Significant shifts in latitudinal optima of North American birds

• 成果类型: Article
• 署名作者: Martins, Paulo Mateus; Anderson, Marti J.; Sweatman, Winston L.; Punnett, Andrew J.
• 署名单位: Massey University; Massey University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12376
• DOI: 10.1073/pnas.2307525121
• 发表日期: 2024-04-09
• 关键词: climate-change; range shifts; species responses; poleward shifts; density shifts; land-use; abundance; patterns; traits; distributions

摘要

Changes in climate can alter environmental conditions faster than most species can adapt. A prediction under a warming climate is that species will shift their distributions poleward through time. While many studies focus on range shifts, latitudinal shifts in species' optima can occur without detectable changes in their range. We quantified shifts in latitudinal optima for 209 North American bird species over the last 55 y. The latitudinal optimum (m) for each species in each year was estimated using a bespoke flexible non- linear zero- inflated model of abundance vs. latitude, and the annual shift in m through time was quantified. One- third (70) of the bird species showed a significant shift in their optimum. Overall, mean peak abundances of North American birds have shifted northward, on average, at a rate of 1.5 km per year (+/- 0.58 SE), corresponding to a total distance moved of 82.5 km (+/- 31.9 SE) over the last 55 y. Stronger poleward shifts at the continental scale were linked to key species' traits, including thermal opti-mum, habitat specialization, and territoriality. Shifts in the western region were larger and less variable than in the eastern region, and they were linked to species' thermal optimum, habitat density preference, and habitat specialization. Individual species' latitudinal shifts were most strongly linked to their estimated thermal optimum, clearly indicating a climate- driven response. Displacement of species from their historically optimal realized niches can have dramatic ecological consequences. Effective conserva-tion must consider within- range abundance shifts. Areas currently deemed optimal are unlikely to remain so.