The endocrine mechanism regulating stopover refueling and departure in avian migrants

• Applicant: Cas Eikenaar, Ph.D.
• Subject Area: Sensory and Behavioural Biology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 323729697

In birds successful completion of migration and timely arrival at the breeding or wintering grounds requires rapid refueling at stopover sites and departing from stopover at the appropriate time. Whereas the factors influencing the rate of refueling and departure from stopover are well known, our understanding, and even identification, of the physiological mechanism(s) involved in these crucial processes is very limited. I propose to substantially increase the limited knowledge of the endocrine mechanisms involved in refueling and departure from stopover, key behaviors of avian migration. First, by manipulating circulating corticosterone level I will test the causality of the correlations observed between corticosterone and both refueling rate and stopover departure likelihood. Second, I will investigate whether the hormone ghrelin is involved in up-regulating corticosterone level in migrants that are ready to depart. Specifically, I will determine whether a) corticosterone and ghrelin levels are positively correlated in migrants at stopover, and b) ghrelin levels increase towards departure from stopover.

• DFG Programme: Research Grants