High-resolution recording of foraging behaviour over multiple annual cycles shows decline in old Adélie penguins’ performance
Age-related variation in foraging performance can result from both withinindividual change and selection processes. These mechanisms can only be disentangled by using logistically challenging long-term, longitudinal studies. Coupling a long-term demographic data set with high-temporalresolution trac...
Published in: | Proceedings of the Royal Society B: Biological Sciences |
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Main Authors: | , , , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Royal Society (Great Britain)
2023
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Subjects: | |
Online Access: | http://hdl.handle.net/10261/309804 https://doi.org/10.1098/rspb.2022.2480 |
Summary: | Age-related variation in foraging performance can result from both withinindividual change and selection processes. These mechanisms can only be disentangled by using logistically challenging long-term, longitudinal studies. Coupling a long-term demographic data set with high-temporalresolution tracking of 18 Adélie penguins (Pygoscelis adeliae, age 4–15 yrs old) over three consecutive annual cycles, we examined how foraging behaviour changed within individuals of different age classes. Evidence indicated within-individual improvement in young and middle-age classes, but a significant decrease in foraging dive frequency within old individuals, associated with a decrease in the dive descent rate. Decreases in foraging performance occurred at a later age (from 12–15 yrs old to 15–18 yrs old) than the onset of senescence predicted for this species (9–11 yrs old). Foraging dive frequency was most affected by the interaction between breeding status and annual life-cycle periods, with frequency being highest during returning migration and breeding season and was highest overall for successful breeders during the chick-rearing period. Females performed more foraging dives per hour than males. This longitudinal, full annual cycle study allowed us to shed light on the changes in foraging performance occurring among individuals of different age classes and highlighted the complex interactions among drivers of individual foraging behaviour. We are grateful for financial support provided by the National Science Foundation (grants OPP-1543498 & 1935870) and NASA (grant no. 80NSSC19K0189). Peer reviewed |
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