The winter tick on moose, keep your eyes open
What is the winter tick?
The winter tick (Dermacentor albipictus) is a mite that mostly attacks moose. It differs from other ticks in terms of its impressive size (measuring up to 15 millimetres), which peaks towards the end of winter. Parasitism of moose by the winter tick is a natural phenomenon that occurs in many regions of Québec, but infestations are currently reported to be greater in the regions located along the St. Lawrence River.
Male (at left) and female (at right)
Adult female gorged with blood
The ticks lay their eggs on the ground between the end of May and the beginning of June, and the eggs hatch during the summer. The larvae are inactive for some time, but in the fall they begin to climb and adhere in clusters to vegetation, at a height of roughly 1.25 metres. They then transfer onto animals that pass close by. Once established on the animal, they feed off the host's blood and continue to develop, gradually transforming into nymphs and then adults. After mating, which takes place at the end of winter, the blood-filled females drop to the ground to lay their eggs, and die. The life cycle then begins again. Each tick lives on only one host animal, usually a moose.
Click to enlarge
Effects for moose
In years when infestations are significant, thousands of ticks may attack a single moose, causing problems for severely affected animals. Clinical signs generally become visible towards the end of winter (Februaryand March), and may take different forms:
- Abnormal behaviour
The animal begins to groom itself excessively, to try and stop the severe itching. Some individuals become less fearful of humans, and may appear lost orconfused. They may also stop eating, and wander outside their natural habitat.
- Weight loss and poor physical condition
- Hair loss and appearance of wounds
- Loss of blood
The cumulative effects of all these factors, combined with harsh weather conditions, can affect the health of the moose, making them more vulnerable to predators, poaching and road accidents. In some cases, severely affected animals may die. Young moose are particularly vulnerable.
Photo : Serge Simonneau
Can the winter tick AFFECT OTHER SPECIES?
The winter tick can attack other species of ungulates, but the moose appears to be the most severely affected.
The moose mating period (towards the end of September) coincides with the period during which tick larvae are most abundant. The moose move around more frequently during this period, increasing their risk of contracting the parasite.
In addition, the grooming habits of the moose are different and somewhat less effective than those of the white-tailed deer, for example, and the moose's reaction to the early signs of infestation tends to be delayed. Consequently, the ticks are present in larger numbers on the animal, and are more firmly attached, making it difficult to dislodge them.
Photo : Michel Mongeon, MRN
What are the risks to health?
Contrary to the black-legged tick (Ixodes scapularis), which can transmit the bacteria responsible for Lyme's disease (Borrelia burgdorferi) to humans, the winter tick does not carry diseases that can be transmitted to humans. In addition, meat from infested animals is fit for human consumption.
Photo : courtesy INSPQ - LSPQ
Some precautionary measures
Although cases of humans contracting winter ticks are rare and danger-free, some precautionary measures are nevertheless required when handling wild animal carcasses:
- Wear gloves, long clothing and closed shoes.
- Apply an insecticide to your clothing.
- Carry out a self-examination (body and clothing) after handling a carcass. You can destroy any ticks present on your clothing by placing the garments in a dryer, on a high-heat cycle.
- Keep pet animals away from carcasses or remains.
- Throw away or destroy carcass remains (untreated skin and hair) to limit the risk of spreading ticks to other animals.
- If you find a tick on your skin, contact your region’s Public Health Branch for information on how to remove it safely and effectively.
The Ministère is collecting information in some large game registration stations. Your collaboration is extremely valuable. We also invite you to report any sick wild cervids or cervids behaving abnormally, as quickly as possible.
To report a sick animal : SOS Poaching: 1 800 463-2191.