Vermont’s moose population is in trouble and scientists fear climate change is to blame.
Despite a significant reduction in moose hunting permits issued by the state, the population continues to decline, or stay stagnant at best. Mortality rates are high and birth rates are low. Scientists are pointing to climate change as the cause. They say warmer, wetter weather allows two moose parasites to thrive: winter ticks and brainworms.
The state Department of Fish and Wildlife is in the midst of a multi-year study to learn more about the extent of the danger.
Around 50 people came out to the NorthWoods Stewardship Center in Island Pond on a blustery Wednesday evening to learn about the condition of Vermont’s moose herd. Moose chili and cornbread were served up as the crowd settled in to the center’s main cabin, warmed by a woodstove and perfumed with a balsam Christmas tree.
While the setting was cozy, the news about the moose population was alarming.
Cedric Alexander is the department’s Moose Project Leader. He says nearly half of the moose tracked in the first year of the study died. And one of the main culprits is winter ticks . A single moose can have tens of thousands of them.
Alexander says the next two years of data will give the state a better picture of the problem.
“We know that tick populations vary based on weather conditions and so the 40 percent mortality that we found last year," Alexander says, "is that the highest that we’ll have? Or is that going to be the lowest? Or is it going to stay the same? That’s all going to be very critical information to learn.”
Alexander says the number of moose affected by brainworm also appears to be on the rise. Brainworm is common in whitetail deer, but does not harm that species. The worm affects the central nervous system of a moose, causing it to act strangely and eventually die or, often, have to be put down.
“The incidence of brain worm just seems to be – I don’t want to use the word skyrocketing – but it doubled, basically, in the southern part of the state," Alexander says. "It seems like there’s always another moose that’s got brainworm that’s hanging out in some backyard or near some highway, and it’s something the wardens have to try to take care of.”
Summer rain showers, bring... brainworms
Alexander says some studies show the larval stage of the worm lives in snails, which are more abundant in wetter summers like the ones Vermont has experienced lately. So, more summer rain might explain the rise in number of moose affected by brainworm.
It seems clear that warmer winters and wetter summers are affecting the state’s moose herd. But the study hopes to flesh out just how those factors affect the the animals.
To do that, the state is outfitting moose calves and cows with tracking collars. The department plans to track the moose that survive for all three years of the study. And 30 more calves will be collared in each of the second and third years.
Jake DeBow started working on the study as a Vermont Fish and Wildlife employee. And he will stay on for the duration of the study, but as a graduate student at the University of Vermont.
After the Fish and Wildlife presentation, meeting-goers broke into small groups. The group at DeBow's table got to hear specifics about how the tracking collar works.
“It has a GPS and a VHF beacon. So we get two GPS points sent to a program that we can hook up to with our computer," says DeBow. "And it’s also always going to be a constant VHF beacon that we can pick up on with a receiver. So we get our GPS point in the morning. We get a general idea of where they are. And then we go to walk in on them and we use our receiver and the VHF signal to hone in and actually find the animal.”
At the end of the meeting, each of the break-out groups shared their questions and concerns with Fish & Wildlife officials.
And scientist Cedric Alexander says he’s looking forward to the same give-and-take in other communities around Vermont.