From 2019 to 2022, an experimental trial program took place in Oak Bay where deer were being vaccinated with an immuno-contraceptive.

The aim was to test whether a non-lethal approach, like using birth control, could effectively control the urban deer population.

Now, for the first time, the numbers are in, according to Alina Fisher, a wildlife biologist with the Urban Wildlife Stewardship Society.

“We found that immuno-contraception is actually effective at reducing the deer populations. We saw an immediate response with the fawns decreasing the following year after it was initially applied,” Fisher said.

Watch below:

She said it took several years for any noticeable change to appear in the adult population.

“The reduction for the fawns was 65 per cent just in the following spring after immediate immuno-contraception. So it was very effective, very quickly,” Fisher said.

Despite the program’s success, deer are still noticeable across Oak Bay and neighbouring municipalities.

Oak Bay Mayor Kevin Murdoch says the deer are still regularly culled by vehicles.

“We don’t have any direct measure of exact deer population. We have some proxies, most notably dead deer that are picked up the street from our public works,” he said.

“That went down considerably after the contraception. It’s going back up now – of course we haven’t applied the immuno-contraception for a couple of years,” Murdoch said.

According to the district, vehicles struck and killed a high of 85 deer in 2021, and that’s dropped to 62 last year.

The mayor says he would like to see the program continue.

“Everything that we’ve seen so far appears that the contraception is effective, and it makes sense, the deer turnover is fairly high,” Murdoch said. “And if they stop fawning then there’s less deer being produced.”

The municipality is meeting with the province in November to determine whether the program should be reinstated and funded again.

Oak Bay received a grant of $42,000 in fall 2019 under the Provincial Urban Deer Cost-Share Program for the trial.

READ PREVIOUS: