Age-dependent carry-over effects in a long-distance migratory bird

Abstract

Migratory birds usually respond to climate change by modifying breeding and/or wintering areas, as well as by reproducing earlier. In addition, changes in winter habitat use or breeding phenology could have important carry-over effects on subsequent breeding success. Here, we studied age- and sex-dependent carry-over effects from wintering to the breeding stage of a small aerial insectivorous long-distance migratory bird, the barn swallows ( Hirundo rustica ) breeding in Denmark during 1984–2013. First, we used stable isotope analyses combined with ringing recoveries to identify wintering areas. Second, we found that environmental conditions as inferred by Normalized Differential Vegetation Index (NDVI) have deteriorated at the wintering grounds. Third, we used confirmatory path analysis to quantify the indirect effect of winter conditions on subsequent breeding success. Females advanced onset of breeding, laid more eggs and raised more fledglings in the first brood when ecological conditions during the previous winter improved. This response was age dependent, since yearlings did not respond to this environmental cue but the response was increasingly stronger as females aged. Males showed a similar response to winter conditions, although not statistically significant. These results highlight the importance of studying carry-over effects within the context of climate change, especially in relation to age of individuals.

Not Singing in the Rain: Linking Migratory Songbird Declines With Increasing Precipitation and Brood Parasitism Vulnerability

“…Climate change may thus influence bird species on a broader scale, as geographic shifts in climate envelope may sometimes outweigh effects of local land management (Barbet-Massin et al, 2012;Sohl, 2014;Mantyka-Pringle et al, 2019). Other factors not captured in this study may also influence breeding bird populations, such as carry-over effects, which recent students have suggested are widespread and important in many bird species (Harrison et al, 2011;O'Connor et al, 2014) and can be sex-and age-specific (Saino et al, 2017;López-Calderón et al, 2019). Wintering area precipitation, habitat, and resources may thus influence arrival times and productivity of migratory songbirds on their breeding grounds (e.g., Marra et al, 1998;Robb et al, 2008;McKinnon et al, 2015;Akresh et al, 2019;López-Calderón et al, 2019).…”

“…Other factors not captured in this study may also influence breeding bird populations, such as carry-over effects, which recent students have suggested are widespread and important in many bird species (Harrison et al, 2011;O'Connor et al, 2014) and can be sex-and age-specific (Saino et al, 2017;López-Calderón et al, 2019). Wintering area precipitation, habitat, and resources may thus influence arrival times and productivity of migratory songbirds on their breeding grounds (e.g., Marra et al, 1998;Robb et al, 2008;McKinnon et al, 2015;Akresh et al, 2019;López-Calderón et al, 2019). For example, Eurasian blue tits (Cyanistes caeruleus) with higher winter food availability laid eggs earlier and exhibited higher chick fledging rates (Robb et al, 2008).…”

“…Global climate change is influencing birds' breeding ecology, geographic ranges, and migration phenology. Changing precipitation and temperature patterns affect birds directly as well as indirectly through their impacts on habitat, food resources, and other factors critical to avian life history strategies and population dynamics (Moss et al, 2001;Cotton, 2003;Niemuth et al, 2008;Knudsen et al, 2011;McDonald et al, 2012;López-Calderón et al, 2019). For example, precipitation declines on the breeding grounds of yellow-headed blackbirds (Xanthocephalus xanthocephalus) have been correlated with density declines and reproductive failure (Fletcher and Koford, 2004).…”

The Impact of Weather on the Behavior and Ecology of Birds

“…Climate change may thus influence bird species on a broader scale, as geographic shifts in climate envelope may sometimes outweigh effects of local land management (Barbet-Massin et al, 2012;Sohl, 2014;Mantyka-Pringle et al, 2019). Other factors not captured in this study may also influence breeding bird populations, such as carry-over effects, which recent students have suggested are widespread and important in many bird species and can be sex-and age-specific (Saino et al, 2017;López-Calderón et al, 2019). Wintering area precipitation, habitat, and resources may thus influence arrival times and productivity of migratory songbirds on their breeding grounds (e.g., Marra et al, 1998;Robb et al, 2008;McKinnon et al, 2015;López-Calderón et al, 2019).…”

“…Global climate change is influencing birds' breeding ecology, geographic ranges, and migration phenology. Changing precipitation and temperature patterns affect birds directly as well as indirectly through their impacts on habitat, food resources, and other factors critical to avian life history strategies and population dynamics (Moss et al, 2001;Niemuth et al, 2008;McDonald et al, 2012;López-Calderón et al, 2019). For example, precipitation declines on the breeding grounds of yellow-headed blackbirds (Xanthocephalus xanthocephalus) have been correlated with density declines and reproductive failure (Fletcher and Koford, 2004).…”