Species abundances and distributions are changing in response to changing climate and other anthropogenic drivers but how this translates into how well species can match their optimal climate conditions as they change is not well understood. Using a continental-scale 30-year time series, we quantified temporal trends in climate matching of North American bird species and tested whether geographical variation in rates of climate and land use change and/or species traits could underlie variation in trends among species. Overall, we found that species abundances and distributions are becoming more decoupled from climate as it changes through time. Species differences in climate matching trends were related to their ecological traits, particularly habitat specialization, but not to average rates of climate and land use change within the species’ ranges. Climatic decoupling through time was particularly prominent for birds that were declining in abundance and occupancy, including threatened species. While we could not discern whether climate decoupling causes or is caused by the negative population trends, higher climatic decoupling in declining species could lead to a feedback as birds experience increasing exposure to suboptimal climatic conditions.

物种丰度和分布正在发生变化，以响应不断变化的气候和其他人为驱动因素，但这如何转化为物种在变化时如何匹配其最佳气候条件尚不清楚。使用大陆尺度的 30 年时间序列，我们量化了北美鸟类气候匹配的时间趋势，并测试了气候和土地利用变化率和/或物种特征的地理变化是否可能是物种间趋势变化的基础。总的来说，我们发现随着时间的推移，物种丰度和分布与气候的关系越来越脱钩。气候匹配趋势的物种差异与其生态特征有关，特别是栖息地专业化，但不是物种范围内气候和土地利用变化的平均速率。随着时间的推移，气候脱钩对于数量和占有率下降的鸟类来说尤为突出，包括受威胁的物种。虽然我们无法辨别气候脱钩是否导致或由负种群趋势引起，但随着鸟类越来越多地暴露于次优气候条件，衰退物种中更高的气候脱钩可能会导致反馈。