Large regal raptor
Head largely white
Black mask through eyes
Molted dark brown necklace
Body patterned brown and white
Hovers over water
Beating wings in flight.
Black patches in crooks of wings
Brownish black back
Wingspan up to six feet
Long sharp claws attack.
Plunges feet first for fish
Perch or shad to snag
Adjusts head first in talons
To reduce wind drag.
Makes sharp annoyed whistles
Yewk yewk or cheep cheep
Or when nest is threatened
Frenzied cheereek cheereek!
by Christopher Rudolph
Tucked away in the far corner of Wyoming, about 50 miles northwest of Cody, and just over Dead Indian Pass, you’ll find the Sunlight Basin and the 7-D Ranch, a western paradise. This small dude ranch is owned and operated by the Dominick family since the 1950’s and was the site of our two most memorable family vacations in 1993 and 2000. http://www.7dranch.com
A little chaffed and saddle sore by mid-week, I jumped at the chance to go birding on foot with David Dominick, and add some western birds to my life list. Hiking along a small stream bed in the shadow of the majestic Absorka Mountains and between sightings of soaring Golden Eagles, Clark’s Nutcrackers, Mountain Bluebirds, and Sagebrush Sparrows, I learned that David was not only an exceptional birder and President of the Denver Audubon Society in 1984-6, but also a key player in the saving of the Osprey and other large raptors.
DDT was first used as a pesticide to protect troops and civilians from the insect carriers of malaria and typhus during the second half of WWII. It was found to be highly effective and was eventually used extensively in agriculture after the war. By 1962 and the publication of Rachel Carson’s Silent Spring the effects on the populations of birds, and especially large raptors was becoming obvious.
By the process of “bioconcentration” the persistent breakdown products of DDT move up the food chain, accumulating in fatty tissues in increasing concentrations, eventually contaminating fish, the sole food source of the Osprey. DDT does not kill the raptors outright but insidiously alters the bird’s calcium metabolism in a way that results in thin eggshells, unable to withstand the weight of the incubating parent.
David Dominick received his B.A. in anthropology from Yale in 1960 and law degree from the University of Colorado in 1966. In 1971 President Nixon appointed him to the newly formed EPA as Assistant Administrator of Hazardous Materials Control, and he was instrumental in the Congressional passage of laws banning DDT and other predator poisons and pesticides in 1972. Without this intervention the Osprey was well on its way to extinction.
The Osprey (Latin derivation meaning “bone crusher”) is found on all continents except Antarctica. It is the sole member of the genus Pandion–there is no other bird like it. It is the only raptor that feeds almost exclusively on fish and therefore is always found in proximity to water, either salty or fresh. It has evolved specialized adaptations for this aquatic life. The feathers are heavy and oily to shed water, and also rank. Its been said you can easily identify a stray feather as being from an Osprey, just by its smell. The wings are over-sized for the weight of the bird to supply the added lift needed to haul the fish out of the water. The feet have raspy underpads and the outside talon can project backwards to effectively grasp the slippery fish.
In my yard on the Chesapeake Bay they are the largest, loudest, “king bird”, monopolizing the dock and waterfront from March to late September. They arrive from the south each March, almost exactly when the migrating Canda Geese head north, and leave in the fall just before the geese return for the winter. There are several active platform and channel marker nests nearby, giving constant Kodak moments of flyovers, hoverings, plunges, nestlings, etc. They cover my boats and docks with fishbones and guano, and break the weather vane of my sailboat, but so what–the spectacle is worth it.
The nest building activity is particularly fascinating. These birds mate for life but do not hang out together in their southern wintering grounds. But each spring the male and female meet again, back at the same nest, make repairs, mate, and raise another family. The larger female bird with the darker necklace is clearly in charge. I’ve witnessed a male bringing in the “perfect” large stick for the nest, only to have the female reject it and kick it overboard when the male was not looking. The second year birds spend their summer practicing nest building piling loose sticks and debris on every available surface, including the deck of my neighbor’s boat, but won’t mate and raise their own family until the following summer.
The Osprey usually lay 3 eggs, however the hatching is asynchronous setting up a chick rivalry with the older and larger chick usually winning the fight for food. The youngest chick is often pushed out of the nest and does not survive. The parents do nothing to intervene in this survival of the fittest. The chicks fledge in July, practice flying, diving, and fishing, and then follow the parents south in the fall.
If you’ve ever driven the Atlantic coast of Florida in the winter you’ll notice the abundance of “snow bird” license plates from New York, New Jersey, and New England. When you drive the opposite Gulf coast of Florida the licenses are from Michigan, Minnesota, and Ohio. Tagging studies of migrating Osprey surprisingly shows this same distribution with Atlantic coast birds ending up in Eastern Florida with some continuing to the West Indies and the northern part of South America. The Mid West birds like the Gulf coast, with the more adventurous going to Colombia and Brazil.
This is a success story for the Osprey with their numbers growing yearly. Each summer as I watch the hovering Fish Hawk see its prey from 50 feet, plunge head first toward the river, bring its legs and talons forward just before impact, and resurface with a flopping perch, I remember our summers in Wyoming, birding with David Dominick, and his part in ensuring the successful propagation of this unique bird.