Foraging constrained by heat and dark

Yitzchak Ben Mocha of the University of Konstanz, Germany, and colleagues from Israel investigated the daily activity of a wild desert bird, the Arabian babbler (Argya squamiceps). They show that the birds initiated their daily activity within a 45-min window around morning twilight and became active earlier in response to recently experienced heat. The birds were not active in complete darkness, probably owing to increased predation risk and low foraging efficiency. Summer temperature in the birds’ extreme desert habitat, however, has increased by approximately 2 °C over the past 31 years, and their activity onset has advanced by 8.8 min across the past 11 summers. The authors therefore suggest that a ‘heat versus dark trap’ exists, pressuring diurnal desert endotherms in a changing climate.

Original reference: Proc. Biol. Sci. https://doi.org/10.1098/rspb.2025.0979 (2025)