BANGOR, Maine — The state’s top moose biologist said on Monday that data gathered through a moose research project provided the tipping point when the Department of Inland Fisheries and Wildlife reduced hunting permits by nearly 25 percent last week.
“The bottom line with what happened this year is that we have our [moose] survival project up and running with GPS-collared animals out there,” DIF&W wildlife biologist Lee Kantar said. “We’re trying to quantify survival rates.”
And as a particularly harsh winter season stretched on, the survival rates biologists were tracking among their subject animals — 30 adult females and 30 calves — kept dropping.
By the end of the winter, nine of the 30 adults (30 percent) had died. The less-adaptable calves, with little extra body weight entering winter, fared even worse, with 21 of 30 (70 percent) dying.
Kantar said the DIF&W has not had access to that kind of data in the past, and said the last time the department could study radio-collared moose was back in the 1980s.
Armed with that data, the department reduced the number of moose hunting permits from the 2013 level of 4,110 to 3,095. That 24.7 percent reduction from one year to the next was unprecedented for the state’s modern moose hunt, which began as an experimental season in 1980, was discontinued for a year, and has taken place annually since 1982.
In fact, this year will mark just the fourth time since 1982 that the number of permits has been reduced from one year to the next.
In 2002, the state allotted 36 fewer permits than it did a year earlier. In 2003, 371 fewer permits, a 12.5 percent reduction, were offered. And in 2006, the DIF&W dropped the permit level from 2,921 to 2,825, a reduction of 96.
This year’s permit reduction brings the total to a level roughly equivalent to the number issued in 2010 (3,140).
While hunter success rates peaked during the 1980s and early 1990s, when 85 to 95 percent of hunters filled their tags each year, present-day hunters still have a great chance of heading home with a moose if their name is drawn during the annual permit lottery.
In 2013, 72.4 percent of hunters filled their tags.
Kantar receives an email alert every time a moose in the study group dies, and he scrambles a team to the woods to find the moose and perform a necropsy.
Lab results from those necropsies have not been completed, but biologists felt confident that an especially heavy load of winter ticks on the dead moose likely played a role.
Kantar said using the data to make management decisions mirrors the technique that Maine biologists have been using for years.
“It’s the same dynamic that we’ve used for decades with deer,” Kantar said. “If you incur heavy winter losses, you compensate when you adjust your permit levels.”
The state will not reduce the number of bull moose permits that will be available for this year’s hunts. The reduction will come in the form of fewer hunters being allowed to hunt cow moose.
In a press release announcing the permit reductions, Kantar said that even though winter ticks were heavy this year, decreasing the number of permits will allow the department to meet population goals.
Maine has been studying the effect of winter ticks for years. Biologists sample the tick load on hunter-killed moose at tagging stations each fall, and some of the results have been stunning.
Kantar said that last year it wasn’t uncommon to find 60 larval ticks along a 16-inch series of transect lines where biologists look for the parasites. Multiply that over the entire back of a moose, and the tick load can compromise the health of a moose, he said.
“The calculations have been made that the ticks on the back of a moose take enough blood volume to create either a chronic state of anemia or an acute state of anemia,” Kantar said. “It’s lost so much blood that it can’t replace it. It puts a hurt on them.”
Calves, with little or no protective fat entering the winter, are often the first to succumb to illness or ailments, Kantar said.
“When a calf is in the late summer going into fall, it’s still growing and it doesn’t have any time to deposit fat on its body. So going into winter you’ve got a smallish animal that’s got no fat,” Kantar said. “You get a winter when it’s got a ton of winter ticks on it, and now it’s plowing through heavy snow, at a time when nutritionally, it’s the poorest time of year for moose. It’s got all this against it. That’s a tough situation for a moose calf in its first winter to get through.”
Kantar said that the data provided over the recently completed winter helped biologists respond quickly.
“We should be encouraged by the fact that we have this kind of resolution of data and we’re able to make this kind of informed decision as opposed to the alternative,” Kantar said. “In general, the state needs to be conservative as far as moose permits are concerned. You can’t take back a bullet.”