Working paper/research report

Publication year: 2022

DOI Link: https://doi.org/10.2139/ssrn.4254902

Abstract: 

A multitude of animal species undergo prolonged fasting events at regularly occurring life history stages. During such periods of food deprivation, individuals need to suppress their appetite. The satiety signalling gut hormone ghrelin has received much attention in this context in studies looking at mammalian systems. In wild birds, however, knowledge on the ghrelin system and its role during extended fasts is still scarce. In this study, we collected plasma samples for measurements of circulating ghrelin concentrations from adult southern rockhopper penguins (Eudyptes chrysocome chrysocome) during the 3 – 4 week long moult fast that they repeat annually to replace their feathers. We further sampled chicks before and after feeding bouts and non-moulting adults. Circulating ghrelin levels did not differ significantly between fed and unfed chicks but chicks had significantly lower plasma ghrelin levels compared to adults. Furthermore, penguins in late moult (i.e. individuals at the end of the prolonged fasting bout) had higher ghrelin levels compared to non-moulting adults. Our results show an upregulation of circulating ghrelin during moult and generally lower levels of ghrelin in chicks than in adults regardless of feeding state. Given the scarcity or absence of knowledge on the function of ghrelin in seabirds and in fasting birds in general, our results add greatly to our understanding of the avian ghrelin system.

Harvard Citation style: Slezacek, J., Quillfeldt, P., Kaiya, H. and Fusani, L. (2022) Appetite Regulation During Extended Fasting in Southern Rockhopper Penguins (Eudyptes Chrysocome Chrysocome). https://doi.org/10.2139/ssrn.4254902

APA Citation style: Slezacek, J., Quillfeldt, P., Kaiya, H., & Fusani, L. (2022). Appetite Regulation During Extended Fasting in Southern Rockhopper Penguins (Eudyptes Chrysocome Chrysocome). https://doi.org/10.2139/ssrn.4254902