Moose Die-Off Baffles Scientists: What May Be Causing The Massive Drop In North American Populations?
Moose populations are plummeting across North America, and scientists are not quite sure why, the New York Times reports. With the moose die-off occurring in places as far away from one another as British Columbia and New Hampshire, scientists speculate that various effects of climate change are the most likely culprit.
The moose die-off is particularly severe in places like Minnesota. The state has moose populations in two different area of the state. One population has dropped from 4,000 moose to fewer than 100 since the 1990s; the other has fallen from 8,000 to under 3,000 -- with a drop of 35 percent from last year.
Like Us on Facebook
What might be causing the moose die-off? Take your pick. There are many possible culprits, all revolving around climate change.
In Minnesota, moose may be inadvertently feeding on snails infected with brainworm, which causes disorientation, neurological damage and eventually death. The liver fluke, a flatworm, is considered by one study to be the greatest single source of moose deaths in northwestern Minnesota. Both brainworm and liver flukes thrive in moist environments.
In New Hampshire, shorter winters with less snow and longer falls have led to an increase in winter ticks. Up to 100,000 of these nasty suckers can attach to a single moose, one New Hampshire Fish and Game biologist told the New York Times. Warmer New Hampshire winters mean that winter ticks aren't dying off with the cold, and with a single winter tick capable of laying 3,000 eggs, the tick population is robust.
Heat stress might be playing a role too. Warm winters are bad for moose, with their thick hides and dense hair. When the temperature rises above 23 degrees, moose have to expend energy to cool off, which can result in exhaustion and death.
Compounding the problem of diagnosing the cause of the moose die-off is the fact that it's hard to study moose deaths. They don't travel in herds, so are difficult to track. Their body fat is very high, so they decompose extremely quickly. Just one day after death, a moose necropsy is worthless.
In Minnesota, the Department of Natural Resources is engaged in one of the cooler things to ever take place in the generally staid world of moose necropsy. Wildlife managers there are spending $1.2 million to outfit 150 moose with GPS technology that sends out a text message and coordinates if a moose dies. Then a team descends on the site of the dead moose, sometimes via helicopter.
"As soon as it stops moving for six hours, we'll be alerted the animal has died," said Ericka Butler at the Department of Natural Resources. "We have crews and trained field staff who are trained with moose moralities and within 24 hours get there and get the whole carcass out intact. If we can't do that we'll do a very thorough field necropsy."
Below is a video of a moose walking around a Canadian supermarket.
© 2012 iScience Times All rights reserved. Do not reproduce without permission.