In cooperatively breeding Southern Pied Babblers, non-breeding helpers reduce their incubation effort on hot days, but breeders do not. This significant decline in helper contribution to incubation at high temperatures could help to explain why previous research has shown that larger pied babbler groups do not have higher breeding success than smaller groups during hot weather.
Funding
DSI-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology
University of Cape Town
Oppenheimer Memorial Trust (grant number 20747/01)
British Ornithologists’ Union
Australian Research Council (grant number FT110100188)