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Western Ecological Research Center (WERC)

The Western Ecological Research Center (WERC) is a USGS Ecosystems Mission Area operation serving primarily California and Nevada. WERC scientists work closely with Federal, State, academic, and other collaborators to address a diverse array of high-profile topics. Topics include research on effects of wildfire, sea level rise, drought, energy development and more on federal Trust species.

News

A Tale of Two Islands and the Future of an Ocean Sentinel Seabird

A Tale of Two Islands and the Future of an Ocean Sentinel Seabird

Causal Analysis of Fire Regime Drivers

Causal Analysis of Fire Regime Drivers

Tree rings provide an important multi-century context for the current wildfire crisis

Tree rings provide an important multi-century context for the current wildfire crisis

Publications

Distribution, abundance, and breeding activities of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the San Dieguito River and upper San Luis Rey River, San Diego County, California—2025 data summary Distribution, abundance, and breeding activities of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the San Dieguito River and upper San Luis Rey River, San Diego County, California—2025 data summary

Executive Summary We surveyed for Southwestern Willow Flycatchers (Empidonax traillii extimus; flycatcher) at the San Dieguito River and the upper San Luis Rey River in 2025. Surveys were completed at five locations: one along the San Dieguito River (San Dieguito [SD]), which was last surveyed in 2016, and four along the upper San Luis Rey River, including three downstream from Lake...
Authors
Scarlett L. Howell, Barbara E. Kus

Black abalone surveys at Naval Base Ventura County, San Nicolas Island, California—2023 annual report Black abalone surveys at Naval Base Ventura County, San Nicolas Island, California—2023 annual report

The U.S. Geological Survey monitors a suite of intertidal black abalone (Haliotis cracherodii) sites at San Nicolas Island, California, in cooperation with the U.S. Navy, which owns the island. The nine rocky intertidal sites were established in 1980 to study the potential effect of translocated sea otters on the intertidal black abalone population at the island. The sites were monitored...
Authors
Michael C. Kenner, Julie L. Yee

Effects of repeat prescribed burning in dry coniferous forests in national parks of California Effects of repeat prescribed burning in dry coniferous forests in national parks of California

Background Prescribed fire is a common approach to reduce fuels and mitigate fire hazards. The accumulation of live and dead fuels following initial treatment means that repeated application of prescribed fire could be used to maintain this benefit. However, the effect of repeated prescribed fires is not well documented in many dry coniferous forests in the western United States. Here...
Authors
Phillip J. van Mantgem, Micah C. Wright, Calvin A. Farris, Eamon Engber, Emma J. McClure, Anthony C. Caprio, MaryBeth Keifer

Science

Science for management of America’s iconic wild horses and burros

Wild horses and burros are iconic wildlife of the western USA as well as a complicated management issue on tribal, state, and federal lands. Due to their history as domesticated animals, these wild equids – also called “free-roaming” or “feral” equids – can reproduce quickly, and have few natural predators, allowing their populations to grow rapidly if not managed. When populations are too large...
Science for management of America’s iconic wild horses and burros

Science for management of America’s iconic wild horses and burros

Wild horses and burros are iconic wildlife of the western USA as well as a complicated management issue on tribal, state, and federal lands. Due to their history as domesticated animals, these wild equids – also called “free-roaming” or “feral” equids – can reproduce quickly, and have few natural predators, allowing their populations to grow rapidly if not managed. When populations are too large...
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Greater Sage-Grouse Population Monitoring Framework: Cheat Sheet

The Greater Sage-grouse Population Monitoring Framework fills a prominent information gap to help inform current assessments of sage-grouse population trends at nested spatial and temporal scales. It is centered on four objectives: (1) create a standardized database of lek counts; (2) develop biologically based spatial population structures by clustering leks; (3) estimate spatial trends at...
Greater Sage-Grouse Population Monitoring Framework: Cheat Sheet

Greater Sage-Grouse Population Monitoring Framework: Cheat Sheet

The Greater Sage-grouse Population Monitoring Framework fills a prominent information gap to help inform current assessments of sage-grouse population trends at nested spatial and temporal scales. It is centered on four objectives: (1) create a standardized database of lek counts; (2) develop biologically based spatial population structures by clustering leks; (3) estimate spatial trends at...
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Greater Sage-Grouse Population Monitoring Framework: Targeted Annual Warning System Information Sheet

The Greater Sage-grouse Population Monitoring Framework helps fill a major information gap to aid current assessments of sage-grouse population trends across spatial and temporal scales. It centers on four objectives: 1) create a standardized database of lek counts; 2) cluster leks to develop spatial population structures; 3) estimate spatial trends across temporal extents; and 4) develop a system...
Greater Sage-Grouse Population Monitoring Framework: Targeted Annual Warning System Information Sheet

Greater Sage-Grouse Population Monitoring Framework: Targeted Annual Warning System Information Sheet

The Greater Sage-grouse Population Monitoring Framework helps fill a major information gap to aid current assessments of sage-grouse population trends across spatial and temporal scales. It centers on four objectives: 1) create a standardized database of lek counts; 2) cluster leks to develop spatial population structures; 3) estimate spatial trends across temporal extents; and 4) develop a system...
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