Moose populations across North America are plunging at an alarming rate—and scientists can't figure out why. The die-off has hit regions from British Columbia to New Hampshire, and one of Minnesota's two moose populations has declined from 4,000 animals to fewer than 100 since the 1990s, the New York Times finds. Moose hunting in the state has been suspended while the decline is investigated, although experts believe the drop in moose numbers has a lot more to do with climate change than with hunting.
In some areas, shorter winters have caused an explosion in the numbers of winter ticks, up to 100,000 of which can gather on a single moose, sucking so much blood the animal becomes anemic—and causing it to scratch off its fur. Heat stress and snail-borne diseases are also believed to be a factor in many moose deaths. Moose are solitary animals so their deaths are hard to track, but researchers in Minnesota aim to get some answers this fall with a monitoring system that sends out an alert as soon as a moose dies. (Read more moose stories.)