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SUMMARY With rapid environmental change, shifts in migration timing are vitally important for maintaining population stability and have been widely documented. However, little remains known abouthowmigrants are driving these shifts and what factors may influence the effective utilization of these strategies, limiting our ability to accurately assess species- and population-level vulnerability to climate change. The Hudsonian godwit (Limosa haemastica) is an extreme long-distance migratory shorebird that has (1) previously shifted its population-level migration timing and (2) exhibits sex-specific morphological differences. Therefore, we combined over a decade of light-level geolocator tracking data from a single breeding population with a historical predictive model to assess on-going shifts in migration timing while determining the time-shifting strategies utilized by each sex. Surprisingly, we found that godwit departure and arrival timing rapidly shifted 6 days later from 2010-2023 with no differences in timing between the sexes. Despite this change in migration timing, the population has maintained an average migratory duration of 24 days, suggesting that godwits are driving shifts in arrival timing entirely by shifting their nonbreeding ground departure, something rarely documented in long-distance migrants. Yet, we also found that godwits are not shifting their migration timing in the direction predicted by our model, providing evidence that this response may not be adaptive. These results emphasize the urgent need for a more holistic approach to assessing the relative vulnerability of migratory species and the adaptiveness of changes in migration timing.
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This content will become publicly available on January 1, 2026
Genetic analysis of museum samples suggests temporal stability in the Mexican nonbreeding distribution of a neotropical migrant
Seasonal migration is highly labile from an evolutionary perspective and known to rapidly evolve in response to selective pressures. However, long‐distance migratory birds rely partially on innate genetic programs and may be constrained in their ability to alter their migratory behavior. We take advantage of recent advances in our ability to genotype historical DNA samples to examine the temporal stability of migratory connections between breeding and nonbreeding populations (i.e. migratory connectivity) and population‐level nonbreeding distributions in the Wilson's warblerCardellina pusilla, a long‐distance migratory songbird. By assigning historical and contemporary samples collected across the nonbreeding range to genetically distinct breeding clusters, we suggest that broad‐scale population‐level nonbreeding distributions within this species have remained largely consistent within Mexico from the mid‐1900s to the present day. These findings support the idea that the nonbreeding distributions of long‐distance migrants may remain stable over long time scales, even in the face of rapid environmental change.
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- PAR ID:
- 10587190
- Publisher / Repository:
- NA
- Date Published:
- Journal Name:
- Journal of Avian Biology
- Volume:
- 2025
- Issue:
- 1
- ISSN:
- 0908-8857
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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