|Tennessee Hunters Alliance
|Moose Die-Off Alarms Scientists
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|Author:||TnTodd [ Tue Oct 15, 2013 6:02 pm ]|
|Post subject:||Moose Die-Off Alarms Scientists|
Moose Die-Off Alarms Scientists
CHOTEAU, Mont. — Across North America — in places as far-flung as Montana and British Columbia, New Hampshire and Minnesota — moose populations are in steep decline. And no one is sure why.
The other population, in northeastern Minnesota, is dropping 25 percent a year and is now fewer than 3,000, down from 8,000. (The moose mortality rate used to be 8 percent to 12 percent a year.) As a result, wildlife officials have suspended all moose hunting.
Here in Montana, moose hunting permits fell to 362 last year, from 769 in 1995.
“Something’s changed,” said Nicholas DeCesare, a biologist with the Montana Department of Fish, Wildlife and Parks who is counting moose in this part of the state — one of numerous efforts across the continent to measure and explain the decline. “There’s fewer moose out there, and hunters are working harder to find them.”
What exactly has changed remains a mystery. Several factors are clearly at work. But a common thread in most hypotheses is climate change.
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. “You can get 100,000 ticks on a moose,” said Kristine Rines, a biologist with the state’s Fish and Game Department.
In Minnesota, the leading culprits are brain worms and liver flukes. Both spend part of their life cycles in snails, which thrive in moist environments.
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.
In the Cariboo Mountains of British Columbia, a recent study pinned the decline of moose on the widespread killing of forest by an epidemic of pine bark beetles, which seem to thrive in warmer weather. The loss of trees left the moose exposed to human and animal predators.
In Smithers, British Columbia, in April, a moose — starving and severely infested with ticks — wandered into the flower section of a Safeway market. It was euthanized.
Video by Scenes-Sections
Moose dies after B.C. Safeway stroll.
Unregulated hunting may also play a role in moose mortality. So may wolves in Minnesota and the West.
Scientists and officials say other factors could still emerge. Because most moose die in the fall, the next few months may provide insight.
“It’s complicated because there’s so many pieces of this puzzle that could be impacted by climate change,” said Erika Butler, until recently the wildlife veterinarian at the Minnesota Department of Natural Resources.
The stakes go beyond the moose themselves. The animals are ecosystem engineers; when they browse shrubs, for example, they create habitat for some nesting birds.
And moose contribute to the economy. In New Hampshire, for instance, moose-watching tourism is a $115-million-a-year business, according to Ms. Rines. Hunting permits also generate revenue.
Moose deaths are hard to study, scientists say. The moose is a member of the deer family, but unlike deer it is a solitary animal that does not run in herds, so it can be hard to track. Moreover, moose have such high levels of body fat that they decompose rapidly; after 24 hours, a necropsy has little value.
In January, Minnesota started an unusual $1.2 million study using advanced monitoring technology to find moose as soon as they die. Live animals are captured and fitted with collars that give their location every 15 minutes, and they are given feed containing a tiny transmitter that remains in the body and monitors heart rate and temperature. Then the moose are released back into the wild.
“If the heart stops beating, it sends a text message to our phone that says, ‘I’m dead at x and y coordinates,’ ” said Dr. Butler, who leads the study. The messages are monitored around the clock; when a moose dies, a team on call rushes to the scene by car or helicopter.
The winter tick problem in New Hampshire is particularly vexing. The animals lose so much blood they can become anemic. Worse, the ticks drive the moose crazy; they constantly scratch, tearing off large patches of hair.
Some moose lose so much hair they look pale, even spectral; some people call them “ghost moose.” When it rains in the spring, the moose, deprived of their warm coats, then become hypothermic.
Winter ticks hatch in the fall and begin to climb aboard their host. They are dormant until January or February, when they start to feed, molt into adults and then drop off.
Moose spend a lot of time feeding in lakes, but wading in water doesn’t drown the ticks, which form an air bubble that allows them to survive immersion in water.
New Hampshire’s winter tick problem is a relatively recent phenomenon. But then, so are moose. The animals were hunted out of existence during Colonial times; they returned to the state only in the 1970s.
While deer have evolved to an ecological balance with ticks, moose have not.
Deer are grooming animals, so they are able to keep tick numbers fairly low. By contrast, said Ms. Rines, the biologist, “moose didn’t evolve with ticks, and they don’t groom them off.” That has led to swarms of ticks.
The solution to the tick problem might be, paradoxically, more moose hunting. “It’s up to the public,” she said. “We could kill more if we want healthy moose.”
http://www.nytimes.com/2013/10/15/scien ... moose.html
|Author:||TnTodd [ Tue Oct 15, 2013 6:04 pm ]|
|Post subject:||Re: Moose Die-Off Alarms Scientists|
Moose die-off: 100,000 ticks on just one moose, is Lyme disease culprit?
October 15, 2013
Moose die-off, this is a term that is not going away anytime soon as moose are disappearing at an alarming rate across North America. This moose-die off is seen in several northern states were ticks are prevalent and according to the N.Y. Times on Oct. 14, moose have been found with over 100,000 ticks on them.
According to the Northern Wild website, moose are testing positive for Lyme disease.While climate change is considered a variable in the moose-die off, it is also a factor in the amount of ticks you will find during any given year. Ticks thrive when the weather is warmer.
The winter tick is one of several types of ticks found on animals in the wild, and according to the website, Moose in Minnesota, this state is one of the states seeing the moose die-off, the moose population are visibly suffering from the ticks.
This is seen with moose that are missing massive spots of fur, as they have tried to remove the ticks from their bodies by rubbing up against trees. While a few ticks sucking the blood of a moose doesn’t lead to much blood loss, but a hundred thousand ticks sucking blood can leave the moose with substantial blood loss.
The winter tick, found on moose, take their final blood meal in the spring, a time when the moose are at their weakest from a winter of very little food. According to Lymedisease.org, a moose calf can lose their entire blood supply from ticks, killing them.
Lymedisease.org reports researchers blaming climate change for the population explosion in ticks. This is because ticks live longer when it is warmer and “reproduce in greater numbers if there’s less snow on the ground by spring.”
The battle between moose and tick is seen on the moose called “ghost moose,” where large patches of white skin are seen because the ticks have ravished their bodies to the point that they are constantly rubbing up against trees trying to rid themselves of the parasite.
The winter tick is the species causing the most problem for moose in North America and this could very well be the origin of the moose die-off. In the fall, winter tick larva climb vegetation until they reach a height, which is about chest level of the moose. The larva stay there waiting for a host to brush by and carry them away. Up to 300,000 larva can jump on one moose.
While there are other hosts in the great outdoors, such as deer, moose seem to be a magnet for the winter tick, according to the Moose in Minnesota website.
Anyone who owns a dog in the northern part of the U.S. knows the danger of ticks to their domestic animals. Ticks are causing three strains of Lyme disease in dogs today and it is taking massive amounts of potent antibiotics to rid the dogs of the Lyme strains.
According to the Northern Wilds website, moose are testing positive for Lyme disease, but the symptoms associated with Lyme are not seen in the moose. The uncertainty around the moose die-off causes indicates the need for more research and a grant of $1 million plus has been allocated for the state of Minnesota to equip moose with monitoring and GPA equipment.
This equipment will give the location of a tagged moose every 15 minutes. When the monitoring equipment indicates that the moose’s heart has stopped beating, wildlife staff will retrieve the body to study what the moose died from. Because moose are loners they are not easy to find in the wild and usual when a moose carcass is retrieved, it has been dead for a while.
With this new technology, researchers will be able to study the moose right after it meets its demise, hopefully this will give some indication in the cause of the moose die-off.
http://www.examiner.com/article/moose-d ... se-culprit
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