Publications

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...

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...

Executive Summary The purpose of this report is to provide the Marine Corps with an annual summary of the distribution, abundance, and breeding activity of the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus; flycatcher) and to present results of management actions implemented to attract flycatchers and enhance flycatcher habitat at Marine Corps Base Camp Pendleton...

Drones are useful for wildlife research and management, but they can cause disturbance and harassment to wildlife. Sea otters (Enhydra lutris) are candidates for drone-based observation and monitoring but are vulnerable to disturbance. No studies have evaluated drone effects on sea otter behavior, but based on prior disturbance studies, we hypothesized: (1) sea otters would exhibit...

The giant gartersnake (Thamnophis gigas) is a semi aquatic snake endemic to the Central Valley of California. After losing 95 percent of its historic wetland habitat (Frayer and others, 1989), giant gartersnakes became state and federally listed as a threatened species (California Fish and Game Commission, 1971; U.S. Fish and Wildlife Service 1993, 1999). Continued monitoring of current

We compiled and verified a comprehensive inventory dataset of communication tower infrastructure across the range of the greater sage-grouse (Centrocercus urophasianus) and Gunnison sage-grouse (Centrocercus minimus), two species of conservation concern that are viewed as ecosystem health indicators for the entire sagebrush biome within the United States. Our dataset includes all known...

Noise exposure is a potential stressor for free-ranging marine mammals and is often studied in the absence of other environmental factors. Here, a multi-investigator, interdisciplinary effort was undertaken to examine the response of elephant seals to multiple stressors. An integrated physiological and ecological approach was taken, including immunology, stress physiology, toxicology...

A serious emerging threat to southern California riparian ecosystems is the invasive shot hole borer (Euwallacea spp.; SHB), a non-native beetle that cultivates a pathogenic fungus that kills trees of 66 reproductive host species. We examined the response of the bird community at the Tijuana River, California, to a massive SHB infestation in 2015 using data from a Monitoring Avian...

We assembled and annotated a chromosome-level genome for the Western Spadefoot, Spea hammondii (Anura, Scaphiopodidae) representing one of only three amphibians included in the California Conservation Genomics Project (CCGP). Spea hammondii is a vernal pool breeding anuran native to California and northwestern Baja California which has undergone both range contractions and local...

A parasite’s perceived societal impact depends on the disease it causes and the perception of the affected host species. For instance, doctors and veterinarians have a mission to treat parasites that infect humans or that impact host species that have some utilitarian or aesthetic value for society. Marine scientists have different concerns than doctors. Although the number of parasites...

We tracked 19 adult Galapagos Petrels Pterodroma phaeopygia during the chick-rearing seasons in 2009 and 2010 (Santa Cruz Island [n = 16] and Floreana Island [n = 3]) in the Galápagos Islands, Ecuador. Eight petrels performed 27 complete foraging trips lasting 0.6 to 18.8 days. Short trips (3.2 ± 2.1 days; 785 km; max displacement 671 km) and long trips (10.8 ± 3.9 days; 2,856 km; max...

Frequent and intense droughts are rapidly altering stand dynamics in western North American forests. The ecological and geographical diversity of northern California provides a unique opportunity to measure these responses across species, habitat types, and levels of competitive pressure. This study used dendrochronological techniques and linear mixed-effects models to assess growth...