Mouse infestation could last all year

  • Jun. 8, 2011 6:00 p.m.

Islanders, especially in Port Clements and Tlell, are coming across more mice than usual, and it’s all thanks to last year’s big cone crop, says naturalist Berry Wijdeven. Mr. Wijdeven, a species at risk coordinator for the Ministry of the Environment, said he first heard people complaining about mice in April, and the number of complaints increased in May. “There’s a lady in Tlell who had five in her van, chewing through her wiring,” he said. “I was at a potluck and everybody had stories about mice in their walls and on their floors.” Mr. Wijdeven, who has been trapping about two mice a day in his own home, was not at all distressed about the infestation, because it firmed up a connection he had long thought existed between big cone years and rodent population increases. Basically, last year was a “masting” year, which is biologists’ term for a season with lots of pollen, lots of cones, and lots of other plant reproductive activity. Mr. Wijdeven photographed several different kinds of trees heavy with cones last year, including spruce, red cedar and yellow cedar. This led to observed increases in the number of crossbills (a type of songbird) and squirrels by last summer, and to this spring’s mouse invasion. We will probably keep seeing more mice than usual all year, Mr. Wijdeven said, as there are still lots of cones on the ground and in the trees for them to eat. The mice here are deer mice and they are native to Haida Gwaii, although rats and squirrels are introduced. What’s next in this cycle? “Hopefully, there will be more goshawks and owls,” Mr. Wijdeven said, as well as marten and other predators that eat mice and squirrels.