January 28, 2025 

A temperature variation of one or two degrees might not feel like much to us humans, but to an Eastern Meadowlark trying to raise its nestlings, even slight temperature variations can have a big impact. 

As a Midwest Climate Adaptation Science Center Graduate Fellow, Dr. Jacy Bernath-Plaisted of the University of Wisconsin-Madison explored how microclimates – specific climates of small areas that are influenced by variations in vegetation and topography – inform how vulnerable grassland songbirds are to climate change. Grassland birds like the Eastern Meadowlark are among the most quickly declining bird species in North America, making it all the more important that we understand these vulnerabilities.     

Using fine-resolution models of near-surface temperature and humidity in grasslands, the research team found that rather than choosing nest sites according to preferable microclimates, such as areas with denser vegetation that may buffer high temperatures, grassland bird species were often constrained by habitat preferences. Grassland obligate species – birds that exclusively nest in grasslands, such as the Eastern Meadowlark – were less successful as microclimate temperatures increased. However, facultative generalists – birds that are more flexible in selecting their nesting sites, such as the Red-winged Blackbird – were not as strongly impacted by changes in temperature, because they could nest in wetlands or other habitats with more preferable microclimates. 

Read the article in Biology Letters. 

Watch a presentation by Dr. Bernath-Plaisted on this research: