Abstract
Avian migratory processes are typically precisely oriented, yet vagrants are frequently recorded outside their normal range. Wind displaced vagrants often show corrective behaviour, and as an appropriate response is likely adaptive. We investigated the physiological response to vagrancy in passerines. Activation of the emergency life-history stage (ELHS), assessed by high baseline plasma corticosterone, is a potential mechanism to elicit compensatory behaviour in response to challenges resulting from navigational error, coupled with response to fuel load and flight. We compared circulating plasma corticosterone concentrations and body condition between three migratory groups in autumn: (1) wind displaced southwest (SW) vagrants and (2) long range southeast (SE) vagrants on the remote Faroe Islands, and (3) birds within the expected SW migratory route (controls) on the Falsterbo peninsula, Sweden. Vagrants were further grouped by those sampled immediately upon termination of over-water migratory flight and those already on the island. In all groups there was no indication of the activation of the ELHS in response to vagrancy. We found limited support for an increased rate of corticosterone elevation within our 3 min sample interval in a single species, but this was driven by an individual ELHS outlier. Fat scores were negatively correlated with circulating corticosterone; this relationship may suggest that ELHS activation depends upon an individual's energetic states. Interestingly, in individuals caught at the completion of an obligate long-distance flight, we found some evidence of corticosterone suppression. Although limited, data did support the induction of negative feedback mechanisms that suppress corticosterone during endurance exercise, even when fuel loads are low.
Original language | English |
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Article number | 22104 |
Journal | Scientific Reports |
Volume | 12 |
Issue number | 1 |
DOIs | |
Publication status | Published - 21 Dec 2022 |
Bibliographical note
AcknowledgementsThe Danish Council for Independent Research supported the MATCH project (1323-00048B) and the Danish National Research Foundation supported the Center for Macroecology, Evolution and Climate (DNRF96). JW acknowledges support from the Endowed Chair in Physiology, University of California, Davis. We are indebted to Sophie Ehnbom and all the staff at Falsterbo Bird Observatory for facilitating and assisting with fieldwork in Sweden (this is report no. 321 from Falsterbo Bird Observatory); Rachel Muheim for assistance in obtaining permits; Jens-Kjeld Jensen, Janus Hansen and colleagues at Copenhagen Ringing Center for their assistance; and residents of Nólsoy for permission to catch in their gardens. We would also like to thank Marilyn Ramenofsky for valuable feedback on the manuscript.
Data Availability Statement
All raw data files generated during this study are available from the corresponding author on reasonable request.Keywords
- Humans
- Corticosterone
- Animal Migration/physiology
- Seasons
- Wind
- Sweden
- Flight, Animal/physiology