Climate Change Ticks Off Moose - Then They Die

Photo by Don Bergeron, NH Fish and Game

Moose are disappearing from New Hampshire and other northern states.  They are being killed by winter ticks.  Minnesota’s moose mortality rate is so high that the state canceled its annual hunt in February.  In New Hampshire there have been years where almost none of the calves survived and only 25 percent of adults.

Winter cold used to keep the ticks under control.  Most winter tick eggs in New Hampshire would die over the winter, frozen to death.   But that hasn’t happened lately as winters are starting later and ending sooner.  

Winter ticks on the body of a Moose
Photo by Ron Moen, University of Minn/Duluth

A single female tick lays about 3,000 eggs. With warmer weather, ticks don’t die. Tens of millions of winter ticks will be hatching in September from eggs hidden in thick brush. They will wait there to hitch a ride on a moose and suck its blood until the end of May.  As the number of ticks explodes, moose have disappeared by the thousands. Many of those still alive are starving, with rib cages visible through ragged skin. 

As many as 150,000 blood-sucking insects can turn an 1,800-pound animal into a ‘ghost in the woods’, but not only by sucking out all of their blood.  The tick bites itch.

The moose lick and rub and scratch at the ticks until their fur falls off. They develop secondary infections.  They can actually freeze without their fur.  They develop anemia and starve. 

Who says climate change doesn't hurt anyone?

For more information, see this from the New Hampshire Wildlife Service.