Plasticity in nest site selection of Black Redstart (Phoenicurus ochruros): a response to human disturbance

Natural selection should favor flexibility in nest site selection when environmental variability influences individual fitness. Birds can modify their reproductive behaviors in response to predation cues. Similar to predation risk, human disturbance may cause birds to exhibit parental antipredator behavior. Effects of human disturbance on nest site selection of Black Redstarts (Phoenicurus ochruros) were investigated from 2006 to 2009. Black redstarts altered their manner of concealing nests following human disturbance. The Black Redstarts were found to shift their nests to deeper locations in the cavities in the subsequent breeding season after human disturbance. In an undisturbed study plot, nests were not well hidden in the first year but shifted to deeper positions in the nest cavities following disturbance from researchers. The depth in the nest cavity at which banded individual Black Redstarts nested was deeper than its previous nest location depth after human disturbance. The results obtained in this study suggest that the Black Redstarts cognize human disturbance as a predation risk and exhibit adaptive behavioral plasticity in nest site selection associated with concealment.