The Deer Decline in Colorado

mule deer
Given that I moved from the east coast where there are too many deer, who seem to be getting along with housing development, I thought this Denver Post article was interesting.

Below is an excerpt:

In Colorado, the latest CPW population estimates, provided in response to Denver Post queries, show a statewide decline in mule deer — the main deer in the West — down to 390,600 in 2013 from 614,100 in 2005.

Some of the decline may be because of changes in methods for estimating deer populations.

Across western states, deer decreased by about 10 percent overall between 2003 and 2009, said Arizona-based wildlife biologist Jim Heffelfinger, who chairs the Western Association of Fish and Wildlife Agencies’ Mule Deer Working Group, which draws expertise from 23 states and Canadian provinces.

Deer aren’t likely to join polar bears facing extinction, but the sharp downward trend requires concerted human action, Heffelfinger said.

“We certainly cannot have it all. We need to be smart about our wildlife habitat, especially our mule deer habitat and how we manage the population,” Heffelfinger said. “There are so many different things that are stressing mule deer around the West. Fire suppression has closed the forest canopies, and that has reduced the amount of shrubs and weeds that deer rely on.

“You don’t really like big, catastrophic fires — certainly where human structures are damaged. But we really need to open up the canopies for deer.”

It’s interesting the lengthy list that they came up with for possible causes..

Colorado-based wildlife biologists have pinpointed multiple factors driving deer declines:

• a one-two punch of hard winters followed by drought;

• commercial and residential development in the mountains;
Mule deer make their way across the fencing in an area of the Rocky Mountain Arsenal.
Mule deer make their way across the fencing in an area of the Rocky Mountain Arsenal. (Kathryn Scott Osler, Denver Post file)

• chronic wasting disease;

• aggressive fire suppression that leads to overly thick forests;

• coyote and mountain lion predation;

• more than 2,000 vehicle collisions a year in western Colorado;

• energy development that disrupts deer habitat and migration.

In response to the multi-year decline, Colorado wildlife managers have reduced the number of deer hunting licenses they offer from 130,106 in 2007 to about 80,000 for this year.

Hunters in Colorado kill 35,000 to 40,000 deer a year, said Chad Bishop, CPW assistant director for wildlife natural resources.

As well as the “change in method of estimation.” I’d be interested in hearing what other states think. Seems like if the reduction is westwide, all the possible factors would have different levels of occurrence in different states.

2 thoughts on “The Deer Decline in Colorado”

  1. The East has its own lessons for the West when it come to deer herd management (or, more accurately non-management). Born and bred in Pennsylvania (Penn State ’43) I well remember the problems with white-tail overpopulation, which continue to this day. These “pests” multiplied hugely in the years following the widespread early logging that resulted in vast areas of early successional (aka prime wildlife) habitat. As these secondary forests aged and their density increased, fire exclusion and lack of harvesting plus the strong reproductive capacity of the species has resulted in a situation so dire that, as one observer hyper-ventilated “… it’s hard to think of a more insidious threat to forests, farms and wildlife, not to mention human health and safety, than deer.” (Bloomberg View. (2012, August 8). Deer infestation calls for Radical Free-Market Solution. – See more at: In Pennsylvania, some 40,000 deer were killed in 2009 by autos.

    All this suggests that non-management of our forest resources, be they in the East or in the West, as is now the norm on public lands and as advocated by ecocentric environmental activists, results in disaster.

  2. Mule deer have a completely different “nature” than whitetails. They are certainly less comfy around humans than whitetails are. They eat different stuff, too. On balance, it seems to me that whitetails are rather braver (or dumber) than mule deer, but they also seem to be more aggressive and in direct competition with mulies, whitetails seem to win the habitat when both species find it desirable.
    Kinda like spotted owls versus barred? Classy people versus mullets?


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