Nature versus nurture: Structural equation modeling indicates that parental care does not mitigate consequences of poor environmental conditions in Eastern bluebirds (Sialia sialis)

1. How organisms respond to variation in environmental conditions and whether behavioral responses can mitigate negative consequences on growth, condition and other fitness measures are critical to our ability to conserve populations in changing environments. Offspring development is affected by environmental conditions and parental care behavior. When adverse environmental conditions are present, parents may alter behaviors to mitigate the impacts of poor environmental conditions on offspring.

2. We determined if parental behavior (provisioning rates, attentiveness, nest temperature) varied in relation to environmental conditions (e.g., food availability, ectoparasites) and if parental behavior mitigated negative consequences of the environment on their offspring in Eastern bluebirds (Sialia sialis).

3. We found that offspring on territories with lower food availability had higher hematocrit, and when bird blow flies (Protocalliphora spp.) were present growth rates were reduced. ...