Mule deer decline

Oak

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OMG, you mean coyotes aren't killing all the deer?!?!?!?

This should probably be in SI, but more people will read it here.

_______________________________________________________________________


Changes weigh on mule deer

By Charlie Meyers
Denver Post Outdoors Editor
DenverPost.com
http://www.denverpost.com/rec/ci_4153020

As far as mysteries go, the challenges posed by the recent mule deer study in northern New Mexico wouldn't have caused much consternation for Sherlock Holmes.

After all, it doesn't take much sleuthing to come up with a direct link between poor diet and survival, particularly when it involves fawn mortality. But the Santa Fe Trail Mule Deer Adaptive Management Project, STAMP for short, breaks new ground in detailing the way continuing environmental change plays a telling role in mule deer decline across the Rocky Mountain West.

For openers, it's the largest mule deer research performed in the U.S. on private property, covering 1.3 million contiguous acres in northern New Mexico, generally west of Raton. Then there's the way the study, conducted from December 2001 through 2004, was able to give hard science to things that previously had been speculation.

Game managers for years have sought reasons why mule deer populations have nosedived in nearly every state over a period spanning almost four decades. The popular list includes predation, competition from elk and changes in habitat.

The STAMP study diminishes the first two factors while lending more distinct features to the third. In this way, it echoes similar findings in a continuing Colorado Division of Wildlife study on the Uncompahgre Plateau, west of Montrose.

"The key factor for survival and productivity of any large herbivore is body condition, how much body fat they can build up," said Dr. Lou Bender of New Mexico State University, the lead researcher.
For example, most animals tested were in poor condition, with about 6-8 percent body fat against an optimum three times that level. This made survivability tenuous at best for doe deer and almost impossible for fawns, Bender said.

The findings include:
  • If does don't get enough to eat, they don't provide sufficient nutrition for fawns to grow, both before and after birth.
  • In such cases, fawns that were born generally weren't killed by predators but rather died shortly thereafter.
  • Fawns tend to be born small and later in the year, often in late July and early August, a month later than optimum. This spells double trouble for survivability.
  • Not surprisingly, drought plays a key role. In 2002, the study found that one-third of adult deer died and no fawns were recruited into the population.
This aspect of drought is even more significant for a borderline desert environment in which plant recovery occurs slowly, if at all. But these changes in habitat go far beyond water cycles.

Declining populations largely reflect a loss of the habitat favored by mule deer, which is shrubland.
Among the conclusions:
  • Livestock-oriented grassland increasingly replaced the shrubs that deer prefer to eat.
  • A suppression of fire allowed dense forests to gain dominance with the same result. Periodic fire is an important factor in rejuvenating shrubs.
  • Most important, a rapid expansion of drought-resistant pinon and juniper sharply reduces available forage. Once established in dense stands, juniper blocks sunlight and rain from reaching the ground and nothing grows beneath it.
"The more pinon-juniper that was included in that doe's home range, the poorer her body condition," Bender said.

A key component in recovering habitat would be controlling piñon-juniper, but not eliminating it, Bender said. These evergreens also provide important survival cover.

The reality, Bender said, is "... that we are never going to get back to the population levels that people remember from the '50s, '60s and even '70s."
The first phase of the Uncompahgre study, conducted as a comparison to companion research by the Idaho Department of Fish & Game, reached a similar conclusion both on predation and survival.

Colorado officials used pellets to supplement the diet of select doe deer while using no predator control. Meanwhile, their Idaho counterparts conducted an intensive campaign against coyotes and mountain lions in their study area. Deer provided this nutritional boost demonstrated a high rate of survival, sufficient for a population increase of about 20 percent a year, said Dave Freddy, DOW mammals research leader. At the same time, the Idaho predator control yielded little change in doe-fawn survival. A second phase of the Uncompahgre study involves extensive habitat changes, primarily in removing pinon and juniper. Results should be known in five to seven years.
 
thanks for passing on the info,very interesting to a non westerner.No problem here in Iowa with food.In fact I almost don't like to shoot a doe because of all the fat that I'll have to trim off.
 
This study shows the opposite of the 3 Bar Study done here in Arizona. Maybe we better do another study. Should we go for 2 out of 3, or 3 out of 5? Maybe it is different for different parts of west?
 
We had a mule deer summit here about 10 years ago to see what could be done to the downward trend in mule deer numbers.The DFW&P has always had a policy to issue more tags if they thought that a die-off was imminent.

I testified that when we knew the mule deer were going to crash, that instead of issuing more tags, we'd issue less or reduce the sales of doe tags altogether, and that we would call this new form of action "game management".

I was, and always will be amazed that on private property, the bug that's flying around in the air killing the deer on public lands isn't as peril avent.

The lead fly.
 
HuntnFool said:
This study shows the opposite of the 3 Bar Study done here in Arizona. Maybe we better do another study. Should we go for 2 out of 3, or 3 out of 5? Maybe it is different for different parts of west?


Kinda strange how Mexico still has a stable mule deer population even with the drought.
 
Wonder if we had more of a domestic sheep industry if we wouldn't have more deer.

Livestock-oriented grassland increasingly replaced the shrubs that deer prefer to eat.
A suppression of fire allowed dense forests to gain dominance with the same result. Periodic fire is an important factor in rejuvenating shrubs.
Most important, a rapid expansion of drought-resistant pinon and juniper sharply reduces available forage. Once established in dense stands, juniper blocks sunlight and rain from reaching the ground and nothing grows beneath it.

These are vital components for domestic sheep as well. Those bottom two are defintely the main cause in a large portion of NW UT that I've been working in for the last two months.
 
Colorado officials used pellets to supplement the diet of select doe deer while using no predator control. Meanwhile, their Idaho counterparts conducted an intensive campaign against coyotes and mountain lions in their study area. Deer provided this nutritional boost demonstrated a high rate of survival, sufficient for a population increase of about 20 percent a year, said Dave Freddy, DOW mammals research leader. At the same time, the Idaho predator control yielded little change in doe-fawn survival. A second phase of the Uncompahgre study involves extensive habitat changes, primarily in removing pinon and juniper. Results should be known in five to seven years.
@Oak stumbled across this old thread. Curious if there was another article about the findings 5 to 7 years later?
 
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