Contribution of the CWHC-Quebec to a research program on fishers in Abitibi-Témiscamingue
Louis Imbeau, professor at the Université du Québec en Abitibi-Témiscamingue (UQAT), is working on the impact of land use on the biology of American martens (Martes americana) and fishers (Pekania pennanti). As part of his research program, animals are captured and equipped with tracking collars to study their movements on the landscape. To do so, the animals must be anesthetized. Historically, animals have been anesthetized using a gas anesthesia machine. Although this method has proven to be safe and effective, its use is limited to areas accessible by logging roads; indeed, the anesthesia machine and the oxygen tanks are relatively heavy and therefore require the use of a vehicle. As part of his research project Nathan Chabaud, PhD student under the supervision of Louis Imbeau from the Chaire en Aménagement forestier durable à l’UQAT, transmitters will be installed on fishers during next winter. Since very few logging roads are opened during the winter period in this region, the research team would like to use a safe and rapid method of anesthesia requiring easily transportable equipment when traveling by foot or by snowmobiles. In order to evaluate an alternative to the current method, a pilot project was done in the field (Abitibi-Témiscamingue) in February 2020 with the collaboration of the CWHC-Quebec team. A “portable anesthesia” method was tested on several American martens and a fisher during this project, which was supported by the Ministère des Forêts, de la Faune et des Parcs, the UQAT, and the Fédération des Trappeurs Gestionnaires du Québec (FTGQ). The field team was composed of Pauline Suffice, Pierre Fournier, Karine Béland and Stéphane Lair. The animals were first captured in suitable cages, temporarily restrained in a fabric cone and anesthetized using sevoflurane, an anesthetic gas commonly used in veterinary medicine.
This anesthetic agent was administered directly in its liquid form in a simple assembly attached to a facemask, where it was then inhaled as vapor by the animals. Of mention, anesthesia with liquid sevoflurane without using a vaporizer is only safe at outside temperatures below the freezing point. At these temperatures, the liquid form of the anesthetic agent evaporates at effective concentrations, without exceeding the concentrations that could be dangerous. If used at warmer outside temperatures, it could be fatal because the concentration obtained could exceed the safety threshold.
The animals were kept in the fabric cone until the level of sedation was sufficient to allow safe handling, which was generally very rapid. Once asleep, the animals were examined and a subcutaneous identification microchip was injected. A tracking collar was also installed on the fisher. Different morphometric measurements, as well as several photographs of the animal, were also taken during anesthesia. Once the procedures were completed, the animal was kept warm, wrapped in a blanket as needed, until it was slightly reactive and then transferred to a cage for its full post-anesthesia recovery. When its behavior was deemed to be back to normal, which generally required only a few minutes, the animal was released in the same area where it was captured. The anesthesia events and recoveries were all uneventful. None of the animals experienced hypothermia during the procedures, despite outside temperatures down to -16°C, demonstrating that these two species of mustelids are very well adapted to harsh Canadian winters, despite their small size.
Thanks to the tracking collar, the movements of the fisher will be monitored for a period of approximately 12 months. Researchers have already appreciated that this fisher has moved over surprising distances, traveling up to 65 km from its capture site.
This pilot project demonstrated that the use of liquid sevoflurane, inhaled as vapor, is a safe and effective alternative for short-term anesthesia of fishers in winter conditions. This method is associated with very rapid induction and recovery times, which contributes to reduce the stress level of the animals and the risks of anesthetic complications. It is however essential to carefully monitor the vital signs of anesthetized animals in order to properly follow the depth of this anesthesia.
Karine Béland, Stéphane Lair CWHC-Quebec