It’s official: The National Oceanic and Atmospheric Association has declared this July the hottest one on record, following a record-setting June.
It is a well know fact that our warming winters have contributed to a significant decline in moose numbers across New Hampshire over the last decade and a half. The state’s moose population has declined from about 7,500 to closer to 3,500 today.
Most folks attribute much of this decline to our shorter winters causing an uptick in the winter tick numbers that are literally killing off our moose, especially the calves.
According to Fish and Game Department moose biologist Kris Rines, it is the lack of snow in April, when the female ticks drop off to lay their eggs, and a late winter with no snow in November when the baby ticks are seeking moose, that are the root of much of the problem.
No snow when females lay their eggs in the spring means lots of baby ticks. No snow late fall going into winter gives the baby ticks much more time to get on a moose.
Last fall there was no snow on the ground up north until late December, giving the baby ticks an extra month and a half to find a moose.
As a result, according to the ongoing UNH/Fish and Game moose study, there was an average of 42,000 ticks on each moose.
Moose calves cannot support those numbers and 81 percent of the moose calves died last winter, along with nearly 25 percent of adult cows.
But winter moose mortality really only tells half of the story as to why our moose numbers are down to half of what they were 15 years ago.
Yes, our shorter winters are a big factor, but so too are our ever-warming summers.
The fact is moose stop feeding when temperatures reach the high 70s. And do moose ever feed – some 40 pounds of browse a day. Let’s put it this way: If you filled your bathtub with leaves and twigs, a moose would eat it all in a day, or make that a night.
And this summer’s high temperatures have no doubt further impacted our dwindling moose herd.
Just the other night while watching the 10 o’clock news, I could see that almost statewide temperatures were still in the 80s. At these temperatures, moose cows cease to feed.
As it already is, because of our warmer summers, adult cow moose body weights are down, causing a significant reduction in moose calve births.
The percentage of cows giving birth to twin calves was down to only 11 percent when the 2002-2005 moose study was conducted by Fish and Game. In the last three summers of the current study, no twinning has taken place.
And the calving rate has declined from 75 percent of adult producing calves in 2002 to only 54 percent last year and 60 percent this year. So this summer’s heat wave lasting weeks, with temperatures at 80 degrees at 10 at night, will only further reduce cow weights and future reproduction.
We really have a double whammy on our moose population.
Fewer moose calves are being produced by our underweight cows and a much higher death rate is killing off the few calves that are born.
In fact, the most recent population model that I saw presented by one of the moose study scientists predicts that given the current winter mortality factors, and the loss of reproduction due to warmer summers, our New Hampshire moose population will essentially be gone by 2045. That’s right, in less than 20 years moose will be gone from this state, save for a remnant population.
How sad of a legacy we are leaving our grandchildren.
We all must do our part to address climate change. Through the Regional Greenhouse Gas Initiative and the EPA’s Clean Power Plan, we can cut carbon and make a difference.
Each of us can in some small way help save our moose for future generations.
Please do your part.
(Eric Orff of Epsom is a wildlife biologist.)