Benefits of helpers in a cooperative breeder with high extra-group paternity: an experiment

My thesis explores how non-breeding helpers influence the investment of breeding female superb fairy-wrens, a cooperatively breeding bird with high extra-group paternity. Detecting the effect of helpers on breeders is often difficult due to confounding breeder quality. I experimentally control for female quality using wing feather clipping and examine the impact on reproductive behaviour and survival. Clipped females decrease reproductive investment but increase survival, indicating flexible maternal investment. Helpers only compensate for the effect of feather clipping during offspring feeding. My experiment reveals context-dependent helper contributions that add to our understanding of how cooperative breeding behaviour is maintained.