chapter  5
26 Pages

Population Trends of Colonial Waterbirds in Barnegat Bay

Population studies ideally include the size, structure (age distributions), and replacement of individuals over time. These measures aid in determining whether a given population is stable, increasing, or decreasing for the purposes of management and conservation. In the early 1900s, population data were developed for determining hunting quotas, particularly for ducks and waterfowl, and later for big game, and still later for conservation of endangered and threatened species. It is impossible to manage, conserve, or sustainably exploit populations without some idea of their numbers, or at least an index of population size and temporal trends. Except for endangered species, where all individuals may be counted, it is impossible to count every individual, so population estimates are based on sampling.