North American bighorn sheep (Ovis canadensis) have experienced significant declines and population extirpations due to novel pathogens such as Mycoplasma ovipneumoniae. This disease continues to limit the population restoration of bighorn sheep. Therefore, understanding the demographic consequences of pathogen presence and the risk of contact between bighorn populations and potential...
The endangered Hawaiian common gallinule (Gallinula chloropus sandvicensis) is an endemic Hawaiian waterbird that occurs only on O‘ahu and Kaua‘i. Hanalei National Wildlife Refuge (NWR) supports the largest population of Hawaiian gallinule on either island and is also one of the highest producers of commercially grown taro in the state....
Fundamental objectives in the field of conservation biology involve understanding the processes that influence small and declining populations and applying that knowledge to develop appropriate monitoring strategies and targeted management and conservation actions. Critical first steps in determining the relative role of factors that drive population declines involves estimation of...
Pollination is an essential ecosystem service that sustains functioning ecosystems and aids in food production. In response to recent, widespread declines of managed and native bee populations, many land managers have shown interest in developing conservation and restoration plans for enhancing native bee habitat. However, there is a lack of...
Advances in mobile autonomous vehicles for oceanographic sensing provide new opportunities for passive acoustic monitoring of marine mammals. Acoustically equipped mobile autonomous platforms, including gliders, deep-water profiling floats, and drifting surface buoys can survey for a variety of marine mammal species over intermediate spatiotemporal scales. Additionally, such mobile platforms may...
Nearly all birds communicate through sound, and there has been much study of avian populations and communities using song and other vocalizations. Owls are no exception as they defend territories, advertise for mates, and defend against threats using various vocalizations. However, due to their generally nocturnal habits, some owl species...
One fundamental concern in conservation biology is species abundance. For many taxa, however, these data are costly to obtain via direct observation and thus limited in geographic or temporal scope. Very high-resolution satellite imagery provides a means to address these limitations and provide remotely-sensed counts of large, colonial species. We...
A fundamental objective of ecology and population biology is to identify factors that drive population dynamics and determine the population-level consequences of their interaction with the environment. Studies of reproductive performance can illuminate population dynamic processes, including the links between organismal biology, the environment, and life history theory. A central...
Informed conservation of small mammals, ecosystems, and predators requires a detailed understanding of how small mammals species and communities vary in both space and time, as well as the relative cyclicity and synchrony of this variation. This variation can be especially informative to land managers interested in manipulating the abundance...
Human alterations of landscapes take many forms, one of which is anthropogenic pollution. Mercury (Hg) is a complex contaminant because its uptake into the food web is not driven entirely by loading to the system; methylation is necessary to make Hg bioavailable and toxic to fish and wildlife. Because methylation...
In salmon-rich, northern coastal environments brown bears can occur at high densities and exert wide-ranging effects on ecosystem processes. Bear consumption of seasonally available fruit may provide important seed dispersal services to plants, and by extension, influence the ecology of seed consumers such as small mammals. In this study, we...
The Cackling goose (Branta hutchinsii minima) population has increased from a low of 20,000 in 1984 to the current population of 220,000-300,000 (Stehn 2012, Sanders 2013). As the Cackling goose population began to recover in the late 1990s, the majority of the population relocated from wintering in California to the...
Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern...
Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential...
It is critical for wildlife managers to understand the population dynamics of a harvested species, particularly for ungulates, which are a valuable wildlife resource. Due to concerns that mule deer (Odocoileus hemionus) populations in Oregon were declining, more comprehensive data on population vital rates and the factors potentially affecting them...
Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock...
In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon...
California's Central Valley agricultural landscapes provide several important wintering regions for Pacific Flyway sandhill crane (Grus canadensis) populations; however, the value of those regions is being compromised by urban expansion, other developments, and conversions to incompatible crop types. Greater (G. c. tabida) and lesser sandhill cranes (G. c. canadensis) both...
Energy development is expanding rapidly across the western US. Negative effects have been documented for some wildlife, but consequences of development are unclear for other taxa, including raptors. We had the opportunity to examine effects of oil and natural gas development on two raptor species of conservation concern, ferruginous hawks...