The breeding distribution of a migratory bird fluctuates with nonbreeding season rainfall over the last century

Species responses to climate change include shifts in distribution, abundance, and range limits. Predicting such shifts for migratory birds is inherently complex given the diversity of ways climate change can impact species throughout their annual cycles. For example, recent findings demonstrate that the breeding origin of a nonbreeding population of American Redstarts (Setophaga ruticilla) in Jamaica is shifting southward in response to prolonged drought on the nonbreeding grounds differentially causing lower survival in longer migrating individuals. Here, we examine how widespread this mechanism has operated over the past century and across the range of this species. We sampled tail feathers from redstart museum specimens and live birds from three time periods dating back to the turn of the 20th century from 5 regions across their nonbreeding range (Andean, Greater Antillean, Isthmian, Pacific Slope, and Yucatan) and used stable hydrogen isotopes to estimate changes in breeding origin..., , # Data from: The breeding distribution of a migratory bird fluctuates with nonbreeding season rainfall over the last century

Dataset DOI: [10.5061/dryad.37pvmcvwr](10.5061/dryad.37pvmcvwr)

## Description of the data and file structure

See Methods section of associated manuscript entitled \"The breeding distribution of a migratory bird fluctuates with nonbreeding season rainfall over the last century\". Note that some data used were originally published in Studds et al. (2021) and Dossman et al. (2023), referenced below.

### Files and variables

#### File: Ecoregions2017.dbf, Ecoregions2017.prj, Ecoregions2017.shp, Ecoregions2017.shx

**Description:** used to load shapefile of world ecoregions.

#### File: nonbreeding.cpg, nonbreeding.dbf, nonbreeding.prj, nonbreeding.shp, nonbreeding.shx

**Description:** used to load shapefile of American Redstart nonbreeding regions relevant to analysis originally derived from migratory connectivity estimates.

#### File: isotopeanalysis-GCB.R

**De...,