Carry‐over effects provide linkages across the annual cycle of aNeotropical migratory bird, theLouisianaWaterthrushParkesia motacilla

Abstract

Population limitation models of migratory birds have sought to include impacts from events across the full annual cycle. Previous work has shown that events occurring in winter result in some individuals transitioning to the breeding grounds earlier or in better physical condition than others, thereby affecting reproductive success (carry‐over effects). However, evidence for carry‐over effects from breeding to wintering grounds has been shown less often. We used feather corticosterone (CORTf) levels of the migratory Louisiana Waterthrush Parkesia motacilla as a measure of the physiological state of birds at the time of moult on the breeding territory to investigate whether carry‐over effects provide linkages across the annual cycle of this stream‐obligate bird. We show that birds arriving on wintering grounds with lower CORTf scores, indicating reduced energetic challenges or stressors at the time of moult, occupied higher quality territories, and that these birds then achieved a better body condition during the overwinter period. Body condition, in turn, was important in determining whether adult birds returned the following winter, with birds in better condition returning at higher rates. Together these data suggest a carry‐over effect from the breeding grounds to the wintering grounds that is further extended with respect to annual return rates. Very few other studies have linked conditions during the previous breeding season with latent effects during the subsequent overwintering period or with annual survival. This study shows that the effects of variation in energetic challenges or stressors can potentially carry over from the natal stream and accumulate over more than one life‐history period before being manifested in reduced survival. This is of particular relevance to models of population limitation in migratory birds.

Diversification of a ‘great speciator’ in the Wallacea region: differing responses of closely related resident and migratory kingfisher species (Aves: Alcedinidae:Todiramphus)

“…Although wintering grounds have strong carry-over effects on breeding success (Bearhop et al 2004, Latta et al 2016, Rockwell et al 2017, and Sacred Kingfisher individuals are known to be faithful to the same wintering site (Woodall & Kirwan 2018b), the ability of the Sacred Kingfisher to adapt to its wintering grounds will be limited by the constraints placed upon the population by the demands of its breeding grounds and its migration route. The Sacred Kingfisher is found in mangrove habitat throughout the region, regardless of island size (but with the addition of the Collared Kingfisher as a potential competitor on smaller islands).…”

Wintering space use and site fidelity in a nomadic species, the snowy owl

“…Defined as the way individuals use environmental components to meet their life history needs (Block andBrennan 1993, Jones 2001), habitat use can be influenced by multiple factors during winter such as food abundance or its accessibility, which can be limited by environmental factors such as snow cover in winter (Greenwood andBaillie 1991, Golawski andKasprzykowski 2010). Despite such environmental variability, some migrating species will show relatively high fidelity to a specific wintering site because familiarity with a given site may improve foraging efficiency, predator avoidance or maintain a dominant status, which could ultimately increase individual fitness (Cresswell 2014, Blackburn and Cresswell 2016, Latta et al 2016. Site fidelity is generally favoured when resource levels are predictable in space and time (Newton 2006(Newton , 2008.…”

Biomarker of burden: Feather corticosterone reflects energetic expenditure and allostatic overload in captive waterfowl

“…Recent studies of COEs using CORT f from post‐breeding or wintering periods have found important relationships with subsequent individual condition, breeding performance and investment (Boves, Fairhurst, Rushing, & Buehler, ; Crossin et al., ; Harms et al., ; Kouwenberg, Hipfner, McKay, & Storey, ; Latta et al., ; Pérez et al., ). However, results have not been consistent (Bourgeon et al., ; Legagneux et al., ), possibly because prior history of energetic demands, which is unknown in many studies, may influence future CORT f values (e.g.…”