Parental provisioning in a variable environment: Evaluation of three foraging currencies and a state variable model

摘要: We estimated the reproductive success of black terns (Chlidonias niger) based on three optimal foraging currencies (maximizing net rate energy intake, daily delivery rate, and efficiency, respectively) a state variable model. There was broad range capture intervals (the time required for parent to single prey) when flight speeds predicted by were so high that they resulted in provisioning costs which parents could not fully recover through self-feeding. Whenever efficiency currency produced higher estimates success, lost comparatively less weight than foraged as rate-maximizers. If did experience any loss, made equivalent fitness projections. However, both these provided lower returns at longer intervals. number from model least one equal. Provisioning behaviour under much more flexible therefore able reduce their self-feeding days food particularly scarce, thereby increasing total nest. This possible currencies. Our results suggest efficiency-maximizing is likely provide are comparison with rate-maximizing alternatives. Furthermore, only predictions speed similar measured tern young natural nests.