MANHATTAN, Kan. (AP) — Two Kansas State University researchers have been awarded more than $540,000 to study why several grassland bird species are in steep decline.

The university says in a news release that assistant biology professor Alice Boyle and assistant statistics professor Trevor Hefley will spend three years identify the key reasons behind the population changes. Funding for their work comes from the National Science Foundation.

They'll study dickcissels, eastern meadowlarks and grasshopper sparrows using data that's been gathered at the Konza Prairie Biological Station. The 8,600-acre native tallgrass research area is jointly owned by the university and the Nature Conservancy.

The study will look at factors that include rainfall variability, grazing and grassland burning.