Breeding biology and the nature and importance of helper contributions in the cooperative breeding brown-headed nuthatch in a Texas urban population

This study examines the nature and importance of helper contributions in the breeding biology of an urban Texas population of Brown-headed Nuthatch (Sitta pusilla). The nature of cooperation and facultative adjustments in breeding male and female nesting behavior were also assessed by comparison of cooperative and noncooperative breeding attempts.;These data reinforces the benefit of helpers at the nest of cooperative breeders. Helpers provide compensatory help (especially in the nestling stage) to breeders (especially breeding females) and may benefit from indirect fitness and improvement of parental skills. Cooperative breeders may have a higher annual reproductive yield. Additionally, helpers may lighten workloads allowing cooperative breeders to store energy, reduce stress, and attempt two clutches per season.