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For decades, federal and state wildlife agencies have monitored sage-grouse populations across the American West. Understanding population declines helps inform management decisions regarding land use, hunting, and conservation. Over the past 55 years, populations have declined by almost 80%. Recent additions to this long-term study, published December of last year, updated a warning tool that flags populations experiencing both local perturbations that cause decoupling and decline in trends, but also identifies chronic warnings when lower than expected abundance puts populations at increased risk of disappearing. This study documented that, on average, these fragile populations take over 8 years to rebound, so preventing declines is key. But how do we determine the causes?

Habitat fragmentation, by events such as human development and wildfire, can lead to sage-grouse population declines. A study published by USGS researchers this summer revealed that in Oregon, larger, less fragmented habitats supported more grouse. After declines, these robust populations rebounded faster than small populations in isolated areas. Late last year, scientists from USGS and the Nevada Department of Wildlife also discovered that precipitation can boost sage-grouse populations, while drought caused declines. These results are also in line with attenuated associations observed between sage-grouse population trends and livestock indices under more mesic conditions. Overall, USGS research informs efforts to anticipate declines and prioritize populations in need of conservation action, as well as support large-scale sagebrush conservation initiatives.