Parents or Predators: Examining Intraseasonal Variation in Nest Survival for a Migratory Passerine

The condor

Robin Hirsch-Jacobson¹ 

关键词: Acadian Flycatcher;    Empidonax virescens;    nest survival;    nest-visitation rates;    reproductive strategies;    seasonality;   

DOI  :  10.1525/cond.2012.110057

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. For birds, risk of nest predation can vary within a breeding season, but few data exist that explain why such variation occurs. We investigated intraseasonal variation of nest survival of the Acadian Flycatcher (Empidonax virescens) in Midwestern forests and tested whether four of the adults' reproductive strategies (clutch size, nest concealment, nest visitation rates, nest height) explained trends in survival across the breeding season. We also used video cameras to identify predators at 40 nests, which allowed us to determine whether variation in predation rates by category of predator (e.g., birds, mammals, snakes) explained overall seasonal variation in predation rates. The flycatchers' nest survival had a quadratic relationship with Julian date but generally increased through the breeding season. Nest height increased as the breeding season progressed but did not explain any variation in nest survival. No other reproductive trait exhibited significant intraseasonal variation. Overall, pred...

【 授权许可】

CC BY