Abstract
Colony-site tenacity and reproductive success were examined in 19 colonies of black skimmers (R. niger) for 5 yr in New Jersey [USA]. Frequent colony-site shifts occurred and only 2 sites were occupied in all 5 yr. Although in 1 yr fledging success was nearly 0 due to flood ties, in most years tides destroyed < 25% of the colonies; predators destroyed up to 50% of the colonies. Skimmers usually abandoned unsuccessful sites and continued to nest in successful sites. Colony abandonment was greater in colonies subjected to predation pressures than in those subjected to flooding. This difference probably relates to the high predictability of future low reproductive success when a colony is destroyed by predators (high probability of future loss) as compared to floods (low predictability).