A5073923738- Wildlife Ecology and Conservation
- Isotope Analysis in Ecology
- Ecology and biodiversity studies
- Animal Behavior and Welfare Studies
- Rangeland and Wildlife Management
- Computational Drug Discovery Methods
- Physiological and biochemical adaptations
- Redox biology and oxidative stress
- Ruminant Nutrition and Digestive Physiology
- Animal Ecology and Behavior Studies
- Bat Biology and Ecology Studies
- Fish Ecology and Management Studies
- Adipose Tissue and Metabolism
- HER2/EGFR in Cancer Research
- bioluminescence and chemiluminescence research
- Military, Security, and Education Studies
- Security, Politics, and Digital Transformation
- Marine animal studies overview
- Cancer Immunotherapy and Biomarkers
- Melanoma and MAPK Pathways
- Genetic and phenotypic traits in livestock
- Species Distribution and Climate Change
- Central European and Russian historical studies
- Radiomics and Machine Learning in Medical Imaging
- Cancer Genomics and Diagnostics
Yale University
2020-2025
Washington State University
2012-2024
Vanderbilt University
2019-2022
Brigham and Women's Hospital
2022
Massachusetts General Hospital
2022
University of Pittsburgh
2022
Mitchell Institute
2022
Texas A&M University
2022
Emory University
2022
University of Kansas
2022
The potential use of stable-isotope analyses (δ 13 C and δ 15 N) to estimate bear diets was assessed in 40-day feeding trials using American black bears (Ursus americanus). Bear plasma red blood cells have half-lives ~4 days ~28 days, respectively. isotopic signature is linearly related that the diet, with exception adipose tissue, there no fractionation across tissues. Isotopic were used three populations: Pleistocene cave (U. speleaus) Europe, grizzly arctos horribilis) inhabiting Columbia...
Tannins are a diverse group of compounds which precipitate protein.The impact tannins on herbivory has been difficult to assess because diversity in tannin chemistry and animal physiology.We have evaluated the effects large ruminants (deer, sheep) using artificial diets containing well-defhred tannins, compared results those obtained with natural forages.The different condensed gallotannins herbivores related chemical stability tannins.Commercial tannic acid does not same as...
Mule deer ( Odocoileus hemionus ), domestic sheep Ovis aries and American black bears Ursus americanus ) were fed quebracho Schinopsis sp.) tannin to determine the contribution of salivary proteins nitrogen- fiber-digestive efficiencies metabolism. These values compared previously published for laboratory rats Rattus rattus prairie voles Microtus ochrogaster ). deer, bears, consuming this condensed produced tannin-binding that reduced fecal-nitrogen losses per unit ingested metabolism...
The energetic cost of grazing was measured using indirect calorimetry with a tracheotomized elk (Cervus elaphus nelsoni). eating herbaceous forage averaged 0.32 kcal/kg body weight/ hour, an increment 26% over standing costs. Forage intake quantified esophageal fistulated and mule deer (Odocoileus hemionus hemionus). Dry matter consumption rate mean bite size increased curvilinearly as functions biomass for both species. Asymptotic grass rates were 2.22 14.04 g dry matter/minute elk,...
Bears consuming wild fruits for fall energy accumulation are constrained by several factors, including intake rate, the physiological capacity of gastrointestinal tract, and metabolic efficiency gain in body mass. We measured these relationships through foraging feeding trials using captive black bears (Ursus americanus) grizzly arctos). Four fruit types covering a range sizes clustering were offered to determine effect density, size, presentation on rate. Intake rate (in grams per minute)...
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...
We explored multiple linkages among grey wolves (Canis lupus), elk (Cervus elaphus), berry-producing shrubs and grizzly bears (Ursus arctos) in Yellowstone National Park. hypothesized competition between whereby, the absence of wolves, increases numbers would increase browsing on decrease fruit availability to bears. After were reintroduced with a reduced population, we there be an establishment shrubs, such as serviceberry (Amelanchier alnifolia), which is major plant. also that percentage...
We examined the historical and current diets of brown bears (Ursus arctos) black (U. americanus) in Greater Yellowstone Ecosystem, Glacier National Park immediately adjacent areas national forests, Cabinet-Yaak mountains northwestern Montana northern Idaho, Blackfeet Flathead Indian reservations east south Park, Kenai Peninsula Alaska, southwestern states Colorado, New Mexico, Arizona. Dietary estimates are an essential first step understanding variation productivity density populations and,...
The tannin-binding specificity of salivary proteins in several mammals was investigated as a possible explanation for observed food habits. Moose (Alces alces) and beaver (Castor canadensis) produce that only bind the linear condensed tannins common their preferred foods, such willow, aspen, or birch. mule deer (Odocoileus hemionus), which has more generalized diet, produces branched-chain gallotannins, but not an ellagitannin. omnivorous black bear (Ursus americanus) all types tannins. In...
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...
Thermoregulatory responses of mule deer (Odocoileus hemionus hemionus) and elk (Cervus elaphus nelsoni) were analyzed for air temperatures outdoors between 2 34 °C in summer −38 +24 winter. Body differed species, seasons, ages. Surface skin varied with temperature, incident radiation, seasonal pelage. Respiratory rate water loss increased exponentially while exhaled sigmoidally as temperature increased. Expired volume logarithmically increasing respiratory rate. Cutaneous evaporation (grams...
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...
Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these in themselves insufficient differences population productivity and life histories, because they do not provide a direct measure of energetic value or nutritional composition complete diet. Here, we developed dynamic model integrating food habits information assess parameters brown bear (Ursus arctos) diets three interior ecosystems North America. Specifically, estimate average...
ABSTRACT Ursids are the largest mammals to retain a plantigrade posture. This primitive posture has been proposed result in reduced locomotor speed and economy relative digitigrade unguligrade species, particularly at high speeds. Previous energetics research on polar bears (Ursus maritimus) found costs were more than double predictions for similarly sized quadrupedal mammals, which could be of their or due adaptations Arctic marine existence. To evaluate whether representative terrestrial...
Growth rates, milk intake, and activity patterns of neonatal mule deer (Odocoileus hemionus) mountain goats (Oreamnos americanus) were compared, along with weight changes their mothers, to determine (i) the energetic costs trade-offs following hiding as strategies reduce predation (ii) whether any additional energy cost due is borne by neonate, mother, or both. Body weights neonates at 1 9 weeks age did not differ between species, but growth rates differed changed time. For first 4...
We hypothesized that there would be minimal dietary overlap between sympatric brown bears (Ursus arctos) and American black (U. americanus) relative to salmon (Oncorhynchus spp.) utilization when alternative foods (e.g., fruits) are abundant. To maximize the chance we reject this hypothesis, examined diets of known have visited streams. Species, sex, individual identification visiting streams were determined by DNA analysis hair feces collected in 2002–2004 along those Diets estimated from...
The ecological role of large predators in North America continues to spark heated public debate. Although brown bears (Ursus arctos L., 1758) and the salmon (genus Oncorhynchus Suckley, 1861) they feed on have declined many areas, Kodiak archipelago is famous for abundant salmon. Salmon generally been managed maximum sustained yield a fisheries sense, but those levels may be well below what necessary ecosystem productivity. Consequently, we used stable isotopes mercury accumulated hair...
The loss of aquatic subsidies such as spawning salmonids is known to threaten a number terrestrial predators, but the effects on alternative prey species are poorly understood. At heart Greater Yellowstone ecosystem, an invasion lake trout has driven dramatic decline native cutthroat that migrate up shallow tributaries Lake spawn each spring. We explore whether this amplified effect generalist consumer, grizzly bear, populations migratory elk summer inside National Park (YNP). Recent studies...