New Jersey Division of Fish, Game and Wildlife Back to State of NJ Homepage Back to Fish, Game and Wildlife Homepage Back to NJ DEP Homepage

The 1999 Osprey Project

In 1999 we were a little surprised to see productivity return to a normal level. Nesting pairs numbered 331 -- a new high, and reaching closer to historic levels of 450-500 pairs.

Endangered and Nongame Species Program biologists conducted the aerial survey of nesting this year, which, combined with a lot of ground work and reports by volunteers, documented 331 nesting pairs statewide (Table 1). The Atlantic coast is still the stronghold, with 84% of the nests. Fifty-four pairs nested on Delaware Bay and River, an area where ospreys continue to expand.

Productivity in 1999 averaged 1.38 young per active nest, derived from knowing the outcome of 77% of nests. This level of production represents a 64% increase over the last two years, and is more "normal" for NJ ospreys (Figure 1). The problem faced by Atlantic coast ospreys, which had 0.6 production in 1997 and 1998, seemed to fade as production averaged 1.26 on the coast. Delaware Bay ospreys, on the Maurice River and Salem County marshes, averaged 2.27 young per nest.

ENSP biologists launched an investigation in 1999 to find causes of the poor production. We conducted nest watches on a regular basis to measure nest attendance by the adults, food deliveries and feeding rates. We also measured nestling weight at weekly nest visits and documented egg and chick losses. We are still analyzing this data, and hope to compare this year's findings with 1988 data to find where things may still be below average.

Other good news: The contaminant study conducted last year showed decreased levels of most organochlorine pesticides in both osprey eggs and their prey fish. The improvements correlate with improved nest success by Delaware Bay (Salem) ospreys. Also, in their "spare time," our assistants managed to recruit help and funds, and build and install 30 new nest platforms! Many thanks to all who contributed their time and money toward essential habitat.

We worked with the University of Minnesota's Raptor Center for a third year, outfitting five adult ospreys with satellite transmitters to track their migration routes. You can follow their migration on the Internet: (go to "Highway to the Tropics" then "Osprey Migration Data").

We are most grateful to our project volunteers for their continued work to record nest results, and/or for installing and repairing nest structures. Volunteers have made it possible for us to keep up with ospreys and potential problems.

Our thanks to Jersey Shore Audubon, who supported the aerial survey of nesting ospreys, along with Cape May County and Ocean County Mosquito Commissions. Thanks also to NJ DEP Division of Science and Research, who provided funding for researching nest failures. Special thanks to the Hyde and Watson Foundation and the Conserve Wildlife Foundation of NJ for donations of equipment. And many thanks to contributors and volunteers who donated nests!

Back to Fish, Game and Wildlife Homepage Back to NJ State Homepage Back to NJ DEP Homepage