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Author ORCID Identifiers
Dylan M. Osterhaus
https://orcid.org/0000-0002-9044-1090
Timothy F. Wright
https://orcid.org/0000-0003-2859-5360
Description
The data and code included herein may be used to recreate the analysis and figures included in the article "Migration Speed, Timing, and Long-Term Shifts in Age Structure in North American Passerines During Fall Migration." Migration is challenging for birds, particularly juveniles, who experience increased mortality. Conservation efforts that increase juvenile survival could support the recovery of depleted populations. Understanding where and when juvenile abundances peak during migration would help identify priority conservation locations. However, it is unknown whether the age structure of migrant communities shifts spatiotemporally during migration. To investigate, we analyzed age-related differences in migration speed and timing using 6,567,747 bird banding encounters, as variability in these traits could drive demographic shifts. We found adults generally migrate faster than juveniles, with timing differences tied to adult molt strategy. Our analyses reveal previously undocumented shifts in community demographics: the proportion of juveniles decreases at northerly latitudes and increases at southerly latitudes throughout migration. Over the past 53 years, the juvenile proportions have increased in the north and decreased in the south. Integrating these findings with stopover abundance data can inform targeted conservation efforts.
Document Type
Dataset
Publication Date
2026
Publisher
Dryad Data Repository
Keywords
Avian Migration, Migration Behavior, Migration Ecology, Passerine Biology, Age Structure
Disciplines
Biology | Ecology and Evolutionary Biology | Ornithology
Department / Organizational Unit
Department of Biology; Department of Fish, Wildlife, & Conservation Ecology
Copyright Statement
Public Domain / CC0, no rights reserved
Funder
White Sands Missile Range, Avian Migration Program at New Mexico State University funded by the U.S. Department of Agriculture National Institute of Food and Agriculture’s Hispanic Serving Institution Program, T&E Inc., Mesilla Valley Audubon Society, New Mexico Ornithological Society
Grant / Award Number
UDSA NIFA HSI Award #2022-77040-37638
Recommended Citation
Osterhaus, Dylan M.; Desmond, Martha J.; and Wright, Timothy F., "Data and Code from: Migration Speed, Timing, and Long-Term Shifts in Age Structure in North American Passerines During Fall Migration" (2026). Biology: Datasets. 1.
https://digitalcommons.nmsu.edu/biology-data/1
Comments
Dylan M. Osterhaus received his PhD in Biology from NMSU in Fall 2025.