View in EDS

Pacific Northwest birds have shifted their abundances upslope in response to 30 years of warming temperatures.

Saved in:
Bibliographic Details
Title: Pacific Northwest birds have shifted their abundances upslope in response to 30 years of warming temperatures.
Authors: Freeman, Benjamin G.1 (AUTHOR) bfreeman47@gatech.edu, Eyster, Harold N.2,3 (AUTHOR), Heavyside, Julian M.4 (AUTHOR), Yip, Daniel A.5 (AUTHOR), Mather, Monica H.6 (AUTHOR), Waterhouse, F. Louise7 (AUTHOR)
Source: Ecology. Sep2025, Vol. 106 Issue 9, p1-12. 12p.
Subjects: Global warming, Climate change, Species diversity, Altitudes, Baby birds, Empirical research
Geographic Terms: British Columbia, Canada
Abstract: Mountain species are predicted to respond to warming temperatures by moving to higher elevations that remain relatively cool. Species can track warming by shifting their entire distributions upwards (the "escalator to extinction" hypothesis) or by increasing in abundance in the upper portion of their elevational range while maintaining stable elevational limits (the "upslope lean" hypothesis). Alternatively, mountain species may not change their abundance or distribution despite climate change (the "persist‐in‐place" hypothesis). Here we evaluate these three contrasting hypotheses by analyzing responses of breeding forest bird species to three decades of warming in southwestern British Columbia, Canada. Consistent with the upslope lean hypothesis, species' optimum elevations (elevations of highest abundance) increased by an average of 126 m, approximately tracking upslope movements in temperature isotherms. In contrast, species' elevational range limits were stable on average, contra the escalator to extinction hypothesis. Many individual species had stable distributions and abundances, and species with upslope abundance increases typically maintained stable abundances within the lower elevation portions of their range. Taken together, most species in our study region appear to be responding neutrally or favorably to warming temperatures. Nevertheless, one mountain species, the Canada Jay, Canada's national bird, is declining and vulnerable to the escalator to extinction within our study region. Overall, we emphasize the importance of empirical data—and abundance data in particular—when evaluating mountain species' vulnerability to climate change. [ABSTRACT FROM AUTHOR]
Copyright of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Mountain species are predicted to respond to warming temperatures by moving to higher elevations that remain relatively cool. Species can track warming by shifting their entire distributions upwards (the "escalator to extinction" hypothesis) or by increasing in abundance in the upper portion of their elevational range while maintaining stable elevational limits (the "upslope lean" hypothesis). Alternatively, mountain species may not change their abundance or distribution despite climate change (the "persist‐in‐place" hypothesis). Here we evaluate these three contrasting hypotheses by analyzing responses of breeding forest bird species to three decades of warming in southwestern British Columbia, Canada. Consistent with the upslope lean hypothesis, species' optimum elevations (elevations of highest abundance) increased by an average of 126 m, approximately tracking upslope movements in temperature isotherms. In contrast, species' elevational range limits were stable on average, contra the escalator to extinction hypothesis. Many individual species had stable distributions and abundances, and species with upslope abundance increases typically maintained stable abundances within the lower elevation portions of their range. Taken together, most species in our study region appear to be responding neutrally or favorably to warming temperatures. Nevertheless, one mountain species, the Canada Jay, Canada's national bird, is declining and vulnerable to the escalator to extinction within our study region. Overall, we emphasize the importance of empirical data—and abundance data in particular—when evaluating mountain species' vulnerability to climate change. [ABSTRACT FROM AUTHOR]
ISSN:00129658
DOI:10.1002/ecy.70193