Seasonal macro-demography of North American bird populations revealed through citizen science monitoring

Avian population sizes fluctuate and change over vast spatial scales, but the mechanistic underpinnings remain poorly understood. A key question is whether spatial and annual variation in avian population dynamics is driven primarily by variation in breeding season recruitment or by variation in overwinter survival. We present a method using large-scale eBird citizen-science data to develop species-specific indices of net population change as proxies for survival and recruitment gain, based on twice-annual, rangewide snapshots of relative abundance in spring and fall. We demonstrate the use of these indices by examining spatially explicit annual variation in survival and recruitment gain in two well-surveyed nonmigratory North American species, Carolina Wren (Thryothorus ludovicianus) and Northern Cardinal (Cardinalis cardinalis). We show that, while interannual variation in both survival and recruitment gain is slight for Northern Cardinal, eBird abundance data reveal strong and geogra..., , , ## Seasonal macro-demography of North American bird populations revealed through citizen science monitoring

[https://doi.org/10.5061/dryad.69p8cz991](https://doi.org/10.5061/dryad.69p8cz991)

## Description of the data and file structure

This zip file contains underlying dataset, R script and R package that accompany the following project: Socolar, J., B. Galtbalt, A. Johnston, F. L. Sorte, O. Robinson, K. Rosenberg, and A. Dokter. 2024. Seasonal macro-demography of North American bird populations revealed through citizen science monitoring. Ecography.

The zipped folder (data_code) contains:   

* \"carwre.rds\" and \"norcar.rds\" - the bootstrapped abundance data for Carolina wren and Northern cardinal derived from eBird Basic Dataset (EBD). 
* \"tmax_winter-tmax_summer-swe.rds\" - the daymet weather dataset, extracted from: [https://developers.google.com/earth-engine/datasets/catalog/NASA_ORNL_DAYMET_V4](https://developers.google.com/earth-engine/datasets/catalog/NASA_ORNL_DAYMET_V4)
* \"...