tearing, and flapping! I also wonder what impressions are being made now that they are beginning to pay attention to the outside world and have moved from playing with grass to nibbling at larger, heavier sticks. The nest and eagles always have more to teach us!

Things that helped me write this blog, with a few considerations: