Assessing the sensitivity of avian species abundance to land cover and climate

Abstract

Climate projections for the Midwestern United States predict southerly climates to shift northward. These shifts in climate could alter distributions of species across North America through changes in climate (i.e., temperature and precipitation), or through climate‐induced changes on land cover. Our objective was to determine the relative impacts of land cover and climate on the abundance of five bird species in the Central United States that have habitat requirements ranging from grassland and shrubland to forest. We substituted space for time to examine potential impacts of a changing climate by assessing climate and land cover relationships over a broad latitudinal gradient. We found positive and negative relationships of climate and land cover factors with avian abundances. Habitat variables drove patterns of abundance in migratory and resident species, although climate was also influential in predicting abundance for some species occupying more open habitat (i.e., prairie warbler, blue‐winged warbler, and northern bobwhite). Abundance of northern bobwhite increased with winter temperature and was the species exhibiting the most significant effect of climate. Models for birds primarily occupying early successional habitats performed better with a combination of habitat and climate variables whereas models of species found in contiguous forest performed best with land cover alone. These varied species‐specific responses present unique challenges to land managers trying to balance species conservation over a variety of land covers. Management activities focused on increasing forest cover may play a role in mitigating effects of future climate by providing habitat refugia to species vulnerable to projected changes. Conservation efforts would be best served focusing on areas with high species abundances and an array of habitats. Future work managing forests for resilience and resistance to climate change could benefit species already susceptible to climate impacts.

Antagonistic, synergistic and direct effects of land use and climate on Prairie wetland ecosystems: Ghosts of the past or present?

“…Our findings suggest that climate change and recent climate may have a stronger influence than current land use on birds and while climate relationships are well documented, the additional effects of changes since the early 1900s constitute novel findings that merit further investigation as explained below. We initially predicted stronger land use effects (LeBrun et al, ; Scrimgeour & Kendall, ). This unexpected result could reflect the relatively low number of studies that have evaluated simultaneously climate change effects relative to those of land use.…”

“…Richness and abundance of birds were highest at sites where precipitation and temperature increased the most since the early‐mid‐1900s, consistent with previous studies (Skagen & Adams, ). Other studies indicate that climate plays an important role in determining abundance, but effects tend to be habitat‐ and species‐specific and may differ over a species' annual cycle and range (LeBrun et al, ; Lemoine, Bauer, Peintinger, & Böhning‐gaese, ; Stephens et al, ). As the earth is warming, some migratory birds are arriving from the south and nesting earlier in North America and Europe (Butler, ).…”

“…To test whether land use, water chemistry, current weather and climate, and climate change exert additive or interacting effects on biota, and whether specific functional groups of macroinvertebrates and birds are more vulnerable or resilient to land use, climate and climate change effects, we used mixed‐effects linear regression models (Zuur, Ieno, Walker, Anatoly, & Smith, ). If only additive effects of climate and land use exist, then negative effects of cropland area and positive effects of wetland abundance (LeBrun et al, ; Scrimgeour & Kendall, ; Stanton et al, ) on (a) invertebrate and bird richness, and (b) functional groups with more specialized diets and/or foraging habitats, will be the same across sites regardless of precipitation or temperature. Conversely, temperature and precipitation effects on invertebrates and birds will be the same across sites regardless if nearby cropland and wetland area varies.…”

“…However, excessive precipitation or long‐term increases in precipitation could reduce invertebrate richness by increasing nutrient levels and the incidence of eutrophic water bodies as a result of higher agricultural run‐off (McCormick et al, ). Furthermore, we predicted that (e) survey year and long‐term temperature and precipitation effects on both avian and macroinvertebrate communities would be modest compared with the negative effects of low grassland cover and wetland abundance at sites with intensive agriculture (LeBrun, Thogmartin, Thompson, Dijak, & Millspaugh, ; Scrimgeour & Kendall, ; Stanton, Morrissey, & Clark, ).…”

A hierarchical spatiotemporal analog forecasting model for count data

“…Contemporary issues in natural resource management such as climate change rely increasingly on quantitative forecasts at time scales ranging from seasonal to decadal (e.g., LeBrun, Thogmartin, Thompson, Dijak, & Millspaugh, ). There are great challenges when making such forecasts in a rapidly changing environment.…”