The yellow-billed cuckoo, endangered in the West, has nested in a wider range of habitats than expected, a new study finds.

The western population of the species – currently found only in New Mexico and Arizona – was thought to nest primarily near riverbeds and streams or riparian areas. But one study published in the Field Ornithology Journal observed the Yellow-billed Cuckoo in the arid foothills and mountains of southeastern Arizona, known as the “Sky Islands.”

“This is a significantly different habitat than previously known breeding habitats for western cuckoos, and the numbers we found are a significant addition to previously known numbers in Arizona in particular,” said Charles Drost, author of the study. and research zoologist at the U.S. Geological Survey’s Southwest Biological Science Center.

Scientists have been able to find evidence of significant numbers of cuckoos, but the bird population is still relatively small compared to its previous numbers. Once found from British Columbia to Mexico, yellow-billed cuckoos in the West have seen their population decline by as much as 95 percent, according to the USGS.