Moose in Trouble as Climate Boosts Pests
Moose — the majestic loners of northern woods — are dwindling sharply.
A rise in moose die-offs has been reported in Minnesota, Montana, Wyoming and other parts of the Rocky Mountains, according to recent reports in the Bangor Daily News and the New York Times. In Minnesota, moose populations have dropped so steeply that the state canceled its annual hunt in February.
Moose populations in New Hampshire also appear to be in trouble. Only populations in Maine, where temperatures have dropped but still remain relatively cold, seem stable, according to the reports.
One big factor appears to be ticks — and a climate that is warming up to their liking.
Death by ticks is a gradual, miserable end. Up to 150,000 of the insects can infect a single moose. The ticks weaken the animals, whose males reach about 7 feet in height and up to 1,800 pounds in weight. Covered in blood-sucking ticks, the moose scratch so much, their fur rubs off. They develop anemia and become emaciated.
The ticks infest the moose in early spring. Normally the ticks and their eggs die as winter sets in, but warmer winters have allowed the ticks to survive — and multiply.
“It’s pretty depressing,” Kristine Rines, a wildlife biologist and moose project leader for the state’s Fish and Game Department told the Bangor Daily News. “It’s a pretty tough way to go. There’s no question that climate plays a huge part in this. If we had winters that lasted as long as they used to, we might not be having this conversation.”
Other pests — encouraged by warming — are also taking their toll. In Minnesota, brain worms and liver flukes are infecting moose. Both of these pests spend part of their life cycles in snails, which do better in warm, moist environments.
Finally, the warming climate, itself, could be a factor since moose are designed for the cold. When temperatures rise above 23 degrees Fahrenheit in winter, the animals are forced to expend extra energy to keep cool. That leaves them exhausted and vulnerable.