Örjan Johansson

Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia

Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.

REVERSIBLE IMMOBILIZATION OF FREE-RANGING SNOW LEOPARDS (PANTHERA UNCIA) WITH A COMBINATION OF MEDETOMIDINE AND TILETAMINE-ZOLAZEPAM

Conservation and research of the elusive snow leopard (Panthera uncia) have been hampered by inadequate knowledge about its basic life history. Global positioning system (GPS) collars can provide useful information, but there has been limited information available on safe capture methods, drug doses, and efficacy for effective immobilization of free-ranging snow leopards. We describe a drug protocol using a combination of medetomidine and tiletamine-zolazepam for the chemical immobilization of free-ranging snow leopards. We also describe physiologic responses to immobilization drugs, including rectal temperature, heart rate, respiratory rate, and relative hemoglobin oxygen saturation (SpO2) recorded every 10 min. Our study was carried out in the Tost Mountains adjacent to the Great Gobi Desert, in southern Mongolia, between August 2008 and April 2012. Eighteen snow leopards were captured or recaptured with foot-snares on 42 occasions and anesthetized for marking with GPS collars. The snow leopards received on average (±SD) 0.020±0.04 mg/kg body mass medetomidine and 2.17±0.45 mg/kg tiletamine-zolazepam. The duration of ensuing anesthesia was 69±13 min, including an induction period of 10 (±4) min. Anesthesia was reversed with 4 mg (0.10±0.04 mg/kg) atipamezole administered intramuscularly. The mean value for SpO2 for the 37 captures where we could record physiologic values was 91±4. The SpO2 increased significantly during anesthesia (+0.06±0.02%/min), whereas rectal temperature (average 38.1±0.7 C/min, change −0.04±0.003 C/min), heart rate (average 97±9 beats/min, change −0.20±0.03 beats/min), and respiratory rate (average 26±6 breaths/min, change −0.11±0.03 breaths/min) decreased significantly. A dose of 80 mg tiletamine-zolazepam (2 mg/kg body weight) and 0.72 mg medetomidine (0.02 mg/kg body weight) safely immobilized all adult and subadult snow leopards (weight 25–45 kg) in our study. All measured physiologic values remained within clinically acceptable limits.

Chemical Immobilization of Free-ranging Fallow Deer (Dama dama): Effect of Needle Length on Induction Time

Abstract We evaluated impact of the needle length, sex, and body condition on chemical immobilization induction time in 50 (29 males and 21 females) free-ranging fallow deer (Dama dama) in Sweden, 2006–11. Induction time is probably the single most important factor when immobilizing free-ranging wildlife with the use of a remote drug-delivery system. Induction times should be short to minimize stress and risk of injury, and to ensure that immobilized animals can be found and clinically monitored as soon as possible. We measured the distance between the darting location and where we recovered the immobilized animal and also the time occurring between the two events. We used two types of needles: 2.0 × 30– or 2.0 × 40–mm barbed needles with side ports. The most important result is that a 10-mm-longer dart needle can reduce the retrieval time substantially (>20 min) until an animal is under monitoring. On average after the darting, the retrieval time decreased from 51 to 29 min and the distance decreased from 519 m from the darting location to 294 m. We suggest that a needle length of 40 mm is preferable for immobilization of wild fallow deer, especially for animals in over-average–to–fat body condition.

From VHF to Satellite GPS Collars: Advancements in Snow Leopard Telemetry

Snow leopards occur at low densities and inhabit an extremely inhospitable environment. Effectively studying a species like this is best done through the use of telemetry. The first telemetry studies of the snow leopard occurred in the 1980s and 1990s using VHF (very high frequency) technology. Although these VHF studies began to provide new insights into the ecology of snow leopards, it also had significant limitations and was far from the perfect tool. The advent of satellite-based telemetry in the 1990s, however, began to revolutionize research into the species. For the first time, and with increasing effectiveness, researchers were not obligated to gather data through arduous and often fruitless hours and days of fieldwork. Over time, the use of GPS (global positioning system) satellite collars became the norm, and they are increasingly accurate and sophisticated. They have enabled researchers to now gather vast amounts of high-quality data in time- and resource-efficient ways, and are less disruptive to the collared animal that earlier telemetry technology.