Protected prairies still lose grassland bird species, study finds

A 16-year survey of 40 protected tallgrass prairie sites in western Minnesota reveals that grassland bird populations are declining even in conservation areas. Species such as the upland sandpiper and Savannah sparrow have become less common, and even generalists like mourning doves are affected. The study, published in Ecological Applications, suggests that unpredictable weather and other factors are undermining protection efforts.

The 16-year monitoring effort covered 40 protected sites across western Minnesota, including state parks, wildlife management areas, and private conservation easements. Researchers conducted repeated visits between 2008 and 2023, recording bird sightings and calls during summer breeding seasons. Across the 33 species tracked, the likelihood of detection fell by 22 percent over the study period.

The findings echo a landmark 2019 Cornell Lab of Ornithology analysis estimating that nearly 3 billion birds have vanished from the U.S. and Canada over the past half-century, with grassland species losing half their numbers since the 1970s. The Minnesota team is now examining habitat fragmentation, grassland extent, and temperature anomalies during breeding seasons as potential drivers of the losses.