Eagle Cam Update

Week of March 20, 2017

It was a busy week, it was a typical week, it was the best of all possible weeks in our favorite eagle nest. The adults continued to hunt, bring food to the nest, and feed their babies. The little ones continued to eat, sleep, and grow. The eaglets also exhibited exploratory behavior that’s a sign of healthy development by stepping outside of the bole, or the cup-shaped depression where the eggs were laid.

All three eaglets are now roughly the same size, suggesting that all are getting fed and may successfully fledge the nest (fingers crossed!). Alternatively, the presence of a “runt” could indicate a physical impairment, such as a deformity or injury, or that the larger siblings are eating all the food. Perennial viewers of our video stream may recall such things happening in prior years.

This week, EagleCam viewers may have seen a lot carnage in the nest. Indeed, many meals were delivered, including fish and mammals, but this is typical and necessary for sustained eaglet growth. Some viewers sent us messages about an especially graphic scene in which a squirrel, still living, was brought to the nest. Different viewers inevitably will have different opinions about predator-prey relationships but, like it or not, this is an intrinsic part of nature. Carnivorous species, like eagles, derive their energy and nutrient requirements from animal tissue. So do many humans (although we prefer that our meat isn’t moving when we stick a fork into it). The scene with the squirrel is a reminder to watch the EagleCam with caution, especially when young children are present. Real nature can be fascinating, but it isn’t a Disney flick.

Food For Thought

For many, the best part of traveling to other states and regions is tasting the local cuisine. For example, the Carolinas specialize in barbeque and ribs, Louisiana uniquely offers Creole and Cajun dishes, and here in Minnesota we love a good Juicy Lucy, fish-fry Fridays and cheese curds. Similarly, bald eagles (and other widely distributed species) specialize on foods that are locally abundant and available where they live. Therefore eagles in different regions may have different diets.

Because Minnesota has lots of lakes and forests, Minnesotan eagles primarily eat fish and small to medium-sized mammals (including cats, so keep your fur babies inside!). Alaskan eagles prefer to scavenge salmon carcasses, and eagles living in the Prairie Pothole Region likely specialize on waterfowl. One commonality among eagles, especially juveniles that are not yet skilled hunters, is that they opportunistically eat carrion (decaying animal tissue). Roadkill may sound gross to you, but to an eagle it’s a meal.

Prey type is directly associated with method of prey capture, which includes hunting in flight, from perches, and on the ground, as well as wading in water, cooperative hunting, scavenging, and piracy. That last method, piracy, includes stealing prey from other birds or mammals and displacing others from scavenging sites.

After catching and killing prey, eagles go to work tearing off little pieces of tissue small enough to swallow. This is a mighty task without the use of hands and teeth! Once swallowed, the tissue first arrives in the crop, which basically is a storage organ that allows birds to consume more food than would otherwise fit in their stomach. From there, the tissue travels to the proventriculus, or upper stomach, where it is broken down by digestive juices. Next, it is further ground up, with the aid of grit, in the ventriculus (gizzard) or lower stomach. Fats, sugars, and proteins are broken down in the small intestine by bile and enzymes and absorbed into the blood stream. As with all birds, eagles urinate and defecate simultaneously through their cloaca, which also is used for copulation and egg laying.

Are you interested in birdwatching but need a little help getting started? Fear not, Minnesota Parks and Trials is hosting a Birdwatching for Beginners event this Saturday, March 25, at Brown’s Creek State Trail. Binoculars and field guides will be available. Meet on Hazel Street in northern Stillwater by 8:00 AM, and contact Linda Radimecky (651-231-6968, Linda.Radimecky@state.mn.us) for more information.

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