Parental, social and environmental factors associated with hatching failure in Florida Scrub-Jays Aphelocoma coerulescens

Authors


Corresponding author.
E-mail: twilcoxen@millikin.edu

Abstract

Hatching failure within clutches of eggs occurs to varying degrees in many avian species. We investigated predictors of hatching failure in a population of Florida Scrub-Jays, for which hatching success has been monitored for 15 years. We assessed whether hatching failure was related to parental traits (e.g. age, experience as a pair or body condition), lay date, social structure (e.g. number of helpers), environmental conditions, or some combination of these. We used linear mixed models and Akaike’s information criterion to determine the models that best explain observed patterns of hatching failure. The best model showed that increased hatching failure was associated with below-average rainfall during the breeding season, and was more common for newly established breeding pairs than for pairs that had previously produced one or more clutches together. Other contributing models suggested that hatching failure was greatest for the youngest and oldest female breeders. Some aspects of our findings are consistent with conclusions drawn from other species. However, as a whole, our analyses suggest that hatching failure in the Florida Scrub-Jay is influenced by a complex set of environmental and parental factors.

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