Osprey chick |
Citizens United to Protect the Maurice River and Its Tributaries, Inc.'s Osprey Colony Project is one of our most successful endeavors. The project was established to help reestablish an osprey colony on the Maurice River and its tributaries.
The osprey, often referred to as the fish hawk, is a bird of prey: a raptor. Today the largest concentrations of osprey are found on the northeast coast of the U.S. But in the 1960's their populations plummeted; this marked the beginning of a national environmental crisis. By the 70's osprey were considered an endangered species; it was thought they might perish altogether, emptying the skies of osprey making their annual migrations to and from South America.
Biologists attach satellite transmitter to osprey |
Research showed that their decline was the result of chemical contamination by DDT (dichlor-diphenyl-trichloroethane). In concentrations up to a million times greater than those found in water, it was affecting the female bird's hormonal balance and in turn reproduction. Toxic effects inside the oviduct where the eggshell is formed caused insufficient calcium, resulting in thin eggshells. The incubation of the eggs could not be successfully completed because the weight of the parent's body would break the eggs. As a result, in the early 1970's there were only about one hundred pairs of osprey left of the thousand that had once nested between New York and Boston. Historically New Jersey had about 500 nests. By 1975 only 50 remained.
 Why care? Osprey, like many creatures at the top of a food chain, serve as biological indicators of contaminants in the environment long before the problem is evident in human health records. The osprey's plight has long served as one of the sentinels of a need for change. The osprey's food chain is an excellent model of our own vulnerabilities to toxins in the environment.
Older students might study the lengthy battle that ensued from Rachel Carson's best seller Silent Spring in 1962 (which warned of the DDT threat) and led to the ultimate banning of DDT by the EPA, in 1973. The ban has long stood as a precedent for current environmental law.
Intervention by humans has been the hallmark of osprey recovery. Along with a ban on DDT, one of the key ingredients to recovery has been the construction of nesting platforms. New Jersey now has approximately 310 nests. Osprey have gone from an endangered status to a threatened status and naturalists are hopeful of their full recovery.
Erecting nesting platform
photo: Judy Martin
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However, osprey are not out of danger yet. On the Delaware Bay shore NJ Endangered and Nongame Species Program biologists have documented a failing colony due to DDE, a derivative of DDT. And on the Atlantic Coast during the summers of 1997 and 1998 there were severe nest failures, possibly linked to food supply. Nevertheless, the Maurice River osprey colony has been on a steady increase, and we hope this pattern continues. We believe this increase is indicative of the improved water quality and abundance of prey species in the Maurice River watershed. In 1998 we banded 39 chicks, 2002 yielded an astounding 60 chicks. Forty one percent of the total chicks banded in NJ were from the Maurice River colony. (see osprey graph or download pdf)
In 1986 Citizens United's first pilot nest was erected on the Maurice River. Prior to that time one or two nests were erected by New Jersey Fish, Game and Wildlife and about 3-6 chicks fledged annually. Over the past 17 years Citizens United has erected over 30 nests. In addition to these nests we have constructed 6 for the NJ Bureau of Emergency Response for the top of oilspill boom pilings, 8 for NJ Division of Fish, Game and Wildlife, and 25 for Public Service Electric and Gas Co.'s Estuary Enhancement program. Our nesting platform is now NJ's official design. It is hoped that its distinctive "Y" shape looks more like a crook in a tree than a telephone pole to the osprey which use it. Since birds imprint to the structures in which they are raised, this shape may entice young pairs to use trees. However, osprey are known for the wide array of places in which they construct nests.
Cutting and drilling osprey predator guard.
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Citizens United is providing plans for our osprey platforms because we are frankly proud of our project and the design. Erecting osprey platforms is a formidable task and unsuitable for the majority of students. This project should be coordinated by experienced and knowledgeable persons. Maintaining nesting structures and banding birds involves special permits as well as real dedication. However, each year young students help assemble the nests. We have had boy scouts assist us in the construction and erection of platforms in order to earn their eagle scout badge. Older shop classes have offered to construct platforms that Citizens United then erects. We are most grateful to all the numerous volunteers that have participated in this project over the years.
During the summers of 1997 and 1998 volunteers helped to capture an osprey with the NJ Division of Fish, Game and Wildlife - Endangered and Nongame Species Program. (For information on the state osprey recovery program, check out this link http://www.state.nj.us/dep/fgw/osprey.htm.) Students can go to the internet and see the paths osprey take on migration by viewing research by Rob Bieregaard, University of North Carolina - Charlotte by using this link. The University of Minnesota no long tracks osprey migration. UNC estimates that 80-90% of first year birds perish during their first migration cycle.
Winter 2000 work party
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We often suggest the less cumbersome construction and erection of bluebird houses as a beneficial project for younger students. School yards are often suitable habitat for bluebirds, with open fields and old woodlots. Their numbers are jeopardized by peoples' naiveté to the numerous benefits of dead trees for nesting birds.
Why not think up your own habitat project? It can be rewarding, fun and lead to a lifelong appreciation of nature. These projects teach numerous skills: research, wildlife identification and classification, following directions, manual dexterity, construction techniques, wildlife habitat needs, measuring, composition of materials, cooperative work habits and all around good stewardship.
Osprey Nesting Platform Plans
Osprey Slide Show
Fish and Chicks
Eggs to Flight
Osprey platform parts list and diagram - 149 KB (.pdf)
Pictorial Instructions for Erecting an Osprey Platform(.pdf) Diagram and template for predator guard - 82 KB (.pdf)
Directions for predator guard (.doc - 11.7 MB) .sit .zip
CAD diagram of osprey platform (.exe - 2 MB) .zip
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