Data from: Spatially heterogeneous impact of climate change on small mammals of montane California

Resurveys of historical collecting localities have revealed range shifts,
primarily leading edge expansions, which have been attributed to global
warming. However, there have been few spatially replicated community-scale
resurveys testing whether species' responses are spatially
consistent. Here we repeated early twentieth century surveys of small
mammals along elevational gradients in northern, central and southern
regions of montane California. Of the 34 species we analysed, 25 shifted
their ranges upslope or downslope in at least one region. However,
two-thirds of ranges in the three regions remained stable at one or both
elevational limits and none of the 22 species found in all three regions
shifted both their upper and lower limits in the same direction in all
regions. When shifts occurred, high-elevation species typically contracted
their lower limits upslope, whereas low-elevation species had
heterogeneous responses. For high-elevation species, site-specific change
in temperature better predicted the direction of shifts than change in
precipitation, whereas the direction of shifts by low-elevation species
was unpredictable by temperature or precipitation. While our results
support previous findings of primarily upslope shifts in montane species,
they also highlight the degree to which the responses of individual
species vary across geographically replicated landscapes.