Spatial Patterns of Breeding Parameters in Tropical Roseate Terns Differ from Temperate Seabirds

Abstract

Abstract This paper addresses the hypothesis that parental quality, expressed in terms of nest location, determines differences in breeding parameters between colonies and colony areas. I compared hatching date, egg size, egg shape, clutch size, breeding success and chick growth of Roseate Terns (Sterna dougallii) on the tropical Aride Island, Seychelles between: a) central pairs of an old colony, b) peripheral pairs of the same colony, c) pairs of old small sub-colonies and c) pairs of a recently formed colony. The breeding parameters at the small, old colonies were similar to those of the large, old colony and significantly different from those of the new colony, suggesting that parental quality is more closely related to sub-colony age than to sub-colony size. In 1998, a good breeding season, egg size was similar between all study areas, but clutch size in the new colony was significantly larger than that in the center of the old colony and the small sub-colonies. However, breeding success was signific...