Esquimalt will be the second Greater Victoria community to use birth control to manage the population of urban deer as part of a research project.
The presence of urban deer is a hot button issue on Vancouver Island, where they have been blamed for munching on landscaping, potentially spreading Lyme disease and posing a threat to vehicles.
Jason Fisher, adjunct professor at the University of Victoria's School of Environmental Studies, is leading the Esquimalt Deer Research project and says it will be identical to a project conducted in nearby Oak Bay in 2019.
While the results of the Oak Bay project are still being analyzed, Fisher can say, in broad strokes, that it was very successful in reducing the number of deer that are breeding. This season, those Oak Bay deer who were given contraceptives will be given booster shots.
Fisher says about 60 to 80 does in the Esquimalt area will now be given a birth control vaccine, then tagged and studied via a set of remote cameras to calculate the efficacy of the project.
"It should reduce the pregnancy rate by quite a bit and that's definitely what we're seeing in Oak Bay, where that fawning rate has dropped way down," said Fisher. "We expect 90 per cent of the does we give it to to not have calves."
Fisher says the project — one of the more unusual deer management programs in North America — came about after an unsuccessful cull in Oak Bay a few years ago.
"We can't just bring in hunters and have them wandering around Esquimalt or Oak Bay. We have to trap [the deer] and then euthanize them and it's devilishly difficult to get a deer into a trap ... so that proved to be very difficult," Fisher said.
He says the birth control method is more advantageous than a mass cull in which all the deer are wiped out at once.
"Once you remove the deer from an area, other deer from outside that area make exploratory movements," he said.
"Once they find an empty Oak Bay or an empty Esquimalt, they're going to move in and they're going to take those territories over and they're going to end up with a population refilling back again."
As long as the contraception is working, he says, the deer population should fall to a stable level.
"That's the research that we're doing, to make sure that is in fact what is happening and you don't get a flood of new individuals coming in."