Of Moose and Men… and Ticks, Nematodes, and Climate

by Barry Kent MacKay in Blog, Coexisting with Wildlife

Photo by U.S. Fish and Wildlife Service (https://flic.kr/p/bsphpr) via: freeforcommercialuse.org.

When I mention my concerns about the cruelty climate change is imposing on animals, I suspect that most folks think of starving polar bears or koalas consumed by the unprecedented fury of contemporary brush fires in Australia.

Of course, those are among a massively growing collection of perils being directly visited upon the shrinking populations of the world’s wildlife. But, there are indirect dangers. In New Hampshire and Maine, it’s been estimated that over a three year period some 70 percent of moose calves failed to survive. It’s already known that, throughout much of their forested range in the northern U.S. and across much of Canada, there have been severe moose declines. A recent study in New Brunswick verified that one profound problem is the growing numbers of ticks.

These small, bloodsucking arachnids have been around since the Cretaceous (146 to 66 million years ago). From the time of the dinosaurs until the present they’ve been sucking blood. One New Brunswick moose was the unwitting host to about 80,000 ticks. Not only can ticks transmit disease, but in such high numbers they can remove too much blood, weakening the host animal’s ability to survive.

Experts studying climate have determined that winters are milder with less snow, on average, than previously, and biologists know this enhances winter survival of ticks, as well as their northward expansion. And then, there is brainworm, Parelaphostrongylus tenuis, a nematode parasite that infects white-tailed deer. The white-tails have co-evolved with the neurotropic worm and tend to survive, but not so the moose. Warmer weather and forestry practices have encouraged northward movement of white-tails into traditional moose habitat, with disastrous results for the moose who may sicken and die from the effects of the brainworm. That is in addition to the swarms of mosquitoes and blackflies that, each summer, can drive a moose to distraction. But, mosquitoes, blackflies, and moose have always co-existed. Brainworms, a burgeoning populations of ticks, and habitat loss are new impositions and, in response, moose numbers have dramatically declined in many regions.

Whether or not the rate of global climate change can be slowed or halted will be known at some distant future time. Meanwhile, what can conservationists do to help moose survival?

Stop killing them? That seems to be the first, and most simple, solution to the problem, but no, sport and trophy hunters are too fond of killing moose to do that. They prefer to expand the killing to natural moose predators. Bears have been known to eat moose calves, so kill bears. Wolves too. Kill, kill, kill!. It’s what we do, and we see endless schemes to try to reduce the harm of such killing by restricting number of hunters through the use of lotteries to choose who gets to do the killing, and questioning if calves should be hunted or protected. (Hint: they should be protected, along with adults.)

Change happens, and animals adapt through the evolutionary process, but sport and trophy hunting interferes with adaptation by removing not those animals most vulnerable to change, but those most sought by the hunter – often those animals that are the largest and healthiest in a population.

Hunters like to claim they “take” the animals “surplus” to the number needed to perpetuate the species. but no healthy animal is “surplus” in a declining population. Bears and wolves co-evolved with moose over tens of thousands of years. They are not new to each other. What is new is high-powered weaponry. Mind you, when humans first arrived in North America as long as 15,000 years ago, they triggered a wave of extinctions of both far more large predators than are here today, and more kinds of deer and other herbivorous species, with weapons we would think are absurdly primitive.

We humans are by far the world’s most deadly destroyer of species and our activities directly and indirectly contribute to the carnage. Moose can survive parasites and predators, but they probably cannot, I fear, survive us.

Keep Wildlife in the Wild,
Barry

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