Dwindling moose populations are perplexing scientists in other parts of the country. However, wildlife experts say the number of moose around Summit County, and the rest of Colorado, remains stable.
Biologists have noted declines in moose populations in British Columbia, Minnesota, Montana and as close as southern Wyoming. But whatever is causing that trend hasn’t seemed to impact moose herds in Colorado.
“There appears to be a pretty significant reduction in moose populations, and it’s a fairly widespread situation,” said Brad Petch, northwest senior wildlife biologist for Colorado Parks and Wildlife. “While there have been a number of explanations proposed, from habitat loss and disease issues, it’s still up in the air.”
The question of climate change has also come up in discussions regarding moose decline.
“Large-scale climate change is often batted around when these kinds of populaton declines occur, and has been an increasing part of the discussion,” Petch said.
But quantifying climate change is a difficult thing to do, he said.
Montana’s Department of Fish, Wildlife and Parks researcher Nick DeCesare is taking part in a 10-year study looking into the problem. DeCasare said he has a few different hypotheses about why moose populations in Montana have been in decline for the last 15-20 years. Among the concerns are parasites, including winter ticks and an arterial worm.
“We are watching to see if that is having an impact,” DeCasare said.
He, too, cited climate change as potential trigger for the problem.
“I’m not sure if it’s having a direct impact, or if it can have an impact on parasites — making them more prevalent because of changes in the climate,” he said.
Other factors Montana wildlife biologists are looking into are predation and hunting.
“We have more wolves and bears on the landscape than we had 20 years ago,” DeCasare said. “We are also looking at our own effects from hunting.”
DeCasare said he isn’t sure why some North American moose populations are declining, while others remain strong.
“There isn’t one overarching trend driving moose dynamics all over. There are different stories going on in each place,” DeCasare said. “Even within Montana, we have different factors regulating different populations.”
Colorado wildlife biologist Petch said he agrees there’s no clear reason as to why Colorado moose populations remain steady while others are thinning. There are, however, some factors that make Colorado moose populations unique.
Moose populations in the state are very young. They were transplanted to Colorado’s North Park region near Walden for hunting purposes in the late 1970s. Since then, moose have thrived and expanded their range. The number of moose statewide is now estimated to be about 2,000.
In Colorado, the largest herd is found in the North Park area, but there are also herds in areas around the Laramie River, Middle Park, San Juan, Grand Mesa, White River and the Front Range.
Moose populations really took off after the animals were introduced in North Park, but numbers haven’t increased a lot in recent years.
“We still have an upward trend but it’s pretty slight,” Petch said.
Colorado scientists have noted a decline in birthrates, including the number of twin moose calves being born.
“You start to see that drop as habitat begins to fill up,” Petch said.
Moose in Colorado seem to be adapting well to the diverse mountain climate — dwelling in habitat you don’t normally see in other parts of the country.
“We have a diverse habitat base and that equals lots of opportunity for moose,” Petch said.
Most moose live in forested areas that are often close to lakes, rivers and marshes. But Colorado moose, particularly the ones living around Grand Mesa, are acclimating to a different environment, Petch said. “We see them using different habitats, in oak brush, side hills and steeper slopes, to an extent that’s not found in other states.”
Although moose were brought to the state for hunting purposes, that activity is closely monitored today, Petch said.
“The number of licenses in total is very limited,” he said. “In North Park, our big herd, run just under 100 licenses for about 550 moose.”
While moose are popular for both hunting and viewing in Colorado, they can be dangerous.
“There have been some moose incidents in the news this year, and there is a common thread among those — each of those incidents involves a dog,” Petch said.
Wolves are one of the few animals that prey on moose, which make no distinction between the predator and the house pet.
“When they see a dog it triggers instinctive behavior,” Petch said.
People who walk their dogs in moose country should be very aware of their surroundings. Petch said if hikers stumble upon a moose, they should keep their distance, and if the see a moose exhibiting agitated behavior, back away.
“While there have been a number of explanations proposed, from habitat loss and disease issues, it’s still up in the air.”
Colorado Parks and Wildlife