mooseMoose populations are suddenly in steep decline across North America, including in New Hampshire, where moose-watching tourism is a $115-million-a-year business.

According to an article in the New York Times, moose populations from Montana and British Columbia to the Northeast are experiencing a frightening die-off. And no one seems to know why.

Theories abound. In New Hampshire, biologists think it might be the huge increase in the number of winter ticks, which drive moose crazy. Biologists say 100,000 ticks can be found on a single moose.

But whether the theory is ticks or moose overheating in warm temperatures, they all seem to point the finger at one culprit: climate change. New York Times editorial in the same issue says the collapse in moose numbers is typical of the kind of shifts that a warming climate is causing, tipping the balance in ways that favor some species and do grievous harm to others.

Read more about the declining moose population.