1. Plasma mammalian leptin analogue predicts reproductive phenology, but not reproductive output in a capital‐income breeding seaduck.
- Author
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Hennin, Holly L., Legagneux, Pierre, Gilchrist, H. Grant, Bêty, Joël, McMurtry, John P., and Love, Oliver P.
- Subjects
LEPTIN ,ADIPOKINES ,SEA ducks ,GENE expression ,PEPTIDE hormones - Abstract
To invest in energetically demanding life history stages, individuals require a substantial amount of resources. Physiological traits, particularly those related to energetics, can be useful for examining variation in life history decisions and trade‐offs because they result from individual responses to environmental variation. Leptin is a protein hormone found in mammals that is proportional to the amount of endogenous fat stores within an individual. Recently, researchers have confirmed that a mammalian leptin analogue (MLA), based on the mammalian sequence of leptin, is present with associated receptors and proteins in avian species, with an inhibitory effect on foraging and body mass gain at high circulating levels. While MLA has been both quantified and manipulated in avian species, little is currently known regarding whether plasma MLA in wild‐living species and individuals is associated with key reproductive decisions. We quantified plasma MLA in wild, Arctic‐nesting female common eiders (Somateria mollissima) at arrival on the breeding grounds and followed them to determine subsequent breeding propensity, and reproductive phenology, investment, and success. Common eiders are capital‐income breeding birds that require the accumulation of substantial fat stores to initiate laying and successfully complete incubation. We found that females with lower plasma MLA initiated breeding earlier and in a shorter period of time. However, we found no links between plasma MLA levels and breeding propensity, clutch size, or reproductive success. Although little is still known about plasma MLA, based on these results and its role in influencing foraging behaviors and condition gain, plasma MLA appears to be closely linked to reproductive timing and is therefore likely to underlie trade‐offs surrounding life history decisions. We measured a plasma mammalian leptin analogue (MLA), a trait shown to influence foraging behaviour and mass gain, in wild‐living, pre‐laying female common eiders. We found that females with higher plasma MLA could reproduce at an earlier date and in a shorter period of time compared to females with lower plasma MLA, but other reproductive traits were not influenced. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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