Lyme Borreliosis in British Columbia

U R Visitor

"All you need is ignorance and confidence; then success is sure."

Mark Twain

IS THE DECLINING HARE POPULATION A FACTOR IN PASSING INFECTION TO HUMANS?

These observations encompass a small area in Central British Columbia. Map

Alton Myers letter shows the extent of hare populations in the 20's and 30's. Others have mentioned walking on rabbit trails in the wintertime without snowshoes and the stench in the bush in the spring after a die-off which currently happens approximately every ten years. This letter shows the breeding capabilities of the rabbits in this area when unmolested.

There is an often overlooked point that I would like to make here. Alton's letter reflects what was taught to me and most locals knew that the rabbits died every seven years. Trapping records show quite clearly a ten year cycle. I feel that the knowledge of the seven year cycle passed on to us by the native people should not be discounted when trying to understand the cyclic hare die off.

The first moose was sighted in the area in 1920, then the deer became very scarce. The deer and moose share a tick in this area. Did the moose bring a tick-borne disease which the deer have recovered from but the rabbits have not?

Old timers tell me the first lynx tracks were seen in the area in 1944. The rabbits are the main food source of the lynx.Did the lynx introduce a tick-borne disease that the rabbits have not recovered from?

"The lynx lives on rabbits, thinks rabbits, tastes like rabbits, increases with them, and on their failure, dies of starvation in the unrabbited woods".

Ernest Thompson Seton, 1912
There are other reasons that could explain the decreasing hare population. This phenomena has occurred in my lifetime, being able to see evolution happen this fast makes me wonder if man has been involved. We know of the propensity of the rabbit tick to attach to birds, what would happen if a bird and ticks flew through radiation after bomb testing, what mutations might occur to the disease that the ticks or birds were carrying? Years ago defoliating was common along railway tracks, what if a tick or host was sprayed? I have been in contact with Mr. Donald Scott. It is interesting to speculate that a Brucella variant bacterium may be involved in the bunnies demise. Is man responsible for the declining hare population?

The 60's and 70's brought diminished rabbit populations compared to the 20's and 30's, I remember well-established trails and feeding areas. Forest fires were being controlled which diminished the rabbits food supply.

Today there are a few pockets of rabbits in the area but in some parts it is getting to be a novelty to see a rabbit. Where there used to be packed trails in the wintertime there is now only the odd rabbit track.

Authors note, April, 2006. I walk though hare habitat almost every day and this winter I did not see one single track.

There is no doubt that quality & quantity of food, predation and controlled forest fires have impacted the hare population but there are areas that the rabbit populations have not rebuilt, they are capable of having 3-4 litters in the spring. Trappers tell me we are at the top of the ten- year cycle.

I am hypothesizing that disease is a factor in the declining hare population and we share disease with nature more than commonly thought. I am interested in corresponding with persons in other areas where rabbit populations have declined from the historical highs of the 20's and 30's to the historical low of today. If we can show a problem then we can go on to finding the cause and then determine if it is being passed to humans. I feel we should look at the bunnies as canaries.

Authors note, April, 2006. It is interesting that I have never seen any research on the hare tick Haemaphysalis leporispalustris as being the cause of the declining hare population.

Authors note, February, 2007. Was just reading through my letters and notes from the 80's and 90's to try and find some clues to unravel the local hare mystery. I was reminded that I had killed a snowshoe hare with a stick and took 350 ticks off it. This makes sense as the hares were dying and the ticks were losing their hosts. Here is what I do not understand. When I was a kid in the 50's and early 60's I saw much larger die-offs, I do not remember hares with large numbers of ticks on them. I talked to oldtimers who could remember the 20's and 30's and I do not remember them mentioning great numbers of ticks. From this can we extrapolate that the ticks also died in a cyclic hare die-off? If most did not die would they not overwhelm the hares that survived the die-off? Hare ticks vectored by migratory birds and Lynx driving the 10 year cyclic hare die-offs makes sense.