Nutrient reserves and the energetics of reproduction in American coots.

Abstract

Fulica americana were studied at Delta Marsh in S. Manitoba. Feeding conditions before arrival can affect subsequent reproductive output. Fat reserves may function as a threshold that influences the initiation of breeding; protein reserves and time of arrival influence the timing of a nesting attempt. Territory quality is important and can result in the termination of laying before nutrient reserves are depleted. By distributing costs of clutch formation before (through nutrient storage) and after (through increased biparental care of eggs and young) clutch formation, the required energy intake concurrent with egg-laying is substantially reduced in female coots. -from Authors