Moose Die-Off Concerns Scientists

http://www.nytimes.com/2013/10/15/science/earth/something-is-killing-off-the-moose.html?_r=0&adxnnl=1&ref=science&adxnnlx=1381961407-o+tdzvNc2AEqWmvuiLt97w

Moose Die-Off Concerns Scientists

Twenty years ago, Minnesota had two geographically separate moose populations. One of them has virtually disappeared since the 1990s, declining to fewer than 100 from 4,000. The other population, in northeastern Minnesota, is dropping 25 percent a year and is now fewer than 3,000, down from 8,000. In Montana, moose hunting permits fell to 362 last year, from 769 in 1995. Winters have grown substantially shorter across much of the moose’s range. In New Hampshire, a longer fall with less snow has greatly increased the number of winter ticks, a devastating parasite. Another theory is heat stress. Moose are made for cold weather, and when the temperature rises above 23 degrees Fahrenheit in winter, as has happened more often in recent years, they expend extra energy to stay cool. That can lead to exhaustion and death.