Avian Studies in Barnegat Bay
Barnegat Bay supports some of the largest and most diverse breeding colonies of birds in the state, as well as along the Atlantic coast. New Jersey is the center of the breeding population for Laughing Gulls, and contains healthy nesting populations of other gulls, terns, skimmers, herons, egrets and ibises. During the winter a wide range of ducks and brant pass through or overwinter. It is critical to maintain suitable habitats for nesting, migrating, and overwintering for this diversity of birds, and to reduce conflicts with humans wherever possible.
My avian studies in Barnegat Bay include population dynamics, behavior and ecology, and contaminants. My overall goal is to understand the factors that individuals and populations, with the hopes that these data can be used to manage and preserve stable populations of colonially-nesting birds in Barnegat Bay.
From 1976 to the present I (and other colleagues including Fred Lesser and Michael Gochfeld) have been conducting population studies of the birds that breed colonially in Barnegat Bay. This includes the herons, egrets and ibises, gulls and terns, and skimmers. I have concentrated on Herring Gulls, Laughing Gulls, Common Terns, Black Skimmers and Least Terns, recording the number of breeding pairs on the different islands from the north end of the Bay to Tow Island. For some species I have been recording reproductive success, and noting the causes of reproductive failures each year. The most complete data set exists for Common Terns and Black Skimmers because there are many colonies in Barnegat Bay, and they are species of concern. To understand population dynamics it is necessary to census the breeding population on each salt marsh island several times a summer. These studies can be found in two books: The Black Skimmer, and The Common Terns (see books).
Studies with these species have included behavioral observations aimed at understanding how predators, inclement weather, food supply, and neighbors of the same species affect reproductive success. I have also examined the effect of human disturbance and habitat loss on reproductive success. Since the birds are never exposed to only one threat, multiple threats interact to further reduce reproductive success. In most cases these studies involve long hours in observation blinds to reduce my impact, and in some cases, I have lived in a tent or old hunting shack from early April through August, on salt marsh islands to allow daily observations.
In recent years I have also been examining the levels of heavy metals in the feathers and eggs of colonial nesting birds in Barnegat Bay, and elsewhere in the New York bight. Since birds dump heavy metals in their feathers during their formation, feathers provide a record of exposure. By using young birds I can be assured that level of heavy metals represent those obtained from fish from Barnegat Bay.
Over the years funding for this project has come from the U. S. Fish and Wildlife Service, EPA, NJDEP (Endangered and NonGame Species Program), CRESP, and the Penn Foundation (through Trust for Public Lands).
