Wednesday, April 26, 2017

Eaglet Growth and Development: Week Four

Top to bottom:
Decorah N2B, Decorah North,
Xcel Fort St. Vrain
Most of our eaglets are in their fourth week of life: 26, 25, and 22 days old at N2B in Decorah, 27 and 26 days old at the Decorah North nest, and 31 and 29 days old at the Xcel Energy Fort St. Vrain nest. Over the past 16 days, we've seen eaglet footpads and legs growing and turning yellow, talons darkening from taupe to black, grey thermal down replacing white natal down, and pinfeathers emerging from eaglet wingtips. The eaglets have started coughing up pellets, playing 'house' (moving grasses and other nesting material around), and taking their first steps towards self-feeding ( As their vision, coordination, and strength have improved, the eaglets have expanded nest explorations and started to track events outside their nests, although they also spend a lot time sleeping off big meals and cuddling or even hiding under piles of grass in the cooler, wetter weather at both Iowa nests.

Several watchers have asked if the eaglets are going to fledge soon given their size.  No - as hard as it is to believe, we still have roughly 50 days until fledge at both Decorah nests and 45'ish days until fledge at Fort St. Vrain! Eagles grow very rapidly in their first thirty-five to forty days of life, gaining weight and building bones, muscles, tissue, and features like tarsi, footpads, toes, and claws. But during an eagle's fifth week of life (28 to 35 days), feather growth starts to overtake structural growth. Pinfeathers grow from eaglet wings, tails, and backs; beak, leg, and footpad growth all slow; and wing growth speeds up. So what can we look forward to in the coming week? Remember, the eaglets we are watching range from 22 days (D28 is just starting its fourth week) through 31 days (FSV34 is about halfway through its fifth week).
  • The eaglets should start standing on their feet. This will change nest exploration and poop-shoots. Look out below!
  • Natal down mohawks will vanish and dark deck feather growth will accelerate. Look for the eaglets' feather 'cloaks' to start filling in.
  • Still enclosed in their keratin sheaths, eaglet pinfeathers will grow longer. 
  • We may be treated to the beginning of wingercizing sessions! Once the eaglets can stand, they can really begin exploring their wings. 
By the end of their fourth week, the eaglets could be standing. By the end of their fifth week, they will be standing and could be starting to walk. I have no doubt that many of us will be mouse-clicking, shoeing, and blowing to get inquisitive eaglets back into the center of the nest as they widen their explorations and begin broadening their horizons! We will also see changes in behavior. Although the eaglets continue to compete for food, baby bonking has mostly ceased. This always makes me wonder what functions it serves. We know bonking 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.

While we've been making guesses at gender, the weight of the two sexes begins to separate as females gain weight faster than males.  Sex takes over from age as a size determinant around 50-60 days. But cameras can be tricky and clutches can have large males and small females or be all one sex, making ID impossible without measurements or a genetic test. We'll have a lot of fun seeing if size conforms to our observations based on what we have seen of beak size, commissure extension, and other traits, and I can hardly wait for food tearing and wingercizing!

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 3-4? 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. The nest and eagles always have more to teach us!

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

Monday, April 10, 2017

Eaglet Growth and Development, Week Two

It is April 10 as I write this, and our eaglets are growing rapidly! In Decorah, D26 is 10 days old, D27 is 9 days old and D28 is 6 days old. At Decorah North, DN4 and DN5 are 12 and 11 days old. And at Fort St. Vrain, FSV34 and FSV35 are 15 and 13 days old.

D26. See the earhole?
In their second week of development, the eaglets will gain roughly two pounds between their 7th and 14th day of life. They will experience rapid growth in features like beaks, culmens, and footpads, start replacing their white natal down with thicker grey thermal down, and begin exploring the nest. Although they aren't yet standing on their toes, they are able to sit up - way up! - for feeding and shuffle around on their metatarsi. Their eyes are wide open and fit more comfortably in their eyesockets, features like brow ridges are beginning to appear, and their legs and footpads are yellow, not pink. Gary Bortolotti wrote that bald eagles might gain more weight per day than any other north American bird, although the majority of their weight gain occurs within the first 30-40 days. This rapid weight growth is fueled by their nutrient-rich diet of meat. Over the past week or so, we watched the eaglets chow down on fish, roe (fish eggs), rabbit, squirrel, unidentified birds, and prairie dog. Poop is beginning to streak the poopcasso tree and crib rails as the eaglets become more proficient at shooting poop out of the nestbowl. While babylet battling hasn't entirely subsided, it has become less intense as pecking orders are established and eaglet crops are repeatedly stuffed until they look ready to burst!

Ma provides shade for FSV34 and FSV35
The Fort St. Vrain eaglets are the oldest of the group. Watcher Donna Young wrote that "We have two eaglets that are already quite adventurous. They are moving about the big nest. One climbed up onto the fence rails yesterday, but found its way down too. It may become a true Colorado mountaineer!" This is in line with past years at Fort St. Vrain, where a large nest and warm temperatures seem to lead to earlier wandering. Cold is a challenge to eaglets under 10-15 days of age, but so is heat! With little ability to control body temperature and no way to lose heat except by panting, the eaglets did their best to retire to what little shade tree limbs and the nest itself offered. Ma FSV also provided shade for the eaglets by moving from one to the other and standing between them and the sun.

In the week to come, we can expect (continued) rapid growth in footpads, talons, and legs. Beak growth will rapidly slow as the eaglets' beaks approach adult size and we may see dark juvenile feathers start to sprout from their grey down. Overall weight and height gain will continue, most likely reaching their steepest curves some time this week. By the end of their second week of life, our little bobbleheads at Decorah, Decorah North and Fort St. Vrain will be almost a foot tall! Enjoy eaglet earholes and egg teeth while you still can - their earholes will soon be covered by down and their egg teeth are wearing away.

Let's talk a little bit about 'parenting styles'. Last year, watchers observed that Dad North was less involved in feeding his eaglets directly, although he participated in a lot of bucket brigade feedings. The North eagles didn't tend to stockpile prey and food often seemed scarce at the North nest. Given the differences between Dad Decorah and Dad North, some watchers speculated that Dad North was on his first round of eaglets. While we didn't weigh in on that discussion, we have seen changes this year. The North's nesting chronology moved ahead by almost one month to match that of the Decorah eagles. While Dad North still offers the bucket brigade from time to time, he is participating in more tandem feedings with Mom North. When feeding solo, Dad North often offers food to both eaglets, picks up dropped food and re-offers it, and removes grass from their beaks. Food seems plentiful compared to last year, with fish after fish coming into the nest for DN4 and DN5. Using feeding and food availability as benchmarks, Dad North has undeniably become more skilled at some aspects of eagle parenting. Like flying, parenting is instinctual - but proficiency is learned.

Tandem feeding, Dad and Mom North. Dad North (at left) is feeding DN5. Mom is feeding DN4
As John pointed out, food availability in the nest reflects food availability on the ground. In late March, suckers are spawning, trout are actively feeding on emerging and hatching insects, rabbits and other mammals are leaving their winter dens and grounds (often with young in tow), and flocks of birds are migrating through the area. This rush of food comes at the perfect time for newly hatched eaglets - something Mom and Dad North appear to be taking full advantage of this year! The Fort St. Vrain nest is also piled high with prey, including prairie dog. If the weather stays warm, we might see turtles join the list as streams and smaller water holes shrink. Look for turtle plastrons at the bottom of the Fort St. Vrain nest!

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. 
 I'm not sure how familiar many of you are with the cortical homunculus, an image-based tool that maps tactility. While useful and extremely cool, most cortical homunculii are static - that is, they reflect just one phase (usually adult) of an organism's life. But an eaglet's cortical homunculus will differ from an adult's as body parts and associated skills are gained and neural pathways developed. Our eaglets' brains and bodies are rapidly growing and changing as they gain the skills they need for life outside the egg! I'd tend to think that visual acuity suddenly 'lit up' this week, leading changes in coordination as the eaglets began sitting up and moving around.

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

Friday, March 31, 2017

Why a functioning EPA is important for birds

The EPA, or Environmental Protection Agency, is a US government agency established in 1972 to protect human health and the environment. By the early 1970's, Americans were increasingly aware of the dangers posed by pollution, the indiscriminate dumping of sewage and industrial chemicals, and the widespread and unregulated use of pesticides, herbicides, and other toxic agents. Peregrine falcons, bald eagles, and other birds were critically endangered and at risk of extinction, the Cuyahoga river had famously caught fire several times, Great Lake Erie had been declared dead, and smog regularly blanketed America's largest cities. People were organizing at local, state, and national levels to get ordinances and laws passed to reduce pollution and penalize polluters. In some cases, people were driven by concerns about the future, but in many others - like Los Angeles - they were concerned with immediately improving health and saving lives.

Prior to the Clean Air Act, the Clean Water Act, and the EPA, there were no legal or regulatory federal mechanisms to protect the environment. While communities could address local problems, water and air don't have a fixed address. A regulatory mechanism was needed that would allow enforcement across county and state lines, address pollution on land and waterways owned by the federal government, and provide funds for cleaning up large, extremely toxic messes like this one, which is still affecting the Channel Islands. Following the introduction and passage of several bills related to environmental concerns, President Nixon proposed a new agency on July 9, 1970, to consolidate the environmental responsibilities of the federal government. Congress approved the proposal and President Nixon signed an executive order establishing the EPA on December 2, 1970.

Why does this matter to human health and wildlife? The EPA is able to regulate and enforce environmental and human health laws as related to air (the Clean Air Act and Amendments), water (the Safe Drinking Water Act, the Clean Water Act, the Water Quality Act, and the Safe Drinking Water Amendments), land (the Wilderness Acts, the Wild and Scenic Rivers Act, and the Surface Mining Control and Reclamation Act), endangered species (the Marine Mammal Protection Act, the Endangered Species Act, and the Endangered Species Preservation Act), Hazardous Waste (the Solid Waste Disposal Act, the Resource Recovery Act, and the Hazardous and Solid Wastes Amendments Act) and human health (the Federal Environmental Pesticide Control Act, the Toxic Substances Control Act, the Nuclear Waste Repository Act, and the Food Quality Protection Act). In short, the EPA played a very important role in the cleaner air, the cleaner water, and the formerly endangered species we so enjoy today.

Perhaps most important to bald eagles, peregrine falcons, brown pelicans, and many other birds, the EPA banned DDT in the United States in 1972 based on its adverse environmental effects. But that isn't the only banned chemical that affects birds. Remember DN2's death last year? He was poisoned by methomyl, a member of the carbomate chemical family. Carbofuran, a related chemical, killed millions of birds each year before the EPA canceled it for use on crops in 2009. In 1990, diazinon was classified as a restricted ingredient and banned for use on golf courses and turf farms, marking the first time regulatory action was taken specifically on behalf of birds. It was banned entirely on January 1st of 2005. Chlordane was banned for home, garden and agricultural uses in 1983. It is persistent in the environment and still poisons birds today, but not at the levels it once did. Monocrotophos was removed from use in the United States in 1991, although it was linked to huge die-offs of Swainson's Hawks on their wintering grounds in Argentina. You can read more about the American Bird Conservancy's successful intervention here.

So in short, a working EPA is important for birds because its actions have directly benefited many birds, including eagles and peregrine falcons, and its enforcement of environmental laws has resulted in cleaner air, cleaner water, and better health. Concerned only with the economy? The estimated economic benefit for banning lead ranges from $110 billion to $319 billion for each year's newborns. The yearly economic benefit of that alone is far bigger than the EPA's annual budget.

It is also worth noting that the EPA's national efforts to reduce environmental risk are based on the best available scientific information - one reason why it is concerning that the House voted Wednesday to restrict the kind of scientific studies and data that the Environmental Protection Agency (EPA) can use to justify new regulations. It is hard to make decisions based on science when you can't use science. The 42% reduction proposed by the Trump administration for the EPA's budget ($8.1 billion in 2016, or less than .3% of the entire federal budget) will also make it much harder to conduct research and enforce existing laws. And the decision of EPA head Scott Pruitt to ignore his own agency's research and not ban the pesticide Chlorpyrifos (Lorsban) means that it will continue to poison birds, other wildlife, and human beings for at least the next five years, if not longer.

So what can we do? In the short term, you can contact your Senator and tell them to oppose the HONEST act, which is anything but. It was received in the Senate, read twice, and referred to the Committee on Environment and Public Works on Thursday, March 30th. Here is a helpful place to track the bill and here is another helpful place to track this and other bills. In the long term, you can educate yourself and others about the substances most toxic to birds. You can support organizations that advocate and do research on behalf of birds. Of course I like it when people support the Raptor Resource Project, but you should also take a look at the American Bird Conservancy and the work they do. You can get involved in local projects: remember, our national concern for the environment grew in part out of local issues, whether it was choking smog, the loss of soil, the contamination of water, or the need for local parks and wild land. We can all keep reminding our congressional representatives and senators that conservation and the environment are important to us. And we should all take strength, determination, and resolve from our polluted past: strength, since we have made significant improvements; determination, so we can keep moving forward; and resolve that we won't go back to those days again.

Things that helped me learn and write about this topic:

Keep in mind - we've come a long way, baby!

Eaglet Growth and Development: Week One

We are watching eaglets at three nests right now: Decorah, Decorah North, and Xcel Energy Fort St. Vrain. The oldest (FSV34) is five days old, and we're still waiting for DN6 and all of the Decorah eaglets as I write this. What can we expect in the first week of watching? Weight Gain!

DN4 at the Decorah North Nest
Like humans and other animals, growing nestlings have developmental milestones. The eaglets spend roughly the first week of their life gaining weight. They aren't able to thermoregulate yet, so depending on the weather and temperature, they may spend a lot of time under Mom and Dad. We'll see them eat, sleep, scuffle, and grow stronger as they interact with one another.  They will go from roughly 3.2 ounces - about the weight of 18 nickels - to roughly 16 ounces or one pound, increasing their weight five times over in just seven days.

Weight gain (g/day) as a function of age for male and female nestling Bald Eagles
This chart was reprinted from The Wilson Bulletin 96: 527 from an article published by G. R. Bartolotti (1984) with the written permission of the Wilson Ornithological Society. 
Many structural features, including foot pads, tarsi, and hallux claws, won't start rapid growth until 10-15 days after hatch. But the hatchlings' mid-toes and culmen - the dorsal ridge of the upper mandible - are already growing longer! Food is the root of all else besides, so it isn't surprising that the culmen achieves maximum growth in the first ten days. I suspect that the mid-toe aids balance, a crucial element of sitting up and exploring the nest. While our eaglets won't truly stand on their feet until they are roughly four weeks old, they will begin to shuffle around the nest on their tarsi long before that.

Enjoy the downy bobbleheads this week! By next week, they will already be growing their longer 'wooly' second or thermal down and alternately worrying and thrilling us with their interactions and sojourns around N2B.

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. While thermal down starts growing at about ten days and juvenile flight feathers at about 27 days, 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.

I'm not sure how familiar many of you are with the cortical homunculus, an image-based tool that maps tactility. We discussed it very briefly in this blog and I'll include links below. While useful and extremely cool, most cortical homunculii are static - that is, they reflect just one phase (usually adult) of an organism's life. But an eaglet's cortical homunculus will differ from an adult's as body parts and associated skills are gained and neural pathways developed. Our eaglets' brains and bodies are rapidly growing and changing as they gain the skills they need for life outside the egg!

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

Thursday, March 23, 2017

What's inside those bald eagle eggs?

It is 31 days since egg number one was laid in Decorah, 32 days since egg number one was laid at Decorah North, and 36 days since egg number one was laid in Fort St. Vrain. We are starting hatch watch for Fort St. Vrain on Saturday, Decorah North on Sunday, and Decorah on Monday. The embryonic eagles are either in or approaching their final stages of development now, but what did they look like as they developed and grew inside their eggs?

Dr. Peter Sharpe from the Institute for Wildlife Studies developed a table of bald eagle embryonic development based on work done by Hamburger and Hamilton (1951). While not all bald eagle eggs hatch in 35 days, the stages of development look something like this...

Development of a chick, drawing from Frank Lillie photos. Artist William Sillin
From 0 to 4 days: A single cell is formed by the union of sperm and egg. It divides into multiple cells and forms layers. Head and tail are established, the emerging embryo divides into blocks called somites, and basic life support structures begin to develop, including the nervous system, skin, circulatory system, gastrointestinal system, and optical system.  The embryo turns onto its left side. Its heart begins to beat roughly 72 hours after incubation begins.
Chicken embryo at roughly two days incubation: equivalent to an eagle at about 3.5 days
At four days of age, the embryonic eagle doesn't look anything like a bird, but it has inside and outside layers, it can transport materials through its developing circulatory system, and its nervous system has an anterior-to-posterior template in place. The brain and nervous system will continue to grow and change, but the stage is set for the development of a skeletal system, limbs, a beak and tongue, foot and wing digits, and organs. 

From 3.5 to 9 days: The amnion closes, sealing the developing embryo inside the egg's innermost membrane. The allantois forms to sequester liquid waste and exchange gases through the porous eggshell. Wings, tail, and leg buds form. Eyes develop pigment.  Leg buds grow larger than wing buds and limbs begin to form. Elbow and knee joints are distinct by roughly 8 days and digital grooves - the precursors of toes and wing structures - are distinct by roughly nine days. The embryo's beak and tongue begin to form.
Chicken embryos roughly 23 to 25% of the way to hatch
At nine days, the minute embryonic eagle is about 25% of the way to hatch and still doesn't look especially birdlike. It has a head, eye pigmentation, stiff differentiated limbs, the beginnings of a beak, rudimentary digestive organs, and a defined sex. The stage is set for further organization as the embryo develops an egg tooth, true eyes, and feather germs. 

From 11 to 17 days: The egg tooth and two scleral papillae form on the 11th-12th day. Limbs are bent. Dorsal feather germs form on the 12th day. A nictitating membrane is visible on day 13. Ventral feather germs develop, the eyelids begin closing, and flight feather germs develop. 

A chicken embryo roughly 50% of the way to hatch
At 17.5 days, we are roughly halfway to hatch. Our embryo's head is disproportionately large, but it is definitely a bird. It has a beak, distinct toes, bent limbs, and eyes that take up most of its head. Its eyes and eye cavities aren't done forming and it needs to develop scales, nails, rough pads and spicules, and down feathers. Its yolk sac and small intestines are still outside its body cavity, and it has a lot of growing to do!

From 18 to 23 days: Leg scales, tiny talons, and plantar food pads appear. The eyelids are almost closed and the eyes are no longer quite as large in proportion to the rest of the head.

We are 65% of the way to hatch! Other than the closing of the body cavity, most major morphological changes are done. The eyelids will close, the eyes will grow into their sockets, the eaglet will develop natal down, it will internalize its egg yolk sac, its body cavity will close (leaving behind an egg yolk sac scar) and it will position itself for hatching! 

So what happens right before hatch? Just a few days from external pip, the rapidly growing embryo is taking up nearly all the space in the egg. It...
  • Turns so that its head is at the large end of the egg next to the air space.
  • Pierces the internal membrane - the internal pip - and begins to breathe air with its lungs. Hatch has started!
  • Takes the yolk sac into its body as it consumes most of the remaining albumen and yolk. 
  • Grows enough to contract the hatching muscle, pointing its head up and positioning its egg tooth against the shell of the egg. The eggshell is thinner and weaker than when it was laid, since the growing embryo absorbed calcium from the shell for its bones. 
  • Rubs its egg tooth against the shell, which cuts a small hole. We have an external pip!
  • Rotates its body, slowly cutting a ring around the shell.
  • Pushes its body against the shell, forcing the shell apart.
  • Works itself free of the shell membranes and halves. The eaglet has landed and hatch is complete!
We are looking forward to hatch later this week! Curious about what's in store? Watch this 2015 video of the very final stages of hatch in N2. 

Illustrations were taken from Popular Science Monthly/Volume 71/September 1907/The Problem of Age, Growth and Death III:  Link. Thanks to artist William Sillin for allowing us to use his lovely illustrations: (check it out - his illustrations are very cool!). Also take a look at this cool plate by Keibel and these lovely photos of chicken embryos:

Things that helped me learn about this subject:

Tuesday, March 21, 2017

Body plans and BOP shapes

Since we are watching bald eagles and peregrine falcons, I wanted to talk a little bit about body plans and their influence on flight, hunting, and prey base. As watchers know, eagles are soaring generalist hunters that eat almost anything they can sink their talons into, while peregrine falcons are energetic, acrobatic flyers that specialize in catching birds in the air. Both are birds of prey, but their body plans and wing shapes result in very different lives.

Body plans, size, and flight
With their long, broad, slightly rounded wings, large wing slots, and broad, wedge-shaped tails, bald eagles are built for soaring. They hold their wings flat and save aerial acrobatics for hunting and encounters with other birds. While tail winds and thermals aren’t absolutely necessary for eagle flight, their migration corridors and styles take advantage of both. Thermal winds are powered by sunlight, which means that eagles migrate during the day. They also tend to prefer wind corridors, including ridgelines and funnels that concentrate and amplify wind – think of the cliffs of the Mississippi river or the tight river valleys and ridges of NE Iowa. A stiff tail wind will send migrating eagles aloft in their thousands, especially over surfaces with little opportunity for thermal soaring. The Bald eagle body plan and low-aspect wings - large, broad wings relative to its overall surface area - is most suited to low-angle, low-energy soaring flight.

Unlike bald eagles, Peregrine falcons are built for speed and maneuverability. They have long, narrow, pointed wings and long tails shaped for diving, twisting, and turning in flight. Where eagle flight is flat, peregrines often fly in a series of arcs as they dive, dash and pursue other birds in flight. The peregrine body plan and high-aspect wings - narrow, pointed wings relative to its overall surface area - is most suited to high speed, energetic and often acrobatic powered flight.

Bald eagle silhouette
Peregrine falcon silhouette

Although I don't confuse falcons and bald eagles, I often find body plan and flight style to be very helpful in identifying similarly-sized birds of prey at a distance. Is it large and flying flat, holding its wings in a vee and tilting as it flies, or M-shaped? If you are in northeastern Iowa, the first is probably an eagle, the second is probably a turkey vulture, and the third is probably an osprey. Are the wings large or small in proportion to the rest of the bird? Are its wings pointed or rounded? Is its tail long or wedge-shaped?  Is it flapping and gliding, diving, hovering, or quartering low over a field? Did you see it in the woods or in the open? Body plan, behavior, and habitat are very helpful in identifying birds of prey, especially at a distance.

Silhouettes of birds of prey in flight from
Body plans, hunting, and prey base
In general, all birds of prey have keen vision, talons, and curved beaks to help them hunt, kill, and eat prey. But not all beaks, talons, and hunting styles are the same. The peregrine falcon’s speed and maneuverability makes it uniquely suited to catching birds in flight, while a bald eagle’s size, strength, powerful feet, and long talons make it an excellent generalist hunter. Both birds take full advantage of their very different body plans when it comes to catching and eating prey.

A peregrine's high speed, high angle dive
A bald eagle's lower speed, lower angle flight

A peregrine falcon’s speed and maneuverability allow it to fly high, dive steeply, and hit prey so hard that the force of impact severs its prey’s spinal cord. A peregrine begins its dive by rolling, cupping its wings around its body, and tucking in its feet, yielding an aerodynamic raindrop that slices through the air at high speeds.  Special cone-shaped bones in its nostrils – an adaptation unique to peregrine falcons – allow it to breath while diving at speeds of over 200 miles per hour.  As the falcon approaches its prey, it extends its feet, brakes sharply, and snatches it out of the air with its long, slender toes and sharp talons. If hitting a bird doesn’t kill it, peregrine falcons use their tomial tooth – a special notch in their beaks that bald eagles don’t have – to sever their prey’s spine. While a peregrine’s feet are strong and quick – great for grabbing and slashing attacks – they don’t have the crushing strength of a bald eagle and their diet is largely restricted to other birds. 

A bald eagle’s large size, soaring flight, and strong feet help it to take a wide variety of prey, although its speed of attack is slower, its angle of attack is lower, and it usually kills prey with its feet. As we’ve seen at the fish hatchery, Mom and Dad swoop shallowly over the retaining pond, braking heavily as they plunge their feet into the water and pull out trout. Without stopping, they fly into a tree, on to the bluff, or into the nest, crushing or stabbing the trout with their powerful feet and sharp talons. Although they have special adaptations called spicules – rough bumps that help them grip slippery fish - bald eagles don’t specialize in any one kind of prey, and their size, strength, powerful feet, and fishing ability give them access to an extremely wide prey base.

Again, falcons and eagles are very different and I don't confuse the two, even at a distance. But understanding how body plans influence birds is useful to understanding their lives and identifying them in the field. I find it to be more helpful overall than looking for hard to see features, especially if a bird is far away. 

Hashtag #musing: could body plans impact gregariousness? Off their breeding grounds, bald eagles are quite gregarious. Their flashy colors, large, visible body plans, and wind-seeking behavior often bring them into proximity with other eagles. Eagles compete (think piracy and kleptoparasitism) but they also eat a wide variety of prey and often benefit from following other eagles when searching for food. As far as we know, peregrine falcons are loners. During migration or following dispersal, there can be multiple peregrines in a site with an abundance of food. However, they aren’t gregarious. Perhaps their more solitary behavior is driven in part by a body plan that results in a restricted prey base (leading to serious food competition), no real benefit to stealing or attempting to steal food, and less congregation around important dynamic and thermal soaring points.

Did you know?
A turkey vulture "V" is more correctly referred to as a dihedral. Turkey vultures are masters of soaring without flapping as they ride the wind in search of carrion. How do they do it? As wind strikes one wing or another, tipping the vulture right or left, one wing tips high and the other tips low. Wind flows under the low wing, pushing the vulture and righting it until it tips again. This allows them to exploit the smallest of air currents as they soar lowly and slowly through the sky. While they sacrifice some maneuverability, their food - carrion - doesn't require agility to catch.

Harriers also engage in dihedral flight, but their food - small mammals, reptiles, amphibians, and birds - requires considerably more agility. Compare their body plan with that of a turkey vulture. Dihedral flight allows them to soar very slow and very low, but they have a long tail and wings more like a falcon, which helps them roll and twist when needed. Harriers are a very interesting bird of prey: visit Cornell's website to learn more about them!

And finally, I've seen some interesting conundrums when people compare birds to aircraft. Remember that aircraft can't change their shape to respond to wind conditions or the need to rapidly change position. But birds can and often do change shape as they fly! I chose silhouettes that I thought best represented each bird overall, but birds might adopt different flying styles under different conditions, even if they can't change their overall body plan.

Things that helped me learn about this topic

Monday, March 20, 2017

Message from the Director

It has been a busy start to the year, but it has been productive and very enjoyable.  A warm welcome to our teachers and classrooms that are following along!  We have been working hard to get raptor cams ready for nesting season, training volunteers to operate them, and telling the interesting stories as we watch nature unfold and enter a new cycle of life.  If you are an educator and would like a classroom account, please visit

Two stories come to mind….the first one as each day starts is how to best share the raw beauty that comes with viewing our Decorah Eagles and other raptors as they do what comes naturally.  We are drawn to that connection with the natural world they represent.  Who could imagine that we would recently watch and wonder about the first vivid footage we have seen of Mom North vocalizing while sleeping and dreaming [video:]!  I also had to hunt down the video footage captured by our videographers when I heard about the confrontation between the first female peregrine falcon to arrive at Great Spirit Bluff with our resident female Michelle as she returned a week later to claim her nest and mate. It was not too rough, but I can honestly say I was rooting for Michelle and had to laugh as some of you joked about Newman having some explaining to do! [video:]

The second story is what a difference we can make by leading as an example and using our energy and talents to advocate for the raptors and nature around us.  Most of us have been touched by the example set by Bob Anderson and his RRP partners in raptor conservation and research.  It has been a time of reflection to watch the recent Iowa Public Television movie (The Eagles of Decorah) about the discovery of the Decorah Eagles and subsequent production of the movie “American Eagle”.  It is that passion that has brought us all together to carry on.

Our second annual fundraiser at the Celtic Junction in St. Paul was an event to remember and served as a kick-start to the year.  It was a donation of time and musical talent, one of the many you share, showcasing contributions that help us fulfill our mission.  This year we are focusing some of those efforts on kestrels, osprey, and telling stories of the unique Driftless Area.  I can’t wait to share our first newsletter with you all soon!  We now prepare to monitor peregrine falcons as they return to their historic bluff eyries.

There are exciting times ahead watching and experiencing Nature’s reality TV and sharing our love for the raptors who are only part of the bigger picture.  Spring is just around the corner and we have some exciting projects to share that are in process….stay tuned and need I remind us all to get outside and capture the outdoor experience! It won't be long until eggs start hatching!

John Howe
Director, Raptor Resource Project

Thursday, March 09, 2017

Sweet Eagle Dreams

Do bald eagles dream? Some footage of Mom North had us discussing the question today. In the video, Mom North appears deeply asleep, with her head tucked underneath her wing. At eleven seconds, she starts to stir. Still tucked in, she starts to vocalize. She stops, stirring very briefly at 50 seconds before settling back down. The behavior appears remarkably similar to the dreamy stirrings of slumbering dogs, who quiver, twitch, ‘run’, and even growl in their sleep.

A study on sleeping finches found that their sleep is quite complex. The slumbering finches experienced slow wave sleep (SWS), rapid eye movement sleep (REM), intermediate sleep (IS), and K-complex sleep, which aids memory consolidation in human beings.  REM episodes were brief early in the night but became longer as REM density increased and intervals between REM sleep decreased. Unihemispheric sleep (sleep with one eye open) was less common, of a shorter duration, and almost exclusively restricted to the light phase of sleep: think napping over deep sleep (“I’m not sleeping, I’m just resting my eyes!”).

Why is complex sleep important? Bird brains don’t look a whole lot like our brains. Given the lack of structures like a neocortex, human researchers have tended to assume that birds aren’t capable of complex neurological activity, including dreaming. But studies like this show that birds are much more complicated and intelligent than we think. The ethology of crows (and some other birds) has proven that birds have a sense of past and future, which allows them to plan, change and weigh consequences, and refrain from unproductive actions. Some of this stored information is replayed while sleeping, which may help birds develop memories, practice daily activities, or process events. So what were the zebra finches dreaming about? The same study found that the sleeping finches replayed, rehearsed, and perhaps improvised songs in their sleep. In short, songbirds – at least these songbirds – dreamed of singing.

Do eagles experience complex sleep? We don't know, although the authors of the zebra finch study state that there could exist a greater complexity to sleep structure across bird species than has commonly been recognized.  Eagles experience many of the behaviors we see in birds like crows, which are renowned for their intelligence: language, delinquency, insight, emotion, frolic, passion, wrath, risk taking and awareness. Eagles organize in social multi-age groups away from their territories, follow consistent migration paths between winter and summer grounds, select and retain mates, build large, complex nests, incubate and brood young in challenging conditions, teach their young, learn from life events, and recognize and remember things on their territories. They clearly have intellect, even if it isn’t organized much like our intellect, and they most likely experience complex sleep. Perhaps our question should be not "Do eagles dream?" but rather, "What do eagles dream about?".

We reached out to Marge Gibson from the Raptor Education Group, who responded that her birds (a macaw, doves, and a turkey) dream and vocalize while dreaming. Several forums on pet birds, especially Psittaciformes, discuss dreaming in birds, although I wasn't able to find many videos of the behavior. 

Things that helped me learn about sleep in birds:

Bonus fun!
This blog addressed primarily avian dreaming, but avian sleep is an interesting topic and we'll return to it in another blog!

Tuesday, February 28, 2017

I can't chat on eagles!

People using Chrome may be experiencing some difficulty when trying to chat on no matter what you do with plug-ins, the chat tells you that you need to enable Flash to chat. This is frustrating, since you have enabled Flash in at least three different ways!

Chrome55 now disables Flash by default. Try this step to get it working on ustream:

  • Open a tab in Chrome and type in chrome://flags/#prefer-html-over-flash
  • Change the Run all Flash content when Flash setting is set to “allow” dropdown to ‘Enabled’.
  • Press the Relaunch Browser button.
Click to enlargen

Oddly enough, we don't have to do this for the chat on our website, even though it is a plug-in from Ustream. On our website ( setting a rule to allow Flash to run on http://www, is enough to make it work.

More about plug-in issues can be found here: We hope to have an HTML5 version of the chat from Ustream soon.

Tuesday, February 21, 2017

Please donate to the Raptor Resource Project!

What does the Raptor Resource Project do? We are a 501c3 that specializes in the preservation of falcons, eagles, ospreys, hawks, and owls. In addition to bringing you the Decorah Eagles, Great Spirit Bluff Falcons, and other birds of prey, we create, improve, and directly maintain over 50 nests and nest sites, provide training in nest site creation and management, and develop innovations in nest site management and viewing that bring people closer to the natural world. Our mission is to preserve and strengthen raptor populations, expand participation in raptor preservation, and help foster the next generation of preservationists.

As a nonprofit environmental organization, we depend on donors, research, and our other programs for our entire budget. With your tax deductible contribution to the Raptor Resource Project, we can:
  • Continue updating to high definition digital cameras in Decorah and elsewhere.
  • Provide one of the world’s largest public wildlife education programs to countless classrooms through our unequaled Ustream channels, interactive chats, facebook page, and blog.
  • Reboot our kestrel nestbox program. In addition to placing boxes, we plan to monitor, band, and report on kestrel populations as part of the American Kestrel Partnership. Eden Prairie Girl Scout Troop 14286 is providing 12 boxes for installation this year. 
  • Begin a diurnal raptor banding and observation station. Master bander and board member Dave Kester will be in charge of this effort and he is raring to go!
  • Partner with landowners, private businesses, and government agencies to monitor and band peregrine falcons at over 40 sites. This year we plan to add collection and identification of prey and prey remains to our work.
These things all take money. We have $188,700 budgeted for 2017. Our expenses look like this:
  • Staff and contracts: $130,000. This includes salaries and compensation for camera installations, maintenance, and climbers for camera work and banding. Since September of 2016, we have had four major installation projects: one at Decorah, one at Decorah North, one at Fort St. Vrain, and one at Xcel Energy's Allen S. King plant in Oak Park Heights, MN. Our falcon surveys will start later this week, weather permitting. 
  • Camera-related expenses: $40,500. This includes our new HD cameras, internet access, computers, video archiving equipment, and related supplies: installation and cable tools and hardware, cable, encoders, software, lumber, solar panels, wireless radios, and all non-staff or contract costs related to purchasing and installing camera systems. 
  • Research-related expenses: $9,000. This includes transmitters, trapping supplies, and data costs, climbing equipment, banding equipment, bands, spotting scopes. permits, and autopsies. We also set some money aside to run a diurnal raptor banding and observation station. 
  • Other/Miscellaneous costs: $9,000. This category includes gasoline, electricity, travel-related costs, equipment fabrication, and propane so we can heat the shed!

Our income is generated primarily by donations from viewers of our various cams, and we sincerely appreciate your generosity and support of the Raptor Resource Project mission. Would you please help us make a difference with your donation? You can donate via Paypal by following this link or mail a check to:

The Raptor Resource Project
PO Box 16
Decorah, IA 52101

Thank you so much for your support and we hope you enjoy watching in 2017!

Monday, February 20, 2017

Did we have a new eagle at the Decorah North nest last year?

Mom North rolling her egg
Hashtag this one #speculation! As Decorah North fans know, we had our first egg in that nest on March 11 in 2016. In 2017, first-egg timing retreated to February 19 - earlier than Mom and Dad Decorah! Why did it change so much?

Mom and Dad Decorah's first egg history looks like this:
  • 2/18/16: First egg
  • 2/18/15: First egg
  • 2/23/14: First egg
  • 2/17/12: First egg
  • 2/23/11: First egg
  • 2/25/10: First egg
  • 3/02/09: First egg
  • 3/08/08: First egg (note: this date is an estimation based on a photo of first hatch)
We know that Mom was laying for the first time in 2008. While we don't see a dramatic shift backwards, the first time she laid an egg also marked the latest time she laid an egg. Her nesting chronology slowly shifted earlier, yielding an average first-egg date on February 19 to date. 

Fort St. Vrain's first egg history looks like this:
  • 02/14/17: First egg
  • 02/16/17: First egg
  • 02/14/15: First egg
  • 02/21/14: First egg
  • 02/17/13: First egg
  • 02/16/12: First egg
  • 02/16/11: First egg
  • 02/14/10: First egg
  • 02/17/09: First egg
  • 02/27/08: First egg
  • 03/03/07: First egg
  • 02/17/06: First egg
Note that I didn't say Mom and Dad Fort St. Vrain's egg history. Looking at first egg dates, it appears we had a mate changeover in 2007, although we don't know whether it was Mom or Dad. As we saw in Decorah, nesting chronology slowly shifted earlier, yielding an average first lay date of February 15 to date.

How do peregrine falcons compare? Falcon nests experience a lot more turnover than any of the bald eagle nests we watch, making it difficult to develop data on partner nesting chronologies. For example, we've seen 11 mate changeovers in the 19 years we've banded at Xcel Energy's Blackdog plant in Eagan, MN. However, we can draw a couple of broad conclusions: 
  • A change-over in the resident male or female falcon is often (but not always) accompanied by a change in nesting chronology. 
  • Nesting chronology is somewhat more likely to move later in the first year of partnership and than move earlier as partners are paired over multiple years. 
  • Return timing and territorial fighting both appear to influence nesting chronology, and territorial fighting is one factor in shifting egg-timing later. If a gravid female falcon is killed by an invading female falcon, the resident male will need to court her and fertilize her eggs, moving the nest's chronology later for at least the first year. 
A lot of people speculated that Dad North was new on site last year. While we don't know for sure, the remarkable shift in first egg timing indicates that one of the parents - possibly Dad North - was new. We don't know whether territorial interaction played a role, and we also don't know whether a new male could impact timing differently than a new female. But we will move egg-watch for Decorah North earlier next year. Will we also see a difference in parenting styles and outcomes in the North nest this year? We look forward to finding out!

Note: The Eagle Valley Eagles laid later in the one year we were able to watch them. I wish we could have had at least a few more years to take a look at their nesting chronologies as well, since some of their behavior and provisioning seemed more like what we experienced in the North Nest last year than in the Decorah nest since 2010.

Thursday, February 16, 2017

What is a Brood Patch?

Debbie Fulton from the Fort St. Vrain Eagle fan group got this excellent capture of a brood patch while Mom did a little sunbathing yesterday! Feathers are great insulators, but unsuitable for transferring heat. Shortly before eagles lay eggs, the hormone oestrogen plus a secondary hormone (prolactin or progesterone) causes feathers on birds' bellies to loosen and drop off, creating a patch of bare skin. Oestrogen also controls the development of supplemental blood vessels that bring warm blood close to the surface of the skin, further aiding heat transfer. The brood patch helps eagles incubate eggs even in the coldest weather (a memorable -50F/-45C when egg #2 was laid in Decorah in 2014)!

In precocial birds, feathers begin growing back as soon as the eggs hatch. In altricial birds (including bald eagles), patches remain functional through early brooding (my guess would be 15-20 days, or about the time some of Mom's lethargy starts to fade). Then they gradually disappear, restoring the area to non-breeding function and feather cover about the time the young are fledged.

Why do eagles sunbathe? We believe it helps kill and/or prevent parasites in less-exposed areas like wingpits, and it also looks quite comfortable. Thanks for the great capture!


Wednesday, February 15, 2017

Endangered Species Act and Environmental Laws in Front of Committees This Week

There are at least two important hearings on Capital Hill this week for those who love wildlife and wildlands.

At 10am eastern time on Wednesday February 15, the Senate Committee on Environment and Public Works will hold a hearing entitled “Oversight: Modernization of the Endangered Species Act.” Information about the panel can be found here: We are watching this issue closely. Although bald eagles and peregrine falcons are no longer endangered, they were nearly extinct by the time the ESA was passed and benefited greatly from its protections. We welcome changes that strengthen the Act, especially given the overwhelming evidence for its success, but at least some of the suggested changes seem to be less about improvement and more about rollback. For more about the ESA, read this blog.

On Thursday, the House Energy and Commerce Committee's environment subpanel will look at modernizing the environmental laws under its jurisdiction, including the Clean Air Act and the brownfields provisions of the Comprehensive Environmental Response, Compensation, and Liability Act. Information about that panel can be found here: Many species, not least of all humans, benefit from laws that protect air and water. We have come a long way since Lake Erie was dead, some rivers in the United States regularly caught fire, and smog was fatal. We welcome changes that strengthen environmental, but doubt the panel is truly interested in doing so.

If you follow us and are concerned about these issues, we encourage you to follow the American Bird Conservancy, which is deeply involved in protection for birds on all sorts of levels (including wind turbines, something we get a lot of questions about): We also follow the Teddy Roosevelt Conservation Society, a non-profit hunting conservation organization that is deeply involved in expanding CRP and preserving public land:

Monday, February 13, 2017

Who is that eagle with a transmitter?

We started to get reports in January of an eagle with a transmitter near Lock and Dam 14, which stretches across the Mississippi river between Le Claire, Iowa and Hampton, Illinois. Like most large lock and dam systems, LD 14 has open water even in the coldest weather, making it a popular place for wintering bald eagles. Of course wintering bald eagles attract photographers, and some of those photographers noticed that one of the eagles had a transmitter on its back. Could this be D1?

Bald Eagle ACE, photo credit Ted Thousand
A few things about the eagle: it was a mature adult, its backpack had no antenna and a clearly visible ID number, and it was left leg-banded. Our transmitters have an antenna and Brett tends to band the right leg, not the left (he made an exception for D25 this year in the service of easy ID). Brett suggested I talk with the Rock Island Fish and Wildlife Service to see if they knew anything about it. Bingo - they did!

Sara Schmueker is a USFWS biologist. She told me that mystery eagle #35959 is part of a Midwest Bald Eagle telemetry study conducted by the U.S. Fish and Wildlife Service, West Virginia University, and U.S. Geological Survey.  He is nicknamed "ACE" because he was caught right outside the Army Corps of Engineers - Mississippi River Project Office below Lock and Dam 14 in January of 2016, when he was six years old. ACE summers up in Ontario, Canada - not too far from some of the eagles Brett is studying - and winters at LD 14. Let's take a look at his map!

ACE's Travel Map
Two things stood out for me. Firstly, ACE's trip through Wisconsin is remarkably similar to some of D1's trips and fits the model we proposed here: Secondly, ACE's trip appears to have brought him near to the North Nest area, if not exactly at the nest. Sara told me that around 30 eagles are currently carrying units for this study. Had some of them gotten even closer? I decided to check the study's web page at to find out!

The answer to the first question was 'Yes'! Several eagles had passed directly through the area of the North Nest, which is a sort of bottleneck for eagles on the west side of the river, based on the map. I was also amazed by the flights of what I am going to call the Yellow and Blue eagles, which flew from East Central Iowa all the way up through Nunavut to the Beaufort Sea. According to Google Earth, this is a straight-line distance of over 1800 miles - and neither of these eagles flew in a straight line! And finally, a few of these eagles appear to have passed by Eagle Valley on the east side of the river. I like to think that Brett could have spotted them on one of his observational trips, even if he didn't see their transmitters.

Sara told me that team has an end goal of 50 or more eagles with transmitters, which will each provide about five to six years of data to inform management and conservation of the species. Their partners include some names that will be familiar to our followers: the American Eagle Foundation, Alcoa, ITC Transmission, MidAmerican Energy, the Avian Power Line Interaction Committee, the American Wind and Wildlife Institute, FWS, WVU foundation, and the Peregrine Fund. This is a fascinating project and I really encourage people to go to the FWS website to learn more about it. Again, the address is

A huge thanks to everyone who contacted us about this eagle - it was very interesting to learn about and helped make some great connections! Another huge thanks to Sara Schmueker for her study and the information she provided. Bob would have found this absolutely fascinating. Please stay safe, D24 - we want to know what you do this summer!

We suspect that some people are wondering why our platforms use antenna given that ACE's platform doesn't have one. While we don't have details for all of the eagles in the FWS study, ACE is wearing a cellular platform that uses the same spectrum a cellular phone does. Our eagles are wearing satellite platforms that use a different spectrum, as described here: There are advantages and disadvantages to each system: the cellular platform doesn't require an antenna, but only provides data in areas that have a cellular connection. The satellite platform provides data from everywhere, but requires an antenna. We are continuing to research tracking technology as the technology advances so we can make the best decisions for the health and safety of our bald eagles. 

Friday, February 10, 2017

The Diction-Aerie!

We'll get to the fun stuff pretty quickly, but I wanted to write a quick note on abbreviations. Why do we call the active Decorah eagles nest N2B? What in the world is DN1? Do other nests use the same nomenclature?

In general, we use nomenclature to label eagles and nests. In Decorah, our first nest was never online and was not included in the initial nest count. Mom and Dad occupied N1 from the fall of 2007 to the summer of 2012. In the fall of 2012, they began building N2. They lived in N2 from the fall of 2012 to the summer of 2015, when N2 fell in a storm. If we were following the rules, we would have named the nest we built for them N3 (since three follows two) or N4 (since it is the fourth nest on their territory). But since Bob had just passed away, we named it N2B in his honor. Mom and Dad North are on DNN3, or the third nest built in the Decorah North territory.

Eaglets are given a territorial signifier and long count number. This makes it easy for us to differentiate between our nests and reminds of us of how many eagles have been produced at each territory. Unhatched eggs are not counted. Young that die in the nest are counted. So:
  • The first eaglet to hatch in Decorah this year will be D26 (the 26th eaglet produced by Mom and Dad Decorah).
  • The first eaglet to hatch at Decorah North this year will be DN4 (the 4th eaglet produced by Mom and Dad North since we started counting, and possibly the 4th, period).
  • The first eaglet to hatch at Fort St. Vrain this year will be FSV34 (the 34th eaglet produced on this territory, although it appears we had at least one female turnover).
Other nests may or may not use the same nomenclature system. If the moderators use names, they probably don't. But if the moderators use numbers, the numbers are indicating a count of nests, eaglets, and/or adults. Names like D26, E9, and M15 provide context and information once you know how to read them! And now for the fun...

Presenting....The Diction-Aerie!
With Eggstraordinary Graditude to chatters, and many other EAs who contributed to our eggspanding vocabulary of Eagle-ese / Eaglish we proudly present the Decorah Eagles Diction-Aerie for you to print out, mantle over, and devour the knowledge presented by the Fledge-U-Ating Eagle 101 Classes of 2011-2016. A huge thanks to Sherri Elliott, who posted this for the first time in 2011, and has kept it up to date ever since!

Air-obics - Extending wings and catching a bit of air.
Anthropomorphism - projecting human characteristics onto animals.
Apteria - area on breast with no feathers; aka -brood patch.
Babylets – The fuzzball stage of baby eyas.
Balloon Mantle - a puffball of feathers exhibited by E3.
Bantling – A baby mantle … not a full juvenile mantle yet – coined by ElfRuler.
Beak-A-Boo – D14’s beak was often the only thing seen from his hiding spot.
Beak Bonk - depending on level of intensity can be a slight bump to a sibling or a one-two lead up to a TKO.
Beak Geeks - a term for people who avidly watch the eagles everyday!
Beak Kisses - ahh, one of our favorite spectator sports.
Beak Lips -  area of beak sides to corner of mouth.
Beak Off - eaglet beak joust.
Beakering - sibling disagreements.
Beakathon – 3-Way Beak contest of power.
Beakdown – A beak squabble resulting in a take down of a sibling.
Beakoff - eaglets fake fighting with their beaks.
Bedreagled Eaglets - raggedy look after bad weather.
Benihana Dad – aka Bunnihana Dad – No one can defurr and slice and dice better than Dad!
Big Gulp Protein Smoothies - swallowing a whole fish.
Bird Nerds -  another term for people who avidly watch the eagles everyday!
Birshimi - mystery prey of the bird variety.
Bling - unidentified accouterments brought to the nest from Nest Depot - usually brightly colored.
Bobbleheads - self explanatory, but especially adorable dressed in fuzzy white natal down.
Branch Office  -  Mom & Dad spend most of their time in this space adjoining the nest after the eaglets grow into juvies.
Branching - eaglets hopping from one branch to another prior to fledging.
Breakfish -  first meal of the day that is fish.
BreakFur – the first meal of the day that is furry.
Cameraflague – D14 was expert at hiding above the camera and cables.
Cameritisi Permanentitis Bugitis -  bug on camera lens, also known as camera bugs.
Camming – jumping on the camera.
Cere -  fleshy, membranous covering of the base of the upper mandible.
Claw Floss - name given to Pinky, the baling twine. from 2011.
Chef's Surprise - When eagle bodies obscure the meal being served.
Chicken of the Tree – not tuna … squirrel served in the Cottonwood.
Chicklet - affectionate name for our hatchlings ... see also Babylet.
Circe du EEEaglee’ – Feats of aerobic performance (or feets).
Cleaning Coma - behavior emulating Dad’s cleaning skills, but generally tiring quickly, lapsing into face plant.
Clown Clomp - comical eaglet first steps learning how to walk.
Clown Feet - oversized feet/talons that the eaglets haven't grown into yet, nor know what to do with.
Clutch - total number of eggs laid, or birds hatched during a single nesting period.
Convocation - group of eagles in tree or on ground.
Corn Husk - outer dried corn covering coveted in nest.
Corn Husk Pillow - said item used as head rest.
Corn Stalk - building material for nest crib rails.
Clutch - number of eggs laid in a nest.
Crittergetter – Mom & Dad’s wings used when combating an intruder.
Crop - area in neck where food gathers first before entering stomach if it is full.
Crop Plop - aka Crop Flop - falling over or laying down, usually proceeded by a food coma.
Crop Prop - the ability to use the enormous crop to prop up a bobblehead.
Crop rotation - food moving from the crop to the stomach for digestion (and filling up again).
Cuddle Huddle - all the e's close together for safety/warmth in a group.
Cuddle Puddle - horizontal E cuddle sprawl.
Cuddlelet  - one hatchling all cuddled up by itself.
DDD-ia Pets - just add water to little eaglets.
Decorah - the idyllic location in Iowa where our family set up its Home-Tweet-Home.
DecorahLand - A magical place at the top of a Cottonwood Tree.
Decorah Drop - nap flop.
Decorah Front Porch - our place to watch the EEeee's.
Decorah Shimmy - back and forth motion that Mom/Dad use to position themselves over the eggs/eaglets.
Decorahating - beautification of the nest.
EA'S - Eagle Addicts, aka: Eagle-holics.
E-Bots – hatchlings more ambulatory at age 4+weeks.
E-ddicts - those who watch eaglets and stay in pajamas all day.
E-Gulp - swallowing food whole.
E-Heap - pile of eaglets.
E-Lump - same as cuddle huddle.
E-Pology - Submission bow or another act of 'sorry' after a sibling altercation.
E-Team - long suffering worrywarts who love eaglets.
E-Ticket Ride - the Decorah Eaglet antics are the ultimate ticket to fun in DecorahLand.
EEE-Mail - self explanatory.
E.N.S. - Empty Nest Syndrome
EWOT - Eaglet Without Transmitter (believed to be D18 from  2014).
EWT - Eaglet With Transmitter (believed to be D19 from 2014), now known as Four.
Eagle Condo - eagles in penthouse, smaller birds in lower stories.
Eagle Kneivel - daredevil or showoff behavior.
Eagle Time - no time that has anything to do with human time.
Eagleholics Anonymous -12 step recovery program for eagle addiction.
Eagleholics - (Eagle-holics) people that are avidly watching them daily.
Eagleology – online camera course in eagle watching.
Eaglestock/Eaglefest - 300+ million viewers united on web cam broadcast.
Eagle-ese - our unique vocabulary, also known as Eaglish.
Eagleibrium - balance achieved only by eagle walking.
Eaglemaniacs - people who eat, drink and sleep eagles, with not much real sleep actually occurring.
Eagleicious Delicious - any delightful E behavior.
Eagletecture - construction skills used by Dad to create the nest.
Eagletude - any display of eagle attitude.
Eaglish - all the words we made up for this dictionary.
Eagulp - swallowing food whole.
Ealergies - involuntary sneezing reaction.
Eeelie Button – D14 gave us the first view of the protuberance at belly of the outtie left from yolk sac cord.
EEElympics - athletic feats of prowess.
EEEnsane - an affliction of most Eagleholics.
Eggnant - Mom's condition prior to egg lay.
Elebenty Billion – an enormous number .. coined by our ElfRuler.
Ellergy – eaglet sneezesEyas – eagle hatchlings
Eyas stage - fresh from nest.
Face Plant - off balance eaglet plopping into nest face first, perhaps going into food coma.
Feaking - cleaning a beak on a stick or branch.
Feathairdresser - wind redecorating Mom's hair.
Featherline  - the eee’s hairline feather growth giving them distinguishable identifiers.
Fish Fledge - result of food fight when intended meal accidentally goes off the nest bowl.
Fish Flops - any of the EEeee's wearing a skewered fish are said to be wearing fish flops.
Fishapalooza - a buffet bounty consisting of 4 or more fish brought to the nest in rapid succession.
Fishereagle - Dad, Dad, Dad!
Fishcicles - a serving of frozen fish nestovers.
Fjerky - fish jerky
Flap Mob – siblings rushing to mantle over new food item brought in.
Flapadoodle - Amusing flurry of wing flaps performed by Mom or Dad while sitting (incubating) the eggs.  Generally occurs in middle of night and scares the heck out of everyone watching.
Flappathon - endurance contest of eee 's getting pumped up.
Flatabit – aka Goodyear Rabbit – unmistakable steel belted rabbit roadkill.
Fleaping - flapping & leaping - aka hoppersizing
Fledge - taking the leap from branches to the air of the big beyond.
Fledge Fest - gathering of Eagleholics making road trips to witness fledging.
Fluffles – new tail feathers emerging in a ruffle pattern.
Fly-By - parent checking in, but not landing, and with or without food.
Fly-By-Fake-Out - parent flying by with food to lure E's out of nest.
Flying monkeys - teenlets similarity when wingersizing to the Wizard of Oz flying army. Hum the song: oh weeee oh...ohhhh oh when seeing this behavior.
Food Coma - state of suspension E's go into after eating too much.
Food Fledge – result of food falling/ going overboard from nest.
FOUR - our 3rd transmittered eaglet (believed to be D19 from 2014).
Fret of chatters - a group of chatters worried about the eagles.
Flapping Jacks - eaglets exercizing their wings.
Flash Chat – If something important happens on the nest, there is an immediate convocation of chatters and mods to discuss and view.
Fledge - when the juveniles are ready to leave the natal nest.  Unforunately, Eagleholics are unable to due the same.
Fledge-U-Ation - eaglets graduate to fledging.
Fritching - itching new emerging feathers.
Full-Feathered - a loving way to describe Mom Decorah's 'plus size'.
G.F.Z. - gnat free zone -- a mythical place in Decorah.
Gnat - larger than noseeums and especially fond of the eagle's head area resulting in eagle neck jerk twitching.
Gnat Gnat - a term of endearment used interchangeably for nite nite by EAs.
Gnat Off - miracle deterrent for gnasty gnats.
Gnat Scat Boogie – the eee’s headtwich dance.
Gnatercizing - shaking off the gnats.
Goodyear Rabbit – flat rabbit road kill.
Grub Buddy – sibling feeding food to another sibling … D11 did this often to its siblings.
Guest Nest - aka N1 as when FOUR (believed to be D19 from 2014) took over N1.  Kind of like having your kid move out ... but to the detached garage.
Guy-liner - one way to identify Dad is black liner around his eyes.
Hallux - rear locking talon, also known as eagle thumb.
Hard Penned - feathers firmly attached to bone.
Home-Tweet-Home – The nest.
Homeland Seggurity - mythical agency in charge of nest enforcement rules and regulations.
Hoo-Coos - soft little vocals from the eaglets.
Hoppersizing - up and down movement, usually in conjunction with wingersizing.
Hop-Squash - exhuberent nest hop resulting in a sibling step on. Usually E2 gets hop-squashed.
Hoppiness - what else would you do after a good feed and found you had wings?
Hover Mantle - mantling behavior parallel to the prey of the day.
Hovering - catching air with outspread wings while staying in a fluttering suspended motion.
Hugbrella - wingstretch from one e to another.
Kettle - group of eagles in the air.
JuvEEE's - our beloved eee 's and ddd 's just before ready to fledge.
JuvEEE Court – Justice of the Peeece presided over the matter of D14 allegedly dislodging a cam mount screw and breaking the cam on Trunk Tower in 2012.  The case against the daredevil was thrown out by the EEE-Pellet Court and the darling was eeequitted.
Juvie Jump – another name for the game of leap eaglet.
Juvie sprawl - juveniles taking up extra nest space spreading wings out while napping.
King of Mulch Mountain - EWOT (believed to be D18 from 2014) defending city mulch pile, aka N3.
Leap Eagle - hopping over a sibling.
LEGO Eagle - pixilated image of our eagles.
Lumpasizing - E's staying close together or sleeping in a pile.
MODA - new acronym for is it Mom or Dad when a very rainy 2014 day prevented a positive ID by chatters and mods.
M.O.D.S  - Master Ornithological Data Searchers; also gatekeepers of the RRP FB page or chat.
Mantle - The action of a bird spreading its wings, fanning the tail & arching over prey, to hide it from other predators, including other birds or siblings. From Old English/Norse for cloak. (E3 delighted us with several distinct mantles: Balloon Mantle and Ninja Mantle).
Mantle Fluff ... not a mantle, not a bantle, but a puff of the feathers to intimidate and claim first noted by D18 at 6 weeks old.
Master Mantler - E3 showed extraordinary mantle diversity.
Mest – the nest in disarray from active juveee’s.
Moist Fowlettes - wet eaglets.
Momblock – Mom’s windbarrier for the babies.
Mombrella - Mom covering her eaglets with her wings, mostly in inclemate weather. (see also poptent).
Moonwalk - backup walk prior to a poop shoot.
Mousepad – off-season nest at night turns into a mouse pad.
Mulch Mountain - City of Decorah's mulch pile site.  It's where D18 was found a week after his fledge.  Also the place where D19 (EWT) (FOUR) was relocated to be with her sibling.  AKA N3 (Nest 3).
Muskrat jerky - poor thing which gets picked on by the eee’s when unearthed from the nest.
N1 – the original Cottonwood nest used from 2007/08 thru 2012.
N2 – the New Nest, aka: Yonder Nest used in 2013 and 2014. Subsequently destroyed 7-18-15 after a microburst toppled the top 20ft of nest tree.
N2B - (in Bob's memory = N2Bob) starter, human-built nest constructed and installed in a cottonwood tree just 75ft from the former N2 site, and has been adopted by Mom and Dad Decorah for the 2016 season.
N3 - temporary mulch pile nest taken over by EWT & EWOT in 2014.
N.W.Z - the state of zen Eagleholics try to remain in during each season.
Name That Prey - a favorite chat game of guessing what prey has just bee brought in by the P's.
Nare - nostril holes on the beak.
Neck Biter - D19 from 2014 wasn't a beak bonker as much as she was a back of the neck biter.
Nest Depot - wherever Mom & Dad can find new decor for the nest; ie- horsehair, corn husks, branches, straw.
NestFlix - the nightly video round-up.
Nest Bowl - the deeply insulated vault within the nest that corrals eggs and/or hatchlings.
Nest Guests - anyone watching the UStream video.
Nest Potatoes - eagles lazily lounging, usually after eating.
Nestcapades – any eee antics of a comedy nature.
Nestflix – the videos taken during the day of our famileee.
Nesterpiece Theatre – after dinner play antics .. sometimes accompanied by a food free for all.
Nestication - staying put in nest or branches; too relaxed to pack and fly off.
Nestogarbage - nest garbage or debris.
Nestoration - The act of rearranging or redecorating the nest.
Nestovers - uneaten food found in the nest.
Netiquette - a level of decorum expected on Decorah RRP Facebook page.
Nictitating Membrane - transparent inner eyelid, also known as the third eyelid protecting the eye.
Numb Butt - affliction caused by sitting at the computer too long.
Ninja Mantle -  heightened Zen-Like state of mantle & hover (first exhibited by E3 on 5-29-11).
O.C.N.D. – Obsessive Compulsive Nestoration Disorder.
Obstacle Occlusion - varying perspectives of the reality of the nest.
Outstinkt - eaglets knowing instinctively to PS out of the nest.
Owl - urban legendary creature purported to have attacked eagle nest; totally mythical.
P.I.P. – People In Panic waiting for impending pip.
PS - poop shoot - evacuation of the bowels.
Pancake - flat eagle in sleeping position.
Pantaloons - feathered leg eaglet britches.
Pantree – the nest storage locker where extra food is stowed.
Peaglets – piggy little eaglets clamoring for food.
Pet Pillow - using your sibling as something to rest a part of your body on.
Pffffftt! - the distinct sound coming from a PS.
Pickup Stalks - eaglet version of child's game played with cornstalks.
Pinky - the name given to the pink/red bailing twine brought into the nest that inadvertently wound around E2 (D1’s) foot in 2011.
Pip Squeek - a new emerging hatchling.
Pipping Toms – Eaglholics watching for pipping to start.
Pole Dance – D14’s wiggles on the Trunk Tower in front of the camera.
Piscivore - fish eater.
Poop Art - original whitewash gouache on the nearby trees; a takeoff of the 1960s  Pop Art Movement.
Poopcasso - PS artist.
Poptent - Dad standing over the chicks with wings spread keeping them safe from snow/rain/wind or predator.
Porch Peeps - The E's adoring EA's who sit on an evereggspanding porch overlooking the beloved cottonwood tree to pay homage to our eagles.
Post D-Epartum Depression - condition to what will happen to Eagleholics when eagles leave the nest.
Predicure - manicure for a predator.
Prey Buffet - whatever the parents happened to bring for dinner.
Prey Toy - meal tidbit used as plaything.
PSFS - Print Screen Finger Syndrome synonymous with copy, print and save web stream photo captures.
Puddle 'O Eaglet - description when too big for a cuddle puddle.
Puffmallows – the hatchlings first puffy and fuzzy phase.
R.O.T.N.S.O.L. - Rolling On Nest Squeeing Out Loud.
RWS - restless wing syndrome.
Raptor - a bird of prey, regal in the birddom. (Latin, one who seizes, from rapere).
Re-Decorahations - Eagles can redecorate, or nestorate, but only in Decorah can you Re-Decorate for the next nest season!
Raptortherapy - what all Eagleholics need after each season is over.
Reverse Sexual Dimorphism – In most cases when size differences exist between the male and female of a species, it is the male that is the larger of the two sexes. But in a few species, such as birds of prey and owls, it is the female is the larger of the sexes, and such a size difference is referred to as reverse sexual dimorphism.
Rictus - wide open mouth.
Riding The Rails – First perching times on the crib rails.
Rockem’ Sockem Baby Bots – Hatchlings pecking order squabbles with siblings.
Rug O’ War – A food item tugged between two eaglets trying to claim said item as their own.
Rumpicitis – Eagleholic affliction from sitting for 13+ weeks.
SED's - abbreviation for Sweet Eagle Dreams or Sweet Eaglet Dreams.
Screeching - sound associated with food frenzy.
Screech-fest - sound associated with food fest.
Screagling - screeches made by the eee’sScreeeeeeee - typed sound the eee’s make in one or multiple vocalizations; can interchangeable  with squeeeeee.
Scree-Geee’s – D12, D13, D14’s scree band.
Screeenami Siren – the screee alarm alert by juvies at an impending food drop.
Screeescendo – ear piercing frenzy of little eee vocalizations.
Separation Eagxiety - the anxiety that the last eaglet feels when it is left in the nest alone, sans siblings.
Shaking Juvie Syndrome - trying to get the gnats off ones head by shaking it.
Shell Helmet  - D20 emerged rolling out of its shell in 2014 and wearing a shell hat.
Snack Pack - another name for the eaglets crop, courtesy of "TeamCarnes 2nd grade class" in the 2015 season.
Snite - an eagle or eaglet sneeze.
Snuggle Huggles – simultaneous spooning and hugging while planted in a pile resting.
SOAR - Saving Our Avian Raptors - premiere rehab faciity in Iowa and present temporary lodging for injured eaglet D20 aka SOAR Baby.
Speggulation - wondering when those eggs will ever pip and hatch.
Spicules – knobby part of talons to hold onto slippery fish like suction cups.
Splish Splash -  three eaglets taking a bath in rainstorm 6-18-14
Sprawled Eagle - eaglet sleeping with wings spread covering a larger mass area than spread eagle.
Spread Eagle - eaglet sleeping with wings spread (see also sprawled eagle).
Squabbit - what we call the newest furry snack when we can’t  figure out if it is a squirrel or rabbit.Squeeep – babies vocalizations characterized as between a squeee and a peep.
Squeeeisnart – Mom & Dad’s fast and furious filleting of food at chow time.
Squeeesame Street - mythical play place for eaglets.
Squerky – unidentified leftover meal of either squirrel or rabbit jerky.
Squibetti - long entrail strands from mystery food source.
Squibbit – aka Squabbit – unidentified meal of squirrel or jerky.
Squirrel Slippers – fur bits taloned by the juveniles and worn around the nest.
Squish – unidentified meal of squirrel or fish.
StarBeaks – Eagleholics favorite corporate cawfee. Most popular blends: Decorah Decaf and Mocha Mantle.
Sub-Adult - juvenile eagle.
Sun Pose – aka Sunning – the regal eagle iconic horizontal wing drop stance associated with thermoregulation and E1, D12, D13, and D14 all D18, D19 and D20 offered their own versions.
Sun Pose Sundial - all 3 eaglets simultaneously in sun pose noted 5-20-14 by D18, D19 & D20.
SED – Sweet Eagle Dreams.
Sweagle Dreams - sweet eagle dreams.
Synchronized Switching - Mom & Dad's precisely timed incubation take-overs.
Syrinx - flap between esophagus and lungs for eagles vocalization sounds.
T.H.E. – abbreviation for ‘The Eagle Way’.
T.K.O. - Technical Knock Out -- usually preceded by eaglet beak bonking.
Tail Wiggle-Waggle -  movement of the eaglets tail after they realized they had one.
Tarsus - the section of vertebrate foot between the leg and metarsus.
Teeter Totter – using a stick on the side of the nest as a see saw.
The Beakerson’s – affectionate term of endearment given to Mom & Dad during their occassional tiff's.
Three Amigos – 2011 clutch of E1, E2 (D1) and E3. (see Tree Amigos for 2012).
Tippytalon - eaglets doing the ballerina thing.
Tree Amigos – 2012 clutch of D12, D13, D14.
Treeples – Eagleholics, aka Tree People.
Trunk Tower – the Cottonwood camera trunk that D14 ascended as its main lookout point.
Trunked – a vertical jump up to the tree trunk that D14 was most famous for doing.  D18 & D20 also utilized the cam tree trunk for vertical branching in 2014.  All three of these eaglets while "trunked" at the top of the cam, stayed long enough to give us some "selfie" photos.
Tweagles -  juvenile teen eagles.
Tweed Overcoats - when woolly down replaces white natal down.
Tween Preen - eaglets in their eee-awkard phase trying to get their feathers unfurled.
Twigging – going out on a twig prior to official branching.
Twiggs - playing with branches like Lincoln logs.
Twittering - calls made by young eaglets.
U-Branch – the U-shaped branch at the uppermost right of our screen frequented by Mom & Dad.
U.F.E. – unidentified flying eagle in background.
U.F.O - unidentified food object.
U.L.O. - unidentified laying object as when a well-intentioned but misguided fan dropped off a hay bale for extra nest warmth and seen in 2014 yonder field.
Whackdown - Wingwhack Wrestling takedown
Whatta - The best way to start a sentence!
Wilson - name given to the beloved cornhusk that resembled the volleyball in the film Castaway.
Windteruption - high wind day that causes the e's to lay low.
Wingercizing - excercizing the wings.
Wingertainment – new clutch fun in experiencing the joy of those little appendages.  The EA’s of course can be Wingertained by this action.
Wingpits - self explanatory.
Wing Nuts – Eagleholics, Beak Geeks or Bird Nerds … aka devoted fans.
Wing Smackdown - exhuberent wingersizing between two or more eagles resulting in a takedown.
Wing Whack - one eaglet stretching his wing while laying down and hitting his/her nearby sibling with it.
Wonderstruck - The overwhelming feeling produced by the EEeee's.
Y-Branch - the most beloved horizontal branch in N1, the old nest.
Yellow Suede Shoes - D20’s distinctive clown feet appeared to be wearing famous footwear.
Yonder Nest – name given to the new nest constructed by Mom & Dad in Fall, 2012.  Now known as New Nest or N2.