Field Anesthesia of Least Weasels (Mustela nivalis nivalis) with Isoflurane

The aggressive and agile nature of weasels makes the use of inhalant anesthetics preferable to injectable agents because inhalant anesthetics generally reduce handling time, cause less stress and present no risk of delivering the drug into an unintended area. Here we report on the use of the inhalant anesthetic isoflurane in free ranging least weasels. We used a battery powered portable anesthesia unit (Uninventor 400 Anesthesia Unit, AgnTho’s AB, Sweden) to immobilize the animals in the field. The isoflurane liquid was filled in a syringe connected to a vaporizer where it mixed with air coming from an air pump. The animals inhaled the anesthetic first in a wooden chamber and then through a modified facial mask. Mean induction time in the anesthetic chamber was 4.8 minutes (± 0.3 SE) with a setting of 4% isoflurane. The anesthesia was maintained with the facial mask and a setting of 2% isoflurane. Mean recovery time was 16.4 minutes (± 2.1 SE) and mean recumbency time 40.7 minutes (± 2.9 SE). We anesthesized 9 animals, had no fatalities during anesthesia and all animals recovered quickly. One animal was found dead 11 days post-capture of undetermined cause. Isoflurane is safe and easy to use with the tested setting. However we were unsuccessful in monitoring the animals following their release and we therefore recommend further evaluation of the anesthetic. In addition, we recommend the use of a wooden anesthetic chamber with bedding to avoid the risk of hypothermia

Evaluating radical conservation futures: strategies for assessing the potential for Eurasian lynx in the Benelux countries

Tolerance of anthropic environment has allowed large carnivores to recolonize and to be reintroduced within Europe in the last forty years. This indicates that, even in areas where the return of large carnivores seems unlikely, their presence and establishment is possible, even in highly modified environments. In the current context of the return of large carnivores in Europe, there is a need for scientific conservation tools to assess the full potential and consequences of the return of large carnivores in Europe, and in particular to evaluate potential impact on game and livestock. Today, the return of the Eurasian Lynx (Lynx lynx) in areas where it has been absent for long periods is becoming increasingly probable, and this requires further investigations. Three main lines of research will be particularly important: the use of habitat by Eurasian Lynx, the effect of habitat on predation behavior, and potential sources of conflict with human populations. The research project will address fine scale habitat use, the effect of prey‘s spatial variation on Lynx predation behavior, the use of different statistical methods to estimate Lynx‘s viability in various habitats and landscape, and a review of current conflicts throughout Europe. Results should allow better understanding of the Lynx redeployment potentials in lowland Western Europ

Selection of bed-sites by roe deer Capreolus capreolus fawns in a boreal landscape

Bed-site selection by 19 radio-collared roe deer Capreolus capreolus fawns from seven family groups was studied during June-July 1998 in southeastern Norway. The habitat consisted of small agricultural fields surrounded by industrially exploited boreal forest. Within the forest, fawns selected bed-sites that offered greater concealment, higher vegetation and more canopy cover than random sites. No such selection was evident within the homogenous pasture on the fields. Bed-sites in fields offered greater concealment than those in the forest, where there were no detectable differences between stand age classes. Compositional analysis revealed a significant preference for bed-sites to be located in forest, although fields and bogs were often used. Within the forest, stands of all age classes were used. The broad use of habitats may either reflect that habitats were equally good, or it may be a strategy to increase the area a predator has to search in order to find a fawn

Selection of bed-sites by roe deer Capreolus capreolus fawns in a boreal landscape

Bed-site selection by 19 radio-collared roe deer Capreolus capreolus fawns from seven family groups was studied during June-July 1998 in southeastern Norway. The habitat consisted of small agricultural fields surrounded by industrially exploited boreal forest. Within the forest, fawns selected bed-sites that offered greater concealment, higher vegetation and more canopy cover than random sites. No such selection was evident within the homogenous pasture on the fields. Bed-sites in fields offered greater concealment than those in the forest, where there were no detectable differences between stand age classes. Compositional analysis revealed a significant preference for bed-sites to be located in forest, although fields and bogs were often used. Within the forest, stands of all age classes were used. The broad use of habitats may either reflect that habitats were equally good, or it may be a strategy to increase the area a predator has to search in order to find a fawn

Influence of a deer carcass on Coleopteran diversity in a Scandinavian boreal forest: a preliminary study

We tested the effect of a large ungulate carcass on boreal forest biodiversity by contrasting the local abundance and diversity of Coleoptera around a roe deer Capreolus capreolus carcass and in a control plot, between 8 August and 3 September 2003, in southern Norway. The two plots differed both in occurrence and richness of species, which were almost double at the carcass plot, although the diversity indices were similar. The higher evenness of the control plot compensated for its lower number of species, probably because the carcass plot was a disturbed area, colonized by many species, which were represented by few individuals. The number of beetles captured each day correlated positively with temperature at the control plot, but not at the carcass plot, indicating that the presence of an abundant and concentrated resource increased the local activity of Coleoptera. The carcass is likely to create a particular microclimate, which could partly buffer against extremes of air-temperature variation. These preliminary results indicate that ungulate carcasses have a significant ecological impact, which should be further investigated to improve the management and restoration of European boreal forest ecosystems

Soil and vegetation nutrient response to bison carcasses in Bialowieza Primeval Forest, Poland

Ungulate carcasses can have important effects on the surrounding soil and vegetation. The impact of six carcasses of European bison (Bison bonasus) was investigated for the first time in a natural temperate forest (Bialeowieza, Poland) by measuring soil and plant nutrient concentrations along a gradient extending from the centre of each carcass. Calcium concentration and pH were found to be higher at the centre of the carcass, decreasing towards the periphery. This effect lasted up to 7 years after the death of the animal. The concentration of most nutrients in the soil and plants varied irregularly, suggesting an effect of the carcass at its centre but the absence of a clear pattern of variation along the gradient. Concentrations of NO3- in the soil differed only at the 1-year old carcass, suggesting a fast turnover of nitrate in temperate forests. Our results show that the effects of large herbivore carcasses on soil and plant nutrient concentrations are not easily detectable in a temperate forest as in more homogeneous habitats, such as tundra and prairie. This may be due to the high activity of scavengers and nutrient recycling in the study area, but it may also be a consequence of a more complex and patchy interaction between nutrient availability and other limiting factors in temperate forests

Field Anesthesia of Least Weasels (Mustela nivalis nivalis) with Isoflurane

The aggressive and agile nature of weasels makes the use of inhalant anesthetics preferable to injectable agents because inhalant anesthetics generally reduce handling time, cause less stress and present no risk of delivering the drug into an unintended area. Here we report on the use of the inhalant anesthetic isoflurane in free ranging least weasels. We used a battery powered portable anesthesia unit (Uninventor 400 Anesthesia Unit, AgnTho’s AB, Sweden) to immobilize the animals in the field. The isoflurane liquid was filled in a syringe connected to a vaporizer where it mixed with air coming from an air pump. The animals inhaled the anesthetic first in a wooden chamber and then through a modified facial mask. Mean induction time in the anesthetic chamber was 4.8 minutes (± 0.3 SE) with a setting of 4% isoflurane. The anesthesia was maintained with the facial mask and a setting of 2% isoflurane. Mean recovery time was 16.4 minutes (± 2.1 SE) and mean recumbency time 40.7 minutes (± 2.9 SE). We anesthesized 9 animals, had no fatalities during anesthesia and all animals recovered quickly. One animal was found dead 11 days post-capture of undetermined cause. Isoflurane is safe and easy to use with the tested setting. However we were unsuccessful in monitoring the animals following their release and we therefore recommend further evaluation of the anesthetic. In addition, we recommend the use of a wooden anesthetic chamber with bedding to avoid the risk of hypothermia