Risk taking during parental care: a test of the harm-to-offspring hypothesis

Amount of risk taking during parental care is often explained in relation t o the reproductive value of the offspring. The "harm-to-offspring hypothesi s" focuses on the relative harm a period of no parental care can do to the offspring. According to this hypothesis, parents should take greater risks for offspring in poor condition than for offspring in good condition. We ma nipulated offspring condition in the pied flycatcher (Ficedula hypoleuca) a nd tested the harm-to-offspring hypothesis by exposing parents to a predato r model (a sparrowhawk, Accipiter nisus). Time elapsed until a parent first entered the nest-box was used as a risk-taking measure. Parents spent sign ificantly shorter time until first nest visit for offspring in poor conditi on than for offspring in good condition. Hence, the harm-to-offspring hypot hesis was supported.