SURVEYS OF SELECTED AND TRADITIONAL BLACK TERN (CHLIDONIAS-NIGER) COLONIES IN BRITISH-COLUMBIA IN 1996

The Black Tern (Chlidonias niger) is a widespread, but local breeder, in much of the southern, central, and northeastern interior of British Columbia (Campbell et at 1990). On the coast it breeds at only 1 loca lity. The heart of its breeding distribution is in the Central Interio r, southern Sub-Boreal Interior and southern Boreal Plains ecoprovince s, but the largest concentration occurs in the Creston Valley in the S outhern Interior Mountains eco-province (Campbell et al. 1990). During 1996, 32 active colonies were surveyed with totals of 975 flying bird s counted, 133 nests found, and 501 breeding pairs estimated. Colony s izes ranged from 1 to an estimated 60 pairs. High water levels provinc e-wide resulted in additional breeding habitat being available, especi ally in meadows that are dry during most years. Over the past 2 decade s, the breeding distribution of Black Terns has apparently expanded no rthward and westward in British Columbia. Breeding terns are colonizin g new, managed wetlands which have relatively stable water levels duri ng the breeding season. Innumerable wetlands suitable for breeding occ ur over vast areas of the interior. Populations may be increasing in s ize in some regions, but have declined in the central-south interior. Some populations elsewhere, in areas with high rates of residential de velopment, have also declined, and a few colonies may have disappeared permanently. Although declines are better documented than increases, we do not consider Black Terns in British Columbia appears quite encou raging.