Analyses of fecal and hair glucocorticoids to evaluate short- and long-term stress and recovery of Asiatic black bears (Ursus thibetanus) removed from bile farms in China

Demand for traditional Chinese medicines has given rise to the practice of maintaining Asiatic black bears (Ursus thibetanus) in captivity to harvest bile. We evaluated hypothalamic-pituitary-adrenal (HPA) activity in Asiatic black bears on a bile farm in China by measuring cortisol in hair. We also monitored hair and fecal glucocorticoid metabolites as bears acclimated to improved husbandry at the Animals Asia Foundation China Bear Rescue Center (CBRC) after removal from other bile farms. Fecal samples were collected twice weekly for ~1 year, and hair was obtained from bears upon arrival at the CBRC and again ≥163 days later. Paired hair samples showed declines in cortisol concentrations of 12-88% in 38 of 45 (84%, p<0.001) bears after arrival and acclimation at the rehabilitation facility. Concentrations of cortisol in hair from bears on the bile farm were similar to initial concentrations upon arrival at the CBRC but were higher than those collected after bears had been at the CBRC for ≥163 days. Fecal glucocorticoid concentrations varied across months and were highest in April and declined through December, possibly reflecting seasonal patterns, responses to the arrival and socialization of new bears at the CBRC, and/or annual metabolic change. Data from segmental analysis of hair supports the first of these explanations. Our findings indicate that bears produced elevated concentrations of glucocorticoids on bile farms, and that activity of the HPA axis declined following relocation. Thus, hair cortisol analyses are particularly well suited to long-term, retrospective assessments of glucocorticoids in ursids. By contrast, fecal measures were not clearly associated with rehabilitation, but rather reflected more subtle endocrine changes, possibly related to seasonality.

Policies and management of overabundant deer (native or exotic) in protected areas

A workshop was convened in Chile in August 2010 as part of the 7th International Deer Biology Congress (IDBC). Its aim was to explore global differences in the policies and management of overabundant deer in protected areas. The main goal of the workshop was to provide South American researchers and managers with a snapshot of some of the approaches to management of deer overabundance used in a diverse array of case studies from North America, Europe, Australia and New Zealand. Various case studies were presented to illustrate the different methodological approaches in implementing deer control measures. Some general recommendations were formulated.

Effects of scale and logging on landscape structure in a forest mosaic

Landscape structure in a forest mosaic changes with spatial scale (i.e. spatial extent) and thresholds may occur where structure changes markedly. Forest management alters landscape structure and may affect the intensity and location of thresholds. Our purpose was to examine landscape structure at different scales to determine thresholds where landscape structure changes markedly in managed forest mosaics of the Appalachian Mountains in the eastern United States. We also investigated how logging influences landscape structure and whether these management activities change threshold values. Using threshold and autocorrelation analyses, we found that thresholds in landscape indices exist at 400, 500, and 800 m intervals from the outer edge of management units in our study region. For landscape indices that consider all landcover categories, such as dominance and contagion, landscape structure and thresholds did not change after logging occurred. Measurements for these overall landscape indices were strongly influenced by midsuccessional deciduous forest, the most common landcover category in the landscape. When restricting analyses for mean patch size and percent cover to individual forest types, thresholds for early-successional forests changed after logging. However, logging changed the landscape structure at small spatial scale, but did not alter the structure of the entire forest mosaic. Previous forest management may already have increased the heterogeneity of the landscape beyond the point where additional small cuts alter the overall structure of the forest. Because measurements for landscape indices yield very different results at different spatial scales, it is important first to identify thresholds in order to determine the appropriate scales for landscape ecological studies. We found that threshold and autocorrelation analyses were simple but powerful tools for the detection of appropriate scales in the managed forest mosaic under study.

Anesthesia in female white-tailed deer using Telazol and xylazine

Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean +/- SE dosages of 2.53+/-0.16 mg/kg Telazol and 0.69+/-0.05 mg/kg of xylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8+/-2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals.

The attractiveness of a liquid bait to white-tailed deer in the Central Appalachian Mountains, Virginia, USA

We determined the attractiveness of a bait composed of apple juice, apple odor, water, glycerin, and salt to captive white-tailed deer (Odocoileus virginianus) at the National Zoological Park Conservation and Research Center, Front Royal, Virginia, USA. Thirty-nine deer (three adult males, 20 adult females, eight male fawns, eight female fawns) were presented with the bait formulation in a 22-ha enclosure during January, February, and May 1994. Daily consumption, and the frequency of visits to bait dispensers and the frequency of drinking bouts were recorded. Overall consumption was greatest in May (P < 0.001). While adults and fawns visited bait dispensers equally often, fawns drank more frequently (P < 0.001).