The osprey, also known as fish eagle, is a large raptor that can be found near bodies of water where they prey on fish to eat. As a result of widespread use of DDT-based insecticides and lack of sufficient prey, the osprey birds in New Jersey were reduced to 53 pairs by 1973. A newly released report, however, revealed that the osprey's population is rebounding with about two birds being born per nest, which is twice the required number for the species to maintain a stable population.
Based on ground surveys that were conducted in June and July this year, the private and non-profit organization Conserve Wildlife Foundation of New Jersey and the New Jersey Division of Fish and Wildlife estimated that the population of New Jersey's osprey is now about 567 pairs.
A total of 686 chicks were born this year. Of the 420 active nests recorded, 339 produced an average of 2.02 fledglings per active nest, up from 1.92 last year and well above the minimum productivity rate of 0.80 young/active nest needed for a stable population.
"The comeback of these magnificent birds continues to inspire us, especially in combination with the parallel recoveries of bald eagles and peregrine falcons," said Conserve Wildlife Foundation executive director David Wheeler.
In 1974, the osprey was included in the New Jersey Endangered Species List when use of DDT-based pesticides affected the productivity of the birds. DDT thinned the eggshells of the birds causing the eggs to easily break because they cannot support the weight of the incubating bird. Reduced fish population also contributed to the decline in the osprey's population with the bird's productivity known to rely on the health of coastal fisheries.
It is for the osprey's diet consist mainly of fish that has made the bird an important indicator of the health of the environment. Biologist Kathleen Clark, from the Division of Fish and Wildlife who was part of the osprey survey project, said that the rebounding number of the species suggest there is an abundance of fish and a healthy aquatic system.
Conservation efforts as well as the ban on the use of DDT were also attributed to the boom in the birds' numbers. Clark said that the population of the birds will likely keep growing and that the birds will likely be upgraded from their "threatened" status.
"The results from this year were really positive for ospreys," Clark said. "You can never complain when you're about twice the minimum productivity needed, so we can expect the population to keep growing."