Winter raptor population trends and land use across Nevada, USA

Bird populations in North America have faced significant declines since the 1970s, particularly among arid land species. However, raptors are one of the few groups that have remained stable or are increasing. Raptors play vital roles in ecosystems and are often used as indicators of habitat quality and health. Nevada, USA, is home to various raptor species, including migratory and resident birds. We aimed to assess the distribution, status, trends, and land-cover use of wintering raptors within the state. Using volunteers and agency biologists, we completed road-based and boat surveys across Nevada. We used road-based surveys to generate state-wide density estimates for the 9 most common raptor species using distance sampling methodologies. We augmented the road surveys with data from boat surveys and stationary eBird counts to analyze land use and climate patterns for 10 raptor species using random forest models. From 2016 to 2025, the road surveys recorded 10,157 individuals across 23 species, the boat surveys added 1,067 individuals from 9 species, and we augmented with 2,647 individuals from 11 species from stationary eBird counts. We had sufficient observations to evaluate trends of 9 species. Our results indicated no significant declines in the populations of the 9 most common species over the past decade. Our findings suggest that most species prefer moderate to lower elevations with warmer year-round temperatures and less annual precipitation; however, this may be confounded by our survey methodology. The presence of shrubs in the surrounding landscape positively influenced many species. Conservation strategies should focus on preserving shrublands and ensuring robust prey availability. Continued monitoring and data collection are essential to evaluate long-term trends and address potential declines in specific species.