Rabbit tick sightings more likely with snowshoe hare cycle on the upswing (7 photos)

The snowshoe hare population in Nova Scotia is on the uptick, and with it so are sightings of the parasites. 

By some force of nature, snowshoe hare populations fluctuate in 10-year cycles, with rapid increases followed by a more gradual decline. The hare population bottomed out in Nova Scotia a few years ago, and is expected to soon be close to peaking.

Haemaphysalis leporispalustris, better known as the rabbit tick, is often seen in increased numbers when the rabbit population is high. 

The tick species is quite small, measuring about 3 mm in length when not engorged. Adults are a tan to reddish-tan colour, and as the name suggests, they mainly feed on rabbits 

Retired zoologist Andrew Hebda says it’s not uncommon to see the parasites along the edges of a rabbit’s ears. 

“Hares use their ears as air conditioners,” he says. “There is more blood going through, so more food for ticks.”

In addition to there being plenty of hosts available this year for ticks to latch onto, Hebda says the warm spring also worked in the ticks’ favour. 

“They are cold-blooded, so the warmer it is the faster they can move, also the faster they develop,” he says. 

While ticks prefer damp environments, Hebda says the lack of rain this spring could also be contributing to increased rabbit tick sightings. 

“With the very dry summer, the depth of vegetation cover may not be as great as normal, so they are being observed more frequently,” he says. 

Weather specialist behind Nova Scotia Weather Service Allister Aalders, confirms this past June was particularly dry and warm.

“June 2020 and June 2017 were the only two of the past five years when temperatures were slightly above seasonal,” he says. “And we only had 33 mm of rain which amounts to less than half the average rainfall we typically see in the month of June.”

Rabbit ticks are not viewed to be as threatening to humans as the blacklegged tick, as they do not carry Lyme disease. But Hebda says it’s still important to avoid their bites. 

“They do not carry Lyme disease, but to the best of my knowledge they have been recorded carrying other diseases elsewhere,” he says. 

On small animal hosts, large infestations of ticks have been reported to weaken and even kill if they consume enough blood to cause a deficiency. 

In an emailed statement, Seaforth wildlife rehabilitation centre Hope For Wildlife confirms it has received animals over the years that were in distress because of tick infestations. 

“The animals can become anemic,” says Hope for Wildlife founder Hope Swinimer. “So we do often get them in for treatment with the case is severe.”

Hebda also points to studies that have shown such infestations can reduce the fertility of the host during that season. 

If you come across any species of tick in Nova Scotia, the online citizen science tool eTick has a group of professionals who will identify the species for you. The submission is then logged on an interactive map. Since the program launched in Nova Scotia earlier this year, more than 550 ticks have been vetted.