Hot days are associated with short-term adrenocortical responses in a southern African arid-zone passerine bird.
Moagi, Lesedi L. Bourne, Amanda R. Cunningham, Susan J. Jansen, Raymond Ngcamphalala, Celiwe A. Ganswindt, André Ridley, Amanda R. McKechnie, Andrew E.
Moagi, Lesedi L.
Bourne, Amanda R.
Cunningham, Susan J.
Jansen, Raymond
Ngcamphalala, Celiwe A.
Ganswindt, André
Ridley, Amanda R.
McKechnie, Andrew E.
Citations
Altmetric:
Abstract
Relatively little effort has been directed towards elucidating the role of physiological stress pathways in mediating avian responses to global heating. For free-ranging southern pied babblers, Turdoides bicolor, daily maximum air temperatures (Tmax) between ∼35 and ∼40°C result in reduced foraging efficiency, loss of body mass and compromised breeding success. We tested the hypothesis that very hot days are experienced as stressors by quantifying relationships between Tmax and faecal glucocorticoid metabolite (fGCM) levels in naturally excreted droppings. On days when Tmax<38°C, fGCM levels were independent of Tmax (mean±s.d. 140.25±56.92 ng g−1 dry mass). At Tmax>38°C, however, fGCM levels increased linearly with
Tmax and averaged 190.79±70.13 ng g−1 dry mass. The effects of Tmax on fGCM levels did not carry over to the following morning, suggesting that very hot days are experienced as acute stressors.
Description
Date
2021-03-09
Journal Title
Journal ISSN
Volume Title
Publisher
The Company of Biologists
Research Projects
Organizational Units
Journal Issue
Keywords
Air temperature, Desert, Faecal glucocorticoid metabolites, Fitness costs, Heat stress