Black Skimmer Breeding Ecology and Behavior

Abstract

cubate and share parental duties until fledging. The growth characteristics of the Black Skimmer appear to follow the logistic model developed by Ricklefs. Only after the midpoint of the fledging period (about 11 days) do male chicks begin to grow more rapidly than females. Male chicks fledged at an average of 295.2 g while females fledged at 264.4 g. Adults captured a fish approximately every 5 minutes. Most foraging was done at low tide in marsh habitats. No pulse of high-fishing activity at dawn and dusk was noted as has been reported in the literature. Birds foraged alone in most cases, except when the immatures begin fishing. Apparently learning occurs at this time. Each young was fed on the average of 0.43 fish/hour during the day; the low rate may largely explain the low fledging success in 1973-1974. The extent of nocturnal feeding requires investiga- tion. The diet consists of 100% fish, with silversides and killifishes predominating.