Priorities for Future Research

Forster’s Tern—its biology and ecology—has been less studied than other species of North American terns; only breeding ecology, foraging, and vocalizations have received significant attention. Loss of habitat due to degradation, draining, and filling or flooding of wetland habitats suggest that further studies of Forster’s Tern ecology are desirable. Wintering ecology of this species remains virtually unstudied, its movements are not well documented, and little is known about its ecology, behavior, and life history between fledging and first breeding. Behavior and care of prefledging young also remains little documented. More comparative studies among freshwater, brackish, and marine areas are desirable, as are comparative breeding studies between “marsh-nesting” (primarily on floating structures) and ground-nesting (e.g., cobblestone islands, dikes) colonies. Because low reproductive success within a given year is common, long-term studies of individually marked birds are required to determine longer-term population dynamics. Population trends cannot be measured easily in a species of such mixed breeding site-tenacity until more birds are marked individually and followed for several years. Vocalizations need to be studied away from breeding colonies and individual variation in vocalizations has yet to be explored. The use of vocalizations in individual recognition and the evolutionary divergence of vocal repertoires among terns also deserve attention.

As a “top of the food chain,” species, Forster’s Tern can serve as a biomonitor of potentially harmful synthetic chemicals, serving as a “littoral zone indicator” (Harris et al. 1985). Thus, continuing studies that have examined chemical contamin-ants in Forster’s Tern eggs and their effects on reproductive success would be useful, especially if extended to broader portions of the range of this species.