Winter foraging dynamics of woodland caribou in an artificial landscape

The data suggest that arboreal lichen biomass and/or bite size are primary factors influencing intake rate. Caribou did not increase bite rate to compensate for smaller bite sizes or decreased biomass. Forest management should enhance lichen production to maximize intake rates for woodland caribou

Generic preference and in-vivo digestibility of alectorioid arboreal lichens by woodland caribou

All caribou exhibited a strong preference (92%) for lichen in the multi-species Bryoria complex (range=87-99%).Preference for Bryoria may be a function of higher protein content, lower tensile strength, or differences in concentrations of secondary plant constituents

IMPACTS OF SUPPLEMENTAL FEEDING ON THE NUTRITIONAL ECOLOGY OF BLACK BEARS

Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas where no effort to reduce conifer damage occurred. Mass gains for bears captured twice were 153 ± 119 g/day (x̅± SD) in the fed areas and 12 ± 104 g/day in non-fed areas. Fat gain for bears in the fed areas was 42 ± 50 g/day and 4 ± 59 g/day in the non-fed areas. However, because age-specific body masses and fat content did not differ between the 2 areas, short-term pellet feeding probably has no long-lasting effect on bear condition or productivity. The diet of bears in the fed areas was 55 ± 22% pelleted feed, 7 ± 7% animal matter, and 38 ± 18% vegetation. The diet of bears in the non-fed areas was 13 ± 17% animal matter and 87 ± 17% vegetation. Grass and sedge composed the majority of vegetation consumed in both areas. The energy content of Douglas-fir (Pseudotsuga menziesii) and western hemlock ( Tsuga heterophylla) sapwood was more digestible (60-67%) than grasses and forbs (18-47%). Smaller bears (adult females and subadult males and females) may do most of the damage because sapwood harvesting rates minimize nutritional gain to larger adult males

The bear circadian clock doesn’t ‘sleep’ during winter dormancy

Most biological functions are synchronized to the environmental light:dark cycle via a circadian timekeeping system. Bears exhibit shallow torpor combined with metabolic suppression during winter dormancy. We sought to confirm that free-running circadian rhythms of body temperature (Tb) and activity were expressed in torpid grizzly (brown) bears and that they were functionally responsive to environmental light. We also measured activity and ambient light exposures in denning wild bears to determine if rhythms were evident and what the photic conditions of their natural dens were. Lastly, we used cultured skin fibroblasts obtained from captive torpid bears to assess molecular clock operation in peripheral tissues. Circadian parameters were estimated using robust wavelet transforms and maximum entropy spectral analyses

Diet Composition and Body Condition of Northern Continental Divide Grizzly Bears, Montana

From 2009–2013, we documented apparent population health by investigating food use and physiological condition of grizzly bears (Ursus arctos) in the Northern Continental Divide Ecosystem (NCDE), Montana.  We used stable isotope analysis upon hair and blood tissue to obtain information on percent terrestrial meat and plant matter in the diets of NCDE bears.  We also assessed body fat content of grizzly bears via bioelectrical impedance analysis.  Adult females used less meat compared to subadults and adult males (P < 0.0001).  Bears within regions on the southwestern, southern, and eastern periphery of the ecosystem consumed a significantly higher proportion of meat than those in the interior or northwestern periphery (P < 0.0001).  Diets of bears in the Whitefish Mountains and North and South Fork of the Flathead River were, on average, composed of 70% less meat than those on the East Front.  Adult males had significantly higher den entrance body fat contents than adult females and subadults (P < 0.0001).  Average body fat of adult females varied significantly between those in areas of high consumption of meat and those otherwise.  However, we find adult females across all regions enter dens at mean fat levels above those thought to be critical for cub production (i.e., > 20%).  We conclude that, within each region, the quantity and quality of foods appear adequate to meet the needs of reproductively-active adult females.  As truly opportunistic omnivores, grizzly bears in each region of the NCDE exploit diverse combinations of food items to arrive at productive body conditions

Sex Pheromone Responses of the Oriental Beetle (Coleoptera: Scarabaeidae)

The synthetic female sex pheromone of the oriental beetle, Anomala orientalis Waterhouse, was evaluated in the field and in a sustained-flight tunnel. In a 2-wk period, > 150,000 beetles were captured on three golf course fairways in Connecticut. Contrary to earlier reports that these beetles are most active during the warm, sunny portions of the day, we observed that peak activity occurs around sunset. Ten micrograms of either (Z)-7-tetradecen-2-one or an 89/11 (Z/E) blend on a rubber septum was found to be the minimum concentration with which no significant decrease in catch was observed in the field. There was no discrimination between Z and the blend at 1 μg and higher concentrations, but the E-isomer alone trapped significantly fewer beetles than either Z alone or the blend. These results are consistent with the flight tunnel data. The effects of temperature and light intensity on the mating behavior of A. orientalis also are discusse

Evidence for a Long-Lasting Compulsive Alcohol Seeking Phenotype in Rats

Excessive drinking to intoxication is the major behavioral characteristic of those addicted to alcohol but it is not the only one. Indeed, individuals addicted to alcohol also crave alcoholic beverages and spend time and put much effort into compulsively seeking alcohol, before eventually drinking large amounts. Unlike this excessive drinking, for which treatments exist, compulsive alcohol seeking is therefore another key feature of the persistence of alcohol addiction since it leads to relapse and for which there are few effective treatments. Here we provide novel evidence for the existence in rats of an individual vulnerability to switch from controlled to compulsive, punishment-resistant alcohol seeking. Alcohol-preferring rats given access to alcohol under an intermittent 2-bottle choice procedure to establish their alcohol-preferring phenotype were subsequently trained instrumentally to seek and take alcohol on a chained schedule of reinforcement. When stable seeking-taking performance had been established, completion of cycles of seeking responses resulted unpredictably either in punishment (0.45 mA foot-shock) or the opportunity to make a taking response for access to alcohol. Compulsive alcohol seeking, maintained in the face of the risk of punishment, emerged in only a subset of rats with a predisposition to prefer and drink alcohol, and was maintained for almost a year. We show further that a selective and potent μ-opioid receptor antagonist (GSK1521498) reduced both alcohol seeking and alcohol intake in compulsive and non-compulsive rats, indicating its therapeutic potential to promote abstinence and prevent relapse in individuals addicted to alcohol

The Candida albicans transcription factor Cas5 couples stress responses, drug resistance and cell cycle regulation

We thank Cowen lab members for helpful discussions. We also thank David Rogers (University of Tennessee) for sharing microarray analysis of the CAS5 homozygous mutant, and Li Ang (University of Macau) for assistance in optimizing the ChIP-Seq experiments. J.L.X. is supported by a Canadian Institutes of Health Research Doctoral award and M.D.L. is supported by a Sir Henry Wellcome Postdoctoral Fellowship (Wellcome Trust 096072). B.T.G. holds an Ontario Graduate Scholarship. C.B. and B.J.A. are supported by the Canadian Institutes of Health Research Foundation Grants (FDN-143264 and -143265). D.J.K. is supported by a National Institute of Allergy and Infectious Diseases grant (1R01AI098450) and J.D.L.C.D. is supported by the University of Rochester School of Dentistry and Medicine PREP program (R25 GM064133). A.S. is supported by the Creighton University and the Nebraska Department of Health and Human Services (LB506-2017-55). K.H.W. is supported by the Science and Technology Development Fund of Macau S.A.R. (FDCT; 085/2014/A2). L.E.C. is supported by the Canadian Institutes of Health Research Operating Grants (MOP-86452 and MOP-119520), the Natural Sciences and Engineering Council (NSERC) of Canada Discovery Grants (06261 and 462167), and an NSERC E.W.R. Steacie Memorial Fellowship (477598).Peer reviewedPublisher PD