We have a new residence in LaGrange County, a large nest of sticks high up on a grain elevator. The nest belongs to an osprey. Ospreys are large birds, often mistaken for eagles because they have a white head, and in fact “fish eagle” or “fish hawk” are other names for this raptor because its diet is 99% fish. Osprey are smaller than an eagle. Their body measures 21-22 inches in length, with a wingspan of 60-71 inches. They are brown above and white below, with a broad brown stripe through the eye, which eagles don’t have.
Another unique feature of the osprey is that it has a reversible outer toe. This helps them to grab and hold on to fish. They also have barbed pads on their feet to keep the fish from sliding out of their grasp. The fish they catch must be near the surface, because an osprey can only dive 2-3 feet under water, so they like shallow water for their fishing. Most of their catch is between six and 13 inches long and weighs under a pound. They carry their catch back up to a perch or to their nest in their talons, carefully pointing the fish head-first for aerodynamic transporting. Pretty clever fellows!
Looking at the maps on the Cornell and Audubon websites, you would think ospreys shouldn’t be nesting here. They are birds of the north country or coastal areas in the summer and migrate to Central and South America in the winter in our hemisphere, but they are present on all continents except Antarctica. Ospreys were in trouble back when we sprayed everything with DDT, because the chemicals caused the egg shells to be thin and eggs were sometimes crushed by the weight of the incubating parent bird, but since that particular pesticide was banned they have made a remarkable comeback and are increasing in number and range. There are four known osprey nests in the Pigeon River Fish and Wildlife Area, plus the one I know of west of Howe.
Ospreys choose nesting sites that are open because they aren’t as maneuverable as other hawks. Humans often build nesting platforms in marsh areas and successfully attract the birds. Ospreys also build their nests on telephone poles, channel markers in rivers or along the coasts, and in dead trees, especially over water. Nests of new pairs are usually relatively small—less than two and a half feet across and only three to six inches deep, but after several years of adding sticks to the nest each season they may be more than twice that size. An osprey may lay up to three eggs, which hatch at intervals. When food is scarce, the older hatchling may dominate its smaller nest mate(s) and cause them to starve. I’ve thought a lot about our ospreys this past week with all the rain and especially the lightning, but when last I looked they were still persevering through it all.
Osprey start arriving in February and begin leaving in August, although since we are at the southern end of their breeding range they may hang around a little longer here. There is a resident population in Florida that doesn’t migrate at all. On the other hand, one osprey wearing a lightweight satellite transmitter flew 2,700 miles in 13 days from Martha’s Vineyard to French Guiana in South America!
Osprey aren’t backyard birds, but if you want to watch them, there are several websites with live osprey cams. The Cornell Lab has a link to one in Missoula, MT, at http://cams.allaboutbirds.org/channel/27/Hellgate_Ospreys/ and the Nature Conservancy has one in a nest in Alabama available from a link at http://blog.nature.org/science/. If you want to watch an osprey catch and carry a fish, numerous videos are available on YouTube. Just search for “osprey fishing.”