CWHC – Quebec collaborates on a moose research project in Jamésie
Moose are large ruminants of the deer family that live in North America. The males are characterized by fan-flattened antlers, and can weigh up to 700 kg, making it the largest deer alive. With their long legs and long neck they are well adapted to find their diet (mainly branches, shoots and leaves of willow or birch, and aquatic plants) in their environment (boreal forests and mixed deciduous forests, fir birch, wetlands and marshes). Their widened hooves facilitate swimming and prevent them from sinking into soft ground (snow, bogs). Moose are found throughout much of Quebec, particularly in the eastern forests where high density of moose can have devastating impact on forest regeneration. The populations in moose in Quebec are generally healthy. Interestingly, this species appears to be favored by logging. That being said, our knowledge on the impacts (positive or negative) of cutting practices remains limited in the region of Jamésie.
A team from the Ministère des Forêts, de la Faune et des Parcs – Chibougamau office (MFFP), under the supervision of Vincent Brodeur, undertook a project to better understand this relationship. Benjamin Lamglait and Stéphane Lair of the CWHC – Quebec were invited to participate to the project as veterinarians to help Charles Jutras and Stéphane Rivard, two experienced MFFP technicians, with the anesthesia and the health assessment of the captured animals. The animals were approached using a helicopter piloted by Michael Vaugeois. For their safety and that of the handlers, the animals were subsequently anesthetized with a hypodermic rifle. The products used were highly concentrated anesthetics allowing the use of small darts that could be sent at long distances. Adult females captured in January 2018 were equipped with radio-collars. In addition, several morphometric data were taken. The tracking of animals with collars will allow the scientists to better understand the ecology and the behavior of these large mammals in the North of Quebec and this according to forestry practices. The moose examined appeared to be in good physical condition and were often accompanied by a fawn. One of the observations of interest was the presence of an infestations of low intensity in the majority of moose by winter ticks (the study area is located at the northern limit of the known range of this parasite). Intensity measurements and a semi-quantitative assessment of the severity of alopecia (hair loss) were done as part of a monitoring program for this parasite implemented by the MFFP.
The winter tick (Dermacentor albipictus) primarily attacks moose. In the fall, tick larvae cling to the animals; during the winter, they feed on the blood of their host and continue their development, in nymphs, then in adults. Ticks feed repeatedly during the winter, always on the same moose. After the end of the winter, females full of blood drop to the ground to lay eggs. The eggs hatch during the summer and the cycle start again. When present in large numbers, ticks can weaken the affected moose. In areas with more favorable environmental conditions, tens of thousands of ticks can be found on a single moose. The most noticeable clinical sign is hair loss, secondary to rubbing and scratching consecutive to the itching caused by tick bites. When heavily parasitized, moose are also weakened because of the significant blood loss induced by repeated tick feeding. The additional energy expenditure associated with excessive scratching and damaged fur coat, which leads to heat loss, is also responsible to the loss of moose condition. All of these signs can sometimes weaken the animal until death, especially in calves. In the province of Quebec, winter ticks have been detected in the Bas-Saint-Laurent since the years 2000. Ticks have been detected on moose in the Capitale-Nationale region since 2010. Even though infestation is presently of higher severity in areas south of the St. Lawrence River, the northward expansion of this parasite is underway. The causes of this expansion are not yet known, but the high density of moose in certain regions of southern Quebec and global warming are among the most frequently proposed hypotheses. This parasitism could have a significant negative impact on moose populations in Quebec, as is the case for populations in the northern United States.
The relatively high prevalence of this parasite in moose in the Jasémie region and anecdotal reports on the presence of this parasite suggest that the northward expansion of this parasite may extend beyond the 53rd parallel and could infect forest-dwelling caribou populations. For the moment, infestation levels seem rather low and seem to have a limited impact on animal health. Nevertheless this parasite and its impact on the moose populations are definitely to be watched.
Benjamin Lamglait and Stéphane Lair
CWHC – Quebec