Freeman, Marc TrevorCzenze, Zenon J.Schoeman, K.McKechnie, Andrew E.2021-04-122021-04-122020-08-04Freeman, M.T., Czenze, Z.J., Schoeman, K. et al. Extreme hyperthermia tolerance in the world’s most abundant wild bird. Scientific Reports 10, 13098 (2020). https://doi.org/10.1038/s41598-020-69997-7.2045-2322 (online)10.1038/s41598-020-69997-7http://hdl.handle.net/2263/79391The thermal tolerances of vertebrates are generally restricted to body temperatures below 45–47 °C, and avian and mammalian critical thermal maxima seldom exceed 46 °C. We investigated thermoregulation at high air temperatures in the red-billed quelea (Quelea quelea), an African passerine bird that occurs in flocks sometimes numbering millions of individuals. Our data reveal this species can increase its body temperature to extremely high levels: queleas exposed to air temperature > 45 °C increased body temperature to 48.0 ± 0.7 °C without any apparent ill-effect, with individual values as high as 49.1 °C. These values exceed known avian lethal limits, with tolerance of body temperature > 48 °C unprecedented among birds and mammals.en© The Author(s) 2020. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License.VertebratesBody temperaturesThermoregulationAvian lethal limitsAnimal physiologyEcophysiologyRed-billed quelea (Quelea quelea)Article