Shifting avian spatial regimes in a changing climate

In the present era of rapid global change, development of early warnings of ecological regime shifts is a major focus in ecology. Identifying and tracking shifts in spatial regimes is a new approach with potential to enhance understanding of ecological responses to global change. Here, we show strong directional non-stationarity of spatial regimes identified by avian community body mass data. We do this by tracking 46 years of avian spatial regime movement in the North American Great Plains. The northernmost spatial regime boundary moved >590 km northward, and the southernmost boundary moved >260 km northward. Tracking spatial regimes affords decadal planning horizons and moves beyond the predominately temporal early warnings of the past by providing spatiotemporally explicit detection of regime shifts in systems without fixed boundaries. Highly mobile taxa, like birds, occupy ecosystems that lack fixed boundaries, and tracking how these spatial regimes respond to environmental change is difficult. Avian route data show the spatial regimes of Great Plains bird communities have shifted poleward and reorganized over the past 46 years.