Only intensive cull will reduce deer numbers

The only way in which contraception could work would be to prevent the movement of deer into the municipality.

Re: Deer a shared responsibility, (July 31).

I would like to add some comments, as a biologist, to the contrasting proposals to manage the blacktail deer population in Oak Bay.

The number of deer in any region will reach a rough equilibrium dependent on the balance between the amount of browse available and the level of predation.

In other words the more vegetation the greater the number of fawns born, and the more deer to consume the more the carnivores can reproduce. The two groups balance out, usually with a time lag.

In the case of Oak Bay two observations apply:

1. We have eliminated natural predators, and the automobile is an inefficient substitute.

2. Left alone the deer population will continue to expand towards the limit set by the food supply.

The trap-and-kill method of management employed briefly last winter could certainly reduce the deer population. But since deer evolved to compensate for predation the reduction will be temporary. More fawns will be born and adults will move in from adjacent regions.

Only an intensively applied cull over several years could effectively reduce deer numbers. Given the political opposition to deer culls this is not practical.

An alternative to killing animals that has been suggested is to treat does with a contraceptive.

This will not reduce the number of deer but will result in fewer fawns.

The treated does will eventually die of old age and their place and that of their never-born offspring will be taken by the migration of deer into Oak Bay. The rule is: if there is food they will come.

The use of a contraceptive will not reduce the deer population in Oak Bay and thus seems pointless.

The only way in which contraception could work would be to prevent the movement of deer into the municipality.

Given the experience of the Australians in analogous circumstances with a rabbit-proof fence (but rabbits cannot jump an 8ft fence) I do not give much credence to isolating Oak Bay from outside deer which would be required.

This is merely the opinion of a scientist. Others are entitled to their own opinions.

Joe Harvey

Oak Bay

 

Just Posted

Black Press file photo
RCMP seek suspect in Vancouver Island-wide crime spree

Crimes stretched from Deep Bay to Qualicum, Ladysmith, Chemainus and Youbou

Karl and Stephanie Ann Johanson were thrilled to spot a pair of Sandhill Cranes in the Panama Flats this month, an unusual appearance for such birds. (Photo by Stephanie Ann Johanson)
WATCH: Sandhill cranes an unusual, joyful sight in Saanich parkland

The birds don’t often touch down in the south of the Island

Jesse Roper tackles weeds in his garden to kick off the 2021 season of What’s In My Garden Man? (YouTube/Whats In My Garden)
VIDEO: Metchosin singer-songwriter Jesse Roper invites gardeners into his plot

What’s In My Garden, Man? kicks off with the poop on compost

(Victoria Cool Aid Society/Facebook)
Victoria food drive aims to feed those also struggling with housing

Quadra Village furniture store hosting drive-thru event Saturday from 10 a.m. to 2 p.m.

Victoria police are asking for witnesses who might have information about this tricycle that was stolen in downtown Victoria on Thursday. (Photo courtesy of VicPD)
Police seek witnesses after downtown Victoria company’s tricycle stolen

The three-wheeler was taken from the 2100-block of Store Street on Thursday

A small pod of Pacific white-sided dolphins pass by close to shore in Campbell River June 16, 2021. Still capture from video courtesy of Kimberly Hart
VIDEO: Dolphin sunset captured from Vancouver Island shore

Spectacular setting for view of travelling pod of Pacific white-sided dolphins

Police are asking for public assistance in locating Anthony Graham who has been charged with the murders of Kamloops brothers Carlo and Erick Fryer. (RCMP photo)
2 charged, suspect at large in killings of B.C. brothers linked to gang activity: RCMP

Kamloops brothers Erick and Carlo Fryer were found deceased in May on a remote Okanagan road

Albert Health Minister Tyler Shandro and Alberta Premier Jason Kenney unveil an opening sign after speaking about the Open for Summer Plan and next steps in the COVID-19 vaccine rollout, in Edmonton, Friday, June 18, 2021. THE CANADIAN PRESS/Jason Franson
Alberta 1st province in Canada to lift all COVID-19 public health restrictions

70.2% of eligible citizens 12 and older in the province have received a dose of the vaccine

Fraser Health registered nurse Ramn Manan draws a dose of the Pfizer COVID-19 vaccine into a syringe at a walk-up vaccination clinic at Bear Creek Park, in Surrey, B.C., on Monday, May 17, 2021. THE CANADIAN PRESS/Darryl Dyck
‘Honour our fathers’ with COVID-19 vaccine protection, B.C. urges

109 new cases Friday, 75 per cent of 12 and up immunized

Freighters have becomd abundant in the Trincomali Channel on the east side of Thetis Island.
Nanaimo ponders taking on waste from nearby anchored freighters

Vancouver-based Tymac petitioning the Regional District of Nanaimo to accept waste at its landfill

(Paul Henderson/ Chilliwack Progress)
Trutch Avenue in Chilliwack to be renamed to remove racist taint

New name to have Indigenous significance as Chilliwack takes new step toward reconciliation

Canadian Prime Minister Justin Trudeau is seen during a joint news conference following the EU-Canada Summit, in Brussels, Belgium, Tuesday June 15, 2021. Trudeau says Canada is on track now to have 68 million doses delivered by the end of July, which is more than enough to fully vaccinate all 33.2 million Canadians over the age of 12. THE CANADIAN PRESS/Adrian Wyld
Vaccine deliveries enough to fully vaccinate all eligible Canadians by end of July

Three in four eligible Canadians now have their first dose, nearly one in five fully vaccinated.

Chief Public Health Officer Theresa Tam listens to a question during a news conference, in Ottawa, Tuesday, Jan. 12, 2021. The number of confirmed COVID-19 cases attributed to the highly contagious Delta variant grew in Canada this week. THE CANADIAN PRESS/Adrian Wyld
Canada’s public health agency reports spike in confirmed cases of Delta variant

More than 2,000 cases of the variant confirmed across all 10 provinces and in one territory

Most Read