Final Report: Fitting the Climate Lens to Grassland Bird Conservation: Assessing Climate Change Vulnerability Using Demographically-Informed Species Distribution Models
The Earth is warmer today than it has been during most of the last 11,000 years; as warming trends approach unprecedented levels, there is little doubt that future climate change will have profound effects on species conservation and management. Grassland ecosystems and many grassland-dependent birds are particularly vulnerable to rapid shifts in climate variability and associated changes in drought and extreme weather events. For grassland birds, climate change is likely to exacerbate environmental threats such as habitat loss due to shifting agricultural practices and housing sprawl. Our goal was to identify how certain grassland bird species are sensitive to climate variability and which regions have the highest level of exposure to future climate change. To do so, we convened a core group of managers to identify vulnerable grassland bird species, developed models to estimate how climate change may impact future grassland bird populations, and identified how current grassland bird management and conservation might lessen the impacts of future climate change impacts. Using this approach, we successfully organized an initial meeting of managers and identified two species, Henslow's Sparrows and Bobolinks, as species that are of managerial interest and may be vulnerable to changes in temperature and precipitation. We uncovered an important climate-demography linkage for Henslow's Sparrows and Bobolinks: summer precipitation, and to a lesser degree, temperature positively affected nest success. We found that future climatic conditions— primarily changes in rainfall—will likely contribute to reduced population persistence and range contraction for many grassland birds. However, many of these future changes can be lessened through grassland management and conservation. Large grassland patches, the most common metric of grassland conservation, appear to moderate the effects of weather on grassland birds and could be an effective component of climate-change adaptation.