A5075216172- Wildlife Ecology and Conservation
- Rangeland and Wildlife Management
- Fire effects on ecosystems
- Animal Ecology and Behavior Studies
- Ecology and biodiversity studies
- Species Distribution and Climate Change
- Wildlife-Road Interactions and Conservation
- Animal Behavior and Welfare Studies
- Fish Ecology and Management Studies
- Isotope Analysis in Ecology
- Genetic diversity and population structure
- melanin and skin pigmentation
- Ecology and Vegetation Dynamics Studies
- Biochemical Analysis and Sensing Techniques
- Environmental DNA in Biodiversity Studies
- Skin Protection and Aging
- Data-Driven Disease Surveillance
- Archaeology and Natural History
- Bat Biology and Ecology Studies
- Genetic and phenotypic traits in livestock
- Evolutionary Game Theory and Cooperation
- Bayesian Methods and Mixture Models
- Zoonotic diseases and public health
- Economic and Environmental Valuation
- Plant and fungal interactions
United States Geological Survey
2015-2024
Northern Rocky Mountain Science Center
2014-2024
Montana State University
2004-2011
Rocky Mountain Research (United States)
2004-2011
ABSTRACT During the past 2 decades, grizzly bear (Ursus arctos) population in Greater Yellowstone Ecosystem (GYE) has increased numbers and expanded range. Understanding temporal, environmental, spatial variables responsible for this change is useful evaluating what likely influenced demographics GYE where future management efforts might benefit conservation management. We used recent data from radio-marked bears to estimate reproduction (1983–2002) survival (1983–2001); these we combined...
Abstract Population fragmentation compromises population viability, reduces a species ability to respond climate change, and ultimately may reduce biodiversity. We studied the current state potential causes of in grizzly bears over approximately 1,000,000 km 2 western Canada, northern United States (US), southeast Alaska. compiled much our data from projects undertaken with variety research objectives including estimation trend, landscape fragmentation, habitat selection, vital rates,...
Abstract Grizzly bears ( Ursus arctos ) and American black U. americanus are sympatric in much of Yellowstone National Park. Three primary bear foods, cutthroat trout Oncorhynchus clarki ), whitebark pine Pinus albicaulis nuts, elk Cervus elaphus have declined recent years. Because park managers the public concerned about impact created by reductions these we quantified diets to determine how living near Lake adjusting. We estimated using: 1) stable isotope mercury analyses hair samples...
Abstract: During the past 2 decades, grizzly bear ( Ursus arctos ) population in Greater Yellowstone Ecosystem (GYE) has increased numbers and expanded its range. Early efforts to model mortality were principally focused within United States Fish Wildlife Service Grizzly Bear Recovery Zone, which currently represents only about 61% of known distribution GYE. A more recent analysis that explored one spatial covariate encompassed entire GYE suggested survival was highest National Park,...
For many years, the primary strategy for managing grizzly bears (Ursus arctos) that came into conflict with humans in Greater Yellowstone Ecosystem (GYE) was to capture and translocate offending away from sites. Translocation usually only temporarily alleviated problems most often did not result long-term solutions. Wildlife managers needed be able predict causes, types, locations, trends of conflicts more efficiently allocate resources pro-active rather than reactive management actions. To...
Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat- and protein-rich nuts are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years poor other years. Grizzly bear survival the Greater Yellowstone Ecosystem strongly linked to variation pine-nut availability. Because whitebark trees infected with blister rust (Cronartium ribicola), an exotic fungus has killed throughout much of its range northern Rocky...
Abstract We estimated grizzly bear ( Ursus arctos ) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 2009 by following radio‐collared females observing their fate reproductive performance. Our estimates of dependent cub yearling survival were 0.612 (95% CI = 0.300–0.818) 0.682 0.258–0.898). subadult adult female 0.852 0.628–0.951) 0.952 0.892–0.980). From visual observations, we a mean litter size 2.00 cubs/litter. Accounting...
ABSTRACT The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear ( Ursus arctos ) food resources recent decades. decline ungulates, fish, whitebark pine seeds Pinus albicaulis prompted questions regarding their ability to adapt. We examined body composition diet bears using bioelectrical impedance stable isotopes determine if 1) we can detect a change quality associated with either ungulates or pine, 2) combined resulted carrying...
When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained seasonal food availability, limits intake rate as body size increases, and competition. By visiting locations 37 individuals during 274 bear-days, we documented foods consumed grizzly (Ursus arctos) black bears americanus) in Grand Teton National Park 2004–2006. Based on...
Abstract Effective population size ( N e ) is a key parameter for monitoring the genetic health of threatened populations because it reflects population's evolutionary potential and risk extinction due to stochasticity. However, its application wildlife has been limited difficult measure in natural populations. The isolated well‐studied grizzly bears U rsus arctos Greater Yellowstone Ecosystem provides rare opportunity examine usefulness different estimators monitoring. We genotyped 729...
Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE) are opportunistic omnivores that eat a great diversity of plant and animal species. Changes climate may affect regional vegetation, hydrology, insects, fire regimes, likely influencing abundance, range, elevational distribution plants animals consumed by GYE grizzly bears. Determining dietary breadth is important to document future changes food resources how those nutritional ecology grizzlies. However, no synthesis...
Abstract For several decades, grizzly bear populations in the Greater Yellowstone Ecosystem ( GYE ) and Northern Continental Divide NCDE have increased numbers range extent. The population remains isolated although effective size has since early 1980s, genetic connectivity between these a long‐term management goal. With only ~110 km distance separating current estimates of occupied for populations, potential gene flow is likely greater now than it been many decades. We sought to delineate...
ABSTRACT Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly populations of conservation concern. Annual growth the grizzly bear ( Ursus arctos ) Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% 2002–2011. Substantial availability a key food source and density have occurred. Whitebark pine Pinus albicaulis ), seeds which are valuable but variable fall bears, experienced...
The US Fish and Wildlife Service (USFWS) proposed delisting the Yellowstone grizzly bear (Ursus arctos horribilis) in November 2005. Part of that process required knowledge most current distribution species. Here, we update an earlier estimate occupied range (1990–2000) with data through 2004. We used kernel estimators to develop maps habitats based on initial sightings unduplicated females (n = 481) cubs year, locations radiomarked bears 170), spatially unique conflicts, confrontations,...
Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen–Gill formulation (A–G) has seen limited application mark–resight data but a number advantages, including ability accommodate left-censored data, time-varying covariates, multiple events, discontinuous intervals risks. We introduce A–G structure interpretation results, assessment assumptions. then apply 22 years...
Changes in life history traits of species can be an important indicator potential factors influencing populations. For grizzly bears (Ursus arctos) the Greater Yellowstone Ecosystem (GYE), recent decline whitebark pine (WBP; Pinus albicaulis), fall food resource, has been paired with a slowing population growth following two decades robust increase. These observations have raised questions whether resource or density-dependent processes may associated changes growth. Distinguishing these...
Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed method to estimate amount of ingested by living Lake area. The utilized (i) relatively high, naturally occurring concentration mercury (508 ± 93 ppb) and its virtual absence all other bear foods ([Formula: see text]6 ppb), (ii) hair snares remotely collect from visiting spawning...
Abstract We studied survival and causes of mortality radiocollared cougars ( Puma concolor ) on the Greater Yellowstone Northern Range (GYNR) prior to (1987–1994) after wolf Canis lupus reintroduction (1998–2005) evaluated temporal, spatial, environmental factors that explain variation in adult, subadult, kitten survival. Using Program MARK multimodel inference, we modeled cougar based demographic status, season, landscape attributes. Our best models for adult independent subadults indicated...
Many parasites infect multiple hosts, but estimating the transmission across host species remains a key challenge in disease ecology. We investigated within and dynamics of canine distemper virus (CDV) grizzly bears (Ursus arctos) wolves (Canis lupus) Greater Yellowstone Ecosystem (GYE). hypothesized that may be more likely to exposed CDV during outbreaks wolf population because often displace while scavenging carcasses. used serological data collected from 1984 2014 conjunction with...
The Greater Yellowstone Ecosystem (GYE) supports the southernmost of 2 largest remaining grizzly bear (Ursus arctos) populations in contiguous United States. Since mid-1980s, this population has increased numbers and expanded range. However, concerns for its long-term genetic health remain because presumed continued isolation. To test power methods detecting immigrants, we generated 16-locus microsatellite genotypes 424 individual bears sampled GYE during 1983–2007. Genotyping success was...
We report on 3 cases of mixed-aged litters (young born in different years) brown bears (Ursus arctos); 1 instance the cub-of-the-year (hereafter called cubs) died den. Two occurred Sweden after mothers were separated from their young during breeding season. In one, mother was accompanying cub for at least 12.5 hours and possibly up to 3.3 days, later 4 days. other, her yearling times 1–14, 1–6 She with a male first separation. Specific events that produced litter observed Greater Yellowstone...