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Research article - Peer-reviewed, 2020

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

Rosamond, Kristen M.; Goded, Sandra; Soultan, Alaaeldin; Kaplan, Rachel H.; Glass, Alex; Kim, Daniel H.; Arcilla, Nico

Abstract

Few empirical studies have quantified relationships between changing weather and migratory songbirds, but such studies are vital in a time of rapid climate change. Climate change has critical consequences for avian breeding ecology, geographic ranges, and migration phenology. Changing precipitation and temperature patterns affect habitat, food resources, and other aspects of birds' life history strategies. Such changes may disproportionately affect species confined to rare or declining ecosystems, such as temperate grasslands, which are among the most altered and endangered ecosystems globally. We examined the influence of changing weather on the dickcissel (Spiza americana), a migratory songbird of conservation concern that is an obligate grassland specialist. Our study area in the North American Great Plains features high historic weather variability, where climate change is now driving higher precipitation and temperatures as well as higher frequencies of extreme weather events including flooding and droughts. Dickcissels share their breeding grounds with brown-headed cowbirds (Molothrus ater), brood parasites that lay their eggs in the nests of other songbirds, reducing dickcissel productivity. We used 9 years of capture-recapture data collected over an 18-year period to test the hypothesis that increasing precipitation on dickcissels' riparian breeding grounds is associated with abundance declines and increasing vulnerability to cowbird parasitism. Dickcissels declined with increasing June precipitation, whereas cowbirds, by contrast, increased. Dickcissel productivity appeared to be extremely low, with a 3:1 ratio of breeding male to female dickcissels likely undermining reproductive success. Our findings suggest that increasing precipitation predicted by climate change models in this region may drive future declines of dickcissels and other songbirds. Drivers of these declines may include habitat and food resource loss related to flooding and higher frequency precipitation events as well as increased parasitism pressure by cowbirds. Positive correlations of June-July precipitation, temperature, and time since grazing with dickcissel productivity did not mitigate dickcissels' declining trend in this ecosystem. These findings highlight the importance of empirical research on the effects of increasing precipitation and brood parasitism vulnerability on migratory songbird conservation to inform adaptive management under climate change.

Keywords

climate change; weather; grassland breeding birds; Monitoring Avian Productivity and Survivorship (MAPS); grazing; haying; dickcissel (Spiza americana); brown-headed cowbird (Molothrus ater)

Published in

Frontiers in Ecology and Evolution
2020, volume: 8, article number: 536769

Authors' information

Rosamond, Kristen M.
International Bird Conservation Partnership
Goded, Sandra
International Bird Conservation Partnership
Soultan, Alaaeldin
Swedish University of Agricultural Sciences, Department of Ecology
Kaplan, Rachel H.
Crane Trust
Glass, Alex
Southern Illinois University
Kim, Daniel H.
Crane Trust
Arcilla, Nico
University of Nebraska-Lincoln

Sustainable Development Goals

SDG13 Climate action

UKÄ Subject classification

Ecology

Publication Identifiers

DOI: https://doi.org/10.3389/fevo.2020.536769

URI (permanent link to this page)

https://res.slu.se/id/publ/108969