The animals are also tested for bacteria. Researchers are trying to establish the normal level of bacteria the birds and turtles host in their bodies. When the animals are exposed to stresses from the environment, the bacteria levels can go up, killing the animal. Park records show a steadily declining osprey nesting population from about 200 nests in the 1970's to less than 70 nests today. Blood tests indicate that the decline is probably due to cloudy water conditions and a decline in fish populations.
Ospreys are specialists.
They eat fish and they have to see them to catch them. The bald eagle population has been stable, about 50 nests per year. Eagles are generalists. They will eat almost anything including terrapin, osprey chicks and fish.