YELLOWSTONE'S WILD WORLD

While we were in Ennis, Montana a few days ago we found more ospreys nesting than any other place we have ever seen. All of them were nesting on artificial platforms, some of which are put up to keep ospreys from nesting on electrical power poles, and possibly electrocuting themselves, but there were lots of platforms in front yards and at fishing access sites. The western meadowlark is Montana’s state bird but Ennis should have a town bird, the osprey. I would love to live in a town that cares as much about ospreys as the people in Ennis.

Ospreys are related to hawks, falcons and eagles but they are in their own family. They are found on every continent on earth except Antarctica. The way they capture their prey is what makes them unique. Osprey eat almost entirely fish. There are other birds that eat fish but none that are as exquisitely adapted to fish catching as ospreys. They can catch fish that weigh as much as they do, and even more remarkable, they can take off from water they are totally submerged in, many times with a heavy fish in tow. It is hard enough to fly out of water, much less when you are carrying something that weighs as much as you do.

The scales on their talons face backwards to help them hold a slippery fish and they can close their nostrils when they dive. Osprey are sight fishers. They hover above a fish and then dive down feet first into the water. Their talons are different than most birds. They are zygodactylous. Imagine you only had four digits on your hands but two of them where opposable like your thumb. Ospreys can grab a fish with 2 talons on one side of each foot and two on the other. That also allows them to carry the fish with its head pointing into the wind. To be able to carry the maximum amount of weight they must carry fish in as streamlined a way as possible, and their toes allow them to do that.

Ospreys usually mate for life. When they are ready to nest in the spring they begin bringing sticks to a nesting platform or into the upper reaches of a tall tree. I don’t know if you pay much attention to how they construct their nests. Some are no more than a foot or so high and some are over five feet. There is lots of individual variation in height but in Wyoming, Idaho, and Montana there is one thing that rarely varies. They all have plastic orange baling twine in their nests. I don’t know if that is their way of decorating their home or what, but I know they always seem to find some and incorporate it into their nests. Once the eggs hatch the female stays at the nest to protect the chicks and incessantly scream at the male to bring in more fish. I have seen a female with her crop bulging calling to the male for more fish. I almost always feel sorry for male ospreys.

My husband and I used to take students on a 6 week summer field trip where he taught environmental science and I taught plant taxonomy. We always had great students. (I’m talking about you Wendy and Jay.) We traveled to several parks in New Mexico, Arizona, Utah and Wyoming, including Grand Teton and Yellowstone National Parks. One day we were walking along the Snake River near the Oxbow in the Tetons. My husband was talking about ospreys and how well adapted they are for catching fish. He had just mentioned how bald eagles sometimes try to steal fish from an osprey when, almost as if we had cued it, an osprey carrying a fish flew downstream right in front of us, with a bald eagle right behind it! We couldn’t believe our luck! Bald eagles are larger, more powerful birds than ospreys, but they don’t maneuver as well as ospreys, except when an osprey is carrying a fish. The students had just learned that and they spontaneously started running along the riverbank cheering the osprey on to its nest. I don’t really know if I was rooting for the osprey or the eagle, but I know I had a good laugh when they started running. I’ll bet you not one of those students has forgotten how ospreys carry fish.

And incase you were wondering that Snake River osprey did keep it’s fish.