Nest defence intensity in House Sparrows Passer domesticus in relation to parental quality and brood value
Abstract
We investigated, whether brood value (laying date, brood size, nestling age and condition) and parental quality (condition, male badge size) affect experimentally provoked nest defence in a population of House Sparrows in the Czech Republic. Females did not adjust their nest defence to the brood value and males did so only partially, tending to defend the early broods more intensly.
The birds did not adjust their nest defence to quality or defence intensity of their partners. Males defended their nests more intensly than females and increased the intensity of defence with their badge size.
As male contribution to nest defence may affect the breeding success, we hypothesize it could be used as a signal of potential parental investment by females.