Publications

Species distribution models (SDMs) that are derived through inference have been used to provide important insights toward species distributions. Their inferences can be robust in relation to known presences, but SDMs have error rates that cannot be quantified with certainty. For large plant species with unique signatures and in sparsely vegetated habitats, object-oriented satellite image

Breeding success should increase with prior knowledge of the surrounding environment, which is dependent upon an animal’s ability to evaluate habitat. Prospecting for nesting locations and migratory stop-over sites are well-established behaviors among bird species. We assessed whether ducks in Suisun Marsh, California, USA, a brackish marsh, prospect for suitable wetlands in the week...

The U.S. Geological Survey Western Ecological Research Center’s Santa Cruz Field Station, Santa Cruz, California, has been funded by the U.S. Navy to continue monitoring a suite of intertidal black abalone sites at San Nicolas Island, California. The nine rocky intertidal sites were established in 1980 by Glenn VanBlaricom (then of the U.S. Fish and Wildlife Service) to study the...

Conversion and fragmentation of wildlife habitat often leads to smaller and isolated populations and can reduce a species’ ability to disperse across the landscape. As a consequence, genetic drift can quickly lower genetic variation and increase vulnerability to extirpation. For species of conservation concern, quantification of population size and connectivity can clarify the influence...

Drought, coupled with rising temperatures, is an emerging threat to many forest types across the globe. At least to a degree, we expect management actions that reduce competition (e.g., thinning, prescribed fire, or both) to improve growth of residual trees during drought. The influences of management actions and drought on individual tree growth may be measured with high precision using...

Black abalone Haliotis cracherodii Leach, 1814 are known to feed on drift plant macrodetritus moved about in the intertidal zone by waves and currents. Drift capture is a trait shared by at least several other abalone species. Drift materials are entrapped beneath the anterior foot and held for ingestion. The quantitative significance of feeding on entrapped drift macrodetritus for black...

The brown anole, Anolis sagrei, is a native species to the Caribbean; however, A. sagrei has invaded multiple parts of the USA, including Florida, Louisiana, Hawai’i and more recently California. The biological impacts of A. sagrei invading California are currently unknown. Evidence from the invasion in Taiwan shows that they spread quickly and when immediate action is not taken...

The first signs of sea star wasting disease (SSWD) epidemic occurred in just few months in 2013 along the entire North American Pacific coast. Disease dynamics did not manifest as the typical travelling wave of reaction-diffusion epidemiological model, suggesting that other environmental factors might have played some role. To help explore how external factors might trigger disease, we...

A hardy inhabitant of the subalpine zone of western North America, whitebark pine (Pinus albicaulis) is a keystone tree species in California’s subalpine forests, where it regularly defines the upper treeline in the Sierra Nevada, Cascade, Warner, and Klamath Mountains. Walking portions of the John Muir Trail in the southern Sierra Nevada, moving through extensive stands and mats of...

Respiratory disease is a key factor affecting the conservation and recovery of bighorn sheep (Ovis canadensis ) populations. Innovative, minimally invasive tools such as gene transcription–based diagnostics have the potential to improve our understanding of the broad range of factors that can affect the health of wild sheep. Evaluation of transcript levels for genes representative of...

The vast conifer forests of California’s Sierra Nevada range inspire awe and create lasting memories. The size and longevity of these trees make them seem both otherworldly and everlasting. Indeed, their grandeur is such that visitors may not appreciate how these forests are connected to the larger landscape, and so there is little understanding that something as common as a drought...

Despite extensive range overlap between Great Basin gopher snakes (Pituophis catenifer deserticola) and Greater Sage-Grouse (Centrocercus urophasianus) within sagebrush ecosystems, there are few documented predator–prey interactions between these species. Although gopher snakes have been observed preying on nests of other prairie grouse, studies that used video-monitoring at sage-grouse...