The National Eagle Center is a proud educational partner of E4Kids. Located on the banks of the Mississippi River in Wabasha, MN the National Eagle Center is home to rescued bald and golden eagles. During a visit to the National Eagle Center, you can experience these magnificent creatures up close and learn about the ecology, biology and natural history of eagles.
During the nesting season, visitors to our classroom often see the live E4Kids web cam. Over the years of watching and working with Eagles4Kids, we have learned a lot about the day-to-day happening at this bald eagle nest. Our naturalists are excited for another season of learning along with the Eagles4Kids audience.
Throughout the nesting season, National Eagle Center naturalists will blog about what is happening at the nest. If you have other questions be sure to check out the
daily updates and frequently asked questions on the Eagles4kids website. The National Eagle Center also offers more information about eagles in the LEARN section on our website. (www.nationaleaglecenter.org/learn/faq)
All of the staff naturalist educators at the National Eagle Center will be contributing to the blog during the nesting season. Each of us has our own unique personality and style, and just like it our live eagle programs, you’re bound to learn something new! To learn more about each of the naturalists, please visit www.nationaleaglecenter.org/live-eagle-programs.
We look forward to sharing with you!
April 23, 2015
Peregrine falcon in flight - Photo by Carol Knabe
Bald eagles aren’t the only raptors nesting at this time of year in the Mississippi RIver Valley. Keep your eyes to the skies and look for the fast and fierce peregrine falcons.
Peregrine in Latin means wanderer and this bird has one of the widest ranges in the raptor world. They are found on every continent except Antarctica. The peregrine falcon is a medium sized falcon. It weighs one to two pounds and has a wingspan of just over three feet. It is considered the fastest animal on the planet! When in a dive (or stoop) the peregrine can exceed 200 miles per hour.
Like most falcons, the peregrine is a bird eating bird – often seen hunting pigeons and starlings urban areas. Peregrines will eat just about anything. An astonishing 450 bird species have been documented as prey items in North America. Worldwide the number is probably closer to 2,000 bird species. Prey as small as a hummingbird and as large as a sandhill crane have been taken by these amazing aerial predators.
Close up of a captive peregrine falcon. Photo by Scott Mehus
Peregrine falcons do not build a nest like most birds but rather have a “scrape” or slight depression in the rock or gravel. The male and female both fiercely defend the territory. The female will lay up an average of three to four eggs. The male and female take turns incubating after the final egg is laid. After one month, the young falcons hatch. They grow quickly and by the time the chicks are about 40 days old, they are taking their first flights.
Like the bald eagle, the peregrine falcon population declined due to the use of DDT (dichloro-diphenyl-trichloroethane). DDT affected the way the female processed calcium and caused the eggshell to be thin and deformed. The parents would often crush the eggs trying to incubate them.
By 1962, there were no known nesting peregrines east of the Rocky Mountains. Thanks to captive breeding efforts, peregrines were reintroduced to much of their historic range. In 1987, peregrines nested successfully for the first time since the 1960’s. Peregrines have also adapted well to human environments. In Minnesota and Wisconsin, peregrines can be seen nesting on cliff ledges, bridges and skyscrapers.
One of the National Eagle Center staff members volunteers her time for an organization called Midwest Peregrine Society. This organization works in 13 states and 2 Canadian provinces monitoring the population of peregrines. Each year volunteers locate and monitor nest sites. When the chicks are old enough each one gets a band placed around their leg, and a small blood sample is taken. This information is entered into a database giving researchers the ability to track individual birds and to help monitor long term changes in the environment. For more information on the project visit Midwest Peregrine Society’s website at http://midwestperegrine.umn.edu/.
Today in the Midwest the population has rebounded and there are more than 220 territories. The peregrine falcon was removed from the federal endangered species list in August, 1999. There are now approximately eight known peregrine nesting sites within 20 miles of the National Eagle Center. Another success story!
April 6, 2015
Hatch day is coming!
Hatch day is coming! Here at the National Eagle Center we use Earth Day, April 22nd, to advance the ages of all our eagle ambassadors. Several of our eagle ambassadors were hatched in Wisconsin sometime in April, so Earth Day seemed like a good day to celebrate their hatch days. Each year on Hatch Day, we celebrate the eagles with special programs and activities – see the schedule here (http://www.nationaleaglecenter.org/hatch-day/).
In southern Minnesota and Wisconsin, eggs are usually laid by the first week of March, though the exact timing can vary from pair to pair. The nest just across the river from the National Eagle Center in Wabasha, MN is typically a bit later than others in the area. They have just started incubating, so we expect their hatch day to be around the first week of May. Egg laying in the northern Minnesota and Wisconsin takes place mid to late March, as migratory eagles return to these northern breeding territories.
Bald eagles typically lay two to three eggs. An eagle egg is very similar in size to a goose egg. It weighs about 144 grams (5 oz) and is similar in shape to a chicken egg. Bald eagle eggs are off white to ivory color and occasionally have some faint blotches of brown. They incubate the eggs for 33-35 days, eagerly awaiting Hatch Day!
Blair and Taylor have been patiently incubating their eggs for more than 40 days. While it’s possible the eggs might still hatch, its getting less and less likely that we will see eaglets this year. The good news is that both Blair and Taylor seem to have figured out what it takes. Maybe they will have better luck next year!
Eagle eggs hatch in the order they were laid because as soon as the first egg is laid the eagles begin incubation of that egg. Then, a day to several days later the female eagle will lay the next egg. This means younger eagle siblings are often 2-3 days younger than the next oldest eaglet. This is very different from the American Robins that our now returning to our area. The female robin lays an egg then leaves the nest, comes back the next day and lays another egg. The female robin only begins incubation after she has laid all the eggs (typically 3-5) and as a result, baby robins in a nest all hatch at the same time.
Eaglets break through the shell by using their egg tooth, which is a pointed bump on the top of the beak, this process is called ‘pipping’. It can take from twelve to fifty hours after making the first break in the shell for the eaglet to hatch. During this process, you can often see that the parent eagle is aware that this is going on beneath her. She may be able to feel this process going on, but she can probably also hear some of the pipping. Once the eggs begin to hatch, the parent’s vigilance is nearly constant. When the pipping starts, food is brought to the nest as if in preparation for the forthcoming hatching.
Newly hatched, eaglets are soft looking and have grayish-white down that covers their small bodies. At this stage, they have small wobbly legs that are too weak to hold their weight. The eyes are partially closed with little vision, especially compared to what their eyesight will be like as an adult. The chicks are very vulnerable and will rely on round the clock care from their parents. Early on the female does most of the care at the nest while the male provides food for the rapidly growing family.
March 5, 2015
Last week, many of us watched with concern as Blair left the egg unattended in very cold weather for what seemed like a long time.
So what was happening?
When incubating eggs, eagle parents typically take turns incubating so that each parent can go find food while the other keeps the eggs nice and warm. Both parents have a ‘brood patch’, an area of bare skin that they place next to the egg to transfer their body heat and keep the egg warm. Most eagle pairs take turns incubating and hunting. The female often spends more time incubating, and the male brings food back to the nest for her.
Last week, despite lots of calling by Blair, the male didn’t return with food, or take his turn incubating. Eventually, Blair left the nest to find food for herself. But that left the eggs unattended in freezing temperatures.
Tough stuff huh? For some viewers it has been very hard to watch those eggs just lay there freezing.
At this point, we aren’t sure whether the eggs are still viable. If they froze, the eggs will not hatch. If it is clear they won’t hatch, Blair could mate again and lay a new clutch of eggs. But, we don’t know for sure whether the first two eggs are still viable or not.
When we watch a web cam and peer into the daily lives of wild eagles, we have to be ready to watch the good and bad. The students at Blair-Taylor have known that whatever happens, we will all learn something. It might be hard to watch, but we can always learn something about what life is like for wild eagles.
So why would Blair leave the eggs unattended in the cold? Why didn’t the male help with incubation?
Maybe it is just inexperience. Possibly one or both of the birds are first time parents. It could be that simple. Many first time eagle parents are not successful; they are just learning what it takes to raise a family.
Blair has urged him to help with the incubation, so she seems to know what is required. But, ‘Mister’ has not responded by incubating the eggs. Likely the eggs were fertilized by Taylor, the male Blair was seen mating with earlier in February. Taylor was not seen near the nest for a week or so, and in the meantime another male, Mister, has been hanging around. It could be that since Mister just showed up, he is still trying to bond and mate, rather than focusing on incubating and later nesting behaviors.
Another possibility is that we are witnessing 'sexually selected' or 'paternity-influenced infanticide'. A bird may sometimes destroy an egg or even kill a young in the nest if it is not the parent of that young. This often happens when the male believes he is not the one who fertilized the egg. In the E4K nest, the male may not have physically destroyed the egg, but by choosing to not help with the incubation duties, he destroyed the chances of the eggs’ survival.
Birds might also engage in infanticide if food resources are very scarce, and there is not enough to feed all the young. but, that doesn’t seem likely in this case.
Now that Taylor seems to be back, maybe we will see more involvement in incubating. Maybe its not too late for the eggs. We will have to wait and see. As always, we will continue to watch and learn from the happenings at this wild bald eagle nest.
March 23, 2015
Recently some folks were “grossed”out when they saw Blair cast a pellet.
Pellets are very important to the digestion of eagles and many other birds. Why?
Eagles and other raptors eat small animals and birds, often consuming the whole animal. After they eat an animal, they sometime cough up, or cast, a pellet.
What is a pellet? A pellet is a small package of all the undigested material from the animal the bird has recently eaten. Typically pellets contain fur, feathers, and sometimes bones.
You might be familiar with owl pellets. They eat small animals such as mice or voles, and afterwards cast up a pellet. Owl pellets are different from eagle pellets. Owl pellets contain fur and bones from the animals they eat.
Eagles have such strong stomach acid that they digest bone easily. For eagles, the bone is a good source of calcium that the eagles can use for their own bones and in forming the eggshells. But there are some things even an eagle can’t digest. They don’t digest fur or feathers. Actually, there isn’t any nutritional value to these items, so they don’t waste energy trying to digest them. They simply cast them up in a pellet.
Here are some examples of owl pellets and eagle pellets.
On the left of the pellet tray there are pellets from an eagle at the National Eagle Center in Wabasha, MN. Notice the lack of bones in these pellets, since eagles can dissolve the bone material.
On the right there are pellets that have come from Alice the Great Horned Owl from the International Owl Center in Houston, MN. Notice the bone material along with the fur of whatever she ate the day before. Since owls do not have the strong stomach acids to digest the bones, their pellets contain all the bones of the animals they consume. Many school kids get the chance to dissect these in science or biology class in school to actually put the pieces together and figure out what that owl ate the day before.
How do these pellets get formed? Birds, including eagles, have a part of their stomach called a gizzard. The gizzard is an area where food is ground down to a fine consistency for fast digestion. In eagles this is where pellets are formed. Here the muscles of the gizzard churn, packing the fur or feathers together with digestive juices into a compact shape.
Once the pellet has been formed it is pushed up from the gizzard where it will be cast or coughed up from the bird’s mouth. Casting of the pellet helps clean out the digestive tract and any parasites that could potentially make that bird sick.
When working with eagles in a captive setting we are always happy to see a pellet being cast. This lets us know that the birds are digesting their food properly and maintaining a good diet. At the National Eagle Center, we look for pellets to know when the bird will be hungry. If they have had food with fur or feathers recently, the pellet lets us know they have digested that food and should be eager to eat their next meal!
Video of Harriet casting a pellet from 3-22-15
June 17, 2015
Learning about other creatures that live where eagles live!
Picture by Carol Knabe
Have you ever been chased by a blackbird or scolded loudly as you rode your bike a little too close to an unseen nest? You’re not alone, these bold little birds will even chase off an eagle that flies too close! Let’s learn a little more about these mighty defensive birds.
Red-winged blackbirds are one of North America’s most abundant birds. They are a familiar sight in marshes, by rivers and lakes, along fields and grassy roadsides. You might have seen them perched on a cattail and hear their distinctive conk-la-ree, the song of spring. They can be found across North America, from south-east Alaska and Canada to the Gulf Coast, and even in Central America and the northern Caribbean islands.
The male red-winged blackbird is a magnificent sight to behold! He is a glossy black color with bold red and yellow shoulder patches. Females are smaller and have a coloring that keeps them camouflaged. She is a rather drab brown with streaking patterns on her underside and a yellow wash on her throat and sports a very prominent white eyebrow stripe that give her a lot of personality! Both males and females have slim, cone shaped beaks, which are used for capturing insects and harvesting seeds.
In early spring, male red-wing blackbirds spend most of their day perched high above their territory fending off invading males and doing whatever they can to be acknowledged by females; puffing out their feathers, fanning their tails and holding their wings so that their red shoulder patches are prominent. Females choose a male and his territory, but she won’t be the only female there. Male red-winged blackbirds mate with multiple females, and five or more nests might be found in a single territory. With all this going on in their territory, it’s no wonder red-wing blackbirds are so defensive!
Females prepare an open cup nest by winding plant materials around vertical stems. The nest is normally built in vegetation near the ground or even in vegetation just above the water’s surface. Mud, wet leaves and wood are often collected to line their nest for added strength. To provide a soft surface for the eggs, females finish the nest by lining it with dry grasses.
Red-winged blackbirds typically lay three or four blue-green eggs. Females incubate the eggs for only 10-12 days before the young will hatch! It’s also the females that do the majority of the feeding, while males are on constant alert, watching for danger and defending the territory.
Just 11-14 days from hatching the chicks leave their nest behind. It’s hard to believe but in just a few weeks the young bird will be completely independent from its parents. Juveniles must learn quickly to survive. Not only must they learn to be efficient at flying but also learn where to find food and how to avoid predators like hawks, snakes or foxes. Red-winged blackbirds reach adulthood after two-three years and become dedicated parents like the generation before them.
Red-winged blackbirds often gather in large flocks. At times, congregations can reach several million birds. Red-winged blackbirds feed on insects and by eating seeds, they help keep weed populations in check. However, a huge flock of red-winged blackbirds can damage farm fields, feeding on grain and seed crops. Control measures are sometimes used to reduce crop damage, including use of traps, poisons, and surfactants, all of which can harm birds.
Today red-winged blackbirds populations are still considered healthy, with an estimated global breeding population of 130 million. But, the red-winged blackbird population has declined 30 percent since 1966.
History has shown us that just because a bird is numerous, doesn’t mean it can’t be driven to extinction. In the 19th century, the passenger pigeon (Ectopistes migratorius), was the most abundant bird in North America.
"One night when they went to bed the sky was clear and the woods were still. But when they awoke in the crisp autumn morning the air was full of the noise of wings, and flocks of birds flew like clouds across the sun. The passenger pigeons were on their way south. They filled the trees in the woods. They came down in the fields and gardens, feeding on whatever seeds and grains they could find. The last birds kept flying over those which were feeding in front, in order to come at new ground, so that the flock seemed to roll along like a great moving cloud.
Tom and Warren armed themselves with sticks and went out with the hired men. But for once Caddie stayed indoors. She liked hunting as well as the boys. But this was too easy. This was not hunting -- it was a kind of wholesale slaughter. She knew that the Indians and the white men, too, caught the birds in nets and sent them by thousands to the markets. She knew that wherever the beautiful gray birds went, they were harassed and driven away or killed. Something of sadness filled her young heart, as if she knew that they were a doomed race. The pigeons, like the Indians, were fighting a losing battle with the white man.”
...from Carol Ryrie Brink’s Newbery award-winning children’s book based on a Wisconsin pioneer, “Caddie Woodlawn”
Despite these huge numbers, the last passenger pigeon died in captivity at the Cincinnati Zoo in 1914. Today, all we have left of the passenger pigeon is its story.
The story of the passenger pigeon reminds us that just because something is abundant today doesn’t mean they can’t be gone forever. We need to treat all creatures with respect, and understand their place in the environment to ensure that they’ll be around for generations to come.
Author: Anna Christenson