How avian nest site selection responds to predation risk: Testing an 'adaptive peak hypothesis'

Abstract

1. Nest predation limits avian fitness, so birds should favour nest sites that minimize predation risk. Nevertheless, preferred nest microhabitat features are often uncorrelated with apparent variation in predation rates. 2. This lack of congruence between theory-based expectation and empirical data may arise when birds already occupy ‘adaptive peaks’. If birds nest exclusively in low-predation microhabitats, microhabitat and nest predation may no longer be correlated even though predation ultimately shaped microhabitat selection. 3. This ‘adaptive peak hypothesis’ was tested for a population of Yellow Warblers (Dendroica petechia) focusing on two nest microhabitat features: concealment and height. Experimental nests measured relative predation risk both within and outside the microhabitat range typically occupied by natural nests to examine whether nest site choices made by birds restricted our ability to detect microhabitat effects on predation. 4. Within the natural range (30–80% concealment, >75 cm height), microhabitat–predation relationships were weak and inconsistent, and similar for experimental and natural nests. Over an extended range, however, experimental predation rates were elevated in exposed sites (

Citation

Latif, Quresh S.; Heath, Sacha K.; Rotenberry, John T. 2012. How avian nest site selection responds to predation risk: Testing an 'adaptive peak hypothesis'. Journal of Animal Ecology. 81: 127-138.