ONTARIANS BEGAN

paying more attention to ticks in the early 1980s, when it was dis-

covered that Blacklegged Ticks could transmit Lyme Disease. By then, we knew that

there was a population of Blacklegged Ticks in Long Point Provincial Park, on the

north shore of Lake Erie. Park visitors were advised to tuck their pant legs into their

socks, spray with insect repellent, inspect themselves thoroughly after walking through

suspect habitats and watch out for a ring-shaped rash if they were bitten.

Outside southwestern Ontario, birders breathed a collective sigh of relief and let

their pant legs hang out; it was a southern Ontario problem. Four decades later, things

have changed. Factors such as climate change and reforestation are expanding the ge-

ographic ranges of ticks and the pathogens they carry. Ontario birders might do well

to similarly expand their knowledge of ticks.

In Ontario, there are at least 19 species of ticks, but only two are considered serious

vectors for transmitting diseases to humans: the Blacklegged Tick (or Deer Tick) and

the newly arrived Lone Star Tick. Of lesser concern are the American Dog Tick and the

Brown Dog Tick.

DOG TICKS

The American Dog Tick, also known as Wood Tick, is common in Ontario and is usually

found in grassy fields or along pathways. It can carry disease, such as Rocky Mountain

Spotted Fever, b

ut is not associated with Lyme Disease. Unfed, it is slightly smaller

than an un-popped kernel of corn. It is fairly easy to spot, even before engorgement, if

you take the time to look. But tick larvae and nymphs, which are much smaller than

adults, can also bite humans, though that is rare.

The Brown Dog Tick is similar to the American Dog Tick in appearance and infec-

tion-bearing potential. What is unique about this species is that it completes its entire

life cycle indoors, including in kennels; it is uncertain if it can survive in the wild

in Canada.

Clockwise from left:

This is a female American Dog Tick, which

engorges when feeding on blood.

While far less likely to feed on humans than

the Blacklegged Tick, the American Dog Tick

is still a concern. This is a male.

The Lone Star Tick is a new invader into

Ontario and birders should watch out for it,

despite its rarity so far. The female Lone Star

Tick gives this species its name, thanks to the

distinctive mark on its back.

Blacklegged Ticks (or Deer Ticks) have spread

throughout Ontario, and some are vectors for

Lyme Disease.

Look Out Below

Ticks are widespread in Ontario, including the Blacklegged

Tick, which carries the bacterium triggering Lyme Disease