Regional drought blamed for Wyoming moose decline

Nov 10, 2011

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Big game hunting is big business here in Wyoming, and almost nothing is off limits to hunters, ranging from bison to mountain lions to moose. But a dramatic drop in the state’s moose population is hurting people who make a living from big game. Wyoming Public Radio’s Tristan Ahtone reports the reasons for the decline are complicated.

TRISTAN AHTONE: When you walk into Fritz Meyer's home the first thing you'll notice are the animals: bears, elk, big horn sheep and just about any other beast worth mounting on a wall. Meyer is a wildlife outfitter, which means for a fee, he'll take you out into the backcountry to bag any animal you have a license for. One of his major sources of income is moose hunts - or rather, he says it used to be.

FRITZ MEYER: I'd normally take, oh, at least five moose hunters probably. This year I've got one, and lucky to get that one.

AHTONE: And at $5,000 dollars per guided moose hunt, his business has suffered. In northwest Wyoming where Meyer lives and operates there’s been a drop for other outfitters too.

MEYER: My feeling here that a lot of it is predators, it’s really taken a big decline since the wolves have moved in here. But, you know, it’s like a big pie and it all fits together.

MATT KAUFFMAN: We sat down with Game and Fish and started looking statewide and realizing that most of the herds in the state were showing some evidence of decline.

AHTONE: That’s Matt Kaufman, a zoologist at the University of Wyoming. Over the last decade Kaufman says the moose population has dropped by nearly 30-percent, which means the number of hunting licenses has also dropped to about half. With over 300 outfitters in the state specializing in moose hunts, you can imagine the impact on the hunting industry.

KAUFFMAN: There are two things that Wyoming moose are experiencing that are truly regional, and that’s the expansion of wolves and grizzlies and this ten year drought that we’ve been in.

AHTONE: Kaufman says it’s impossible to say what portion of moose losses comes from predators, but he says there are some measurable aspects to drought:

KAUFFMAN: Moose on their summer ranges use a lot of wet habitats - bog and lakes - and some of those have been drying up over the ten years of drought.

AHTONE: Another aspect of that drying effect is that food for moose is produced quickly, but shortly… meaning that in the summer when moose put on weight for the winter, they have less to eat and have less fat for the cold months, impacting moose survival, birth rates and leaving the animals more susceptible to things like disease…


AHTONE: Today, Game and Fish Wildlife Biologist John Henningsen is using an electric saw on a moose head to check for a parasite called elaeophora.

JOHN HENNINGSEN:  This was a bull that they did keep the antlers from, so they’ve skull capped it. So the hunter is done with the head now, now I get to make use of it.

AHTONE: Elaeophora can cause blindness and death in moose, and Henningsen says the leading theory for why the parasite is spreading, is horse flies.

HENNINGSEN: Whether it’s just by the number of horse flies that are alive or the length of the season that they're operating in. When we have hotter, drier conditions, horse flies actually do better.

AHTONE: And those increases in temperature have led scientists to look for reasons why. Bryan Shuman teaches geology and geophysics at the University of Wyoming. He says over the last 30 years, average temperatures in the state have risen up to three degrees and attributes it to this: greenhouse gasses caused by the burning of fossil fuels and the clearing of forests.

BRYAN SHUMAN: I tried to put everything on the table look at all the possible things, solar variability, ocean variability, natural cycles in the earths system, and what it came down to was that there was no way I could explain the most recent episode of more frequent, warm years, without including greenhouses gasses.

AHTONE: According to Shuman, when the average temperature in Wyoming goes up a degree, the average rainfall decreases by 3 inches.  Shuman says there is evidence that some warming comes from natural causes, but that the general trend towards more frequent, warm years can only be explained by a global rise in carbon output caused by human activity.

SHUMAN: People certainly have this question: “is this a real thing?” well, I kind of feel like a doctor back in the 50’s and 60’s who realized that tobacco was causing cancer, and I think it’s going to take a while before the political winds come around to realizing the science is there.

AHTONE: And that science is showing adverse effects on food and habitat for moose, and of course hunting outfitters like Fritz Meyer.

MEYER: It’s the sportsmen and everybody that’s takin’ the brunt of the wrap on this because there’s just not the animals out there for ‘em to harvest that there should be.

AHTONE: Meyer may not have the ability to prevent climate change himself, or single-handedly control the predator population. But, he’s adapting to the decline in moose by diversify his big game business, adding things like summer camping trips for families.