Some Interesting findings in Unit 22 study

[Bryson Bendall]

Perhaps this has already but discussed/ posted on cwt.com before, but I haven't seen it so I figured I'd throw it out there for discussion.

 

http://www.gardnerfiles.com/Arizona%203-Bar%20Study%203-g.pdf

 

This is a link to some info on an ongoing study in the 3-bar wildlife enclosure out in unit 22. Basically, the wildlife biologists involved are focusing on the effect of predators on deer populations in general. The deer are living in the same, rugged, drought conditions as the deer on the outside of the fence yet are experiencing a considerably increased population and fawn survival rate. The ONLY variable that is different is the absence/presence of predators. Its a few years old, so if you know of some more recent info I'd be interested to see it!

 

Maybe this is a no brainer... I mean common sense may tell you that a currently living (i.e. has not gone extinct yet) species of deer living in a desert habitat would probably be plenty prepared to live through any kind of drought conditions, but I have often caught myself blaming the drought conditions for the suffering deer populations, not predation... Obviously you can't blame it on one thing, but I thought this was some interesting stuff to say the least.

So what do you think? Is it a valid study? Can you think of any other variables that might be effecting the population specifically in this study? What do you think really effects our deer populations the most in Arizona and should we be worried?

 

Bryson

 

 

[DesertBull]

I'm pretty sure they let all those deer out of the enclosure a few years ago. Possibly during the 4 peaks fire, so they could escape. Still, the evidence is clear. Predators, including man, take a big toll on deer numbers.

[AntlerObsession]

This is the first time I have read this, and it seems to me that this study doesn't necessarily support predation as the biggest factor. During the wet years there was only a slight increase in fawn survival.

 

I see this study supporting the lack of water source options within a deer's range as the limiting factor. If you know the only place to get water on a mountain is one tank, where are you setting up a blind? Where is every predator for 15 miles going to be? It seems like if a deer has water source options, i.e. Eastern US, they can be picky about where they go.

 

I think it has been stated several times in this forum that if deer have an option between a tank, or rain water caught in a rock depression, deer will choose the depression.

 

Droughts concentrate all the animals within a mile of the one tank in an area that holds water, predators and deer. Who wins the battle at the water hole? My $.02.

[Sir Buckwheat]

Predators take a large toll on game animals today. Here in Utah the "Hay-Day" of Deer Hunting was in the 60's and 70's. During that time fur prices were good, several people trapped and hunted predators and the Government spent a lot of money erradicating them to stop livestock depredation. Fast Forward to today. Fur prices are down, gas prices and cost of living are up. People don't hunt or trap predators like they used to. Also the government is now pro-predator even introducing a new predator to the mix (no not re-introducting, but thats another issue). As a result we have high numbers of coyotes running around, along with higher elk numbers than we've ever had and urban sprawl all equal low deer numbers. This will be the first year ever since I've been old enough to hunt that I will not be hunting deer here in Utah. Several other people I know didn't draw tags either. Its good to see the F&G doing something about it, but sad that its got to this point....

 

Back to the predator issue, when I started working in the oil field 7 years ago you couldn't throw a rock without hitting an antelope. The area had around 3500 head. Today there is only 600-700 animals. What changed? Part is that the oil field has grown but I don't think that takes a big toll on them. The biggest difference I see is that companies no longer allow employees to carry firearms in their trucks for insurance purposes. As a result we went from rarely seeing coyotes to seeing packs as big as 16 dogs! At one point I knew where 5 different packs were and the smallest had 12 dogs in it. These dogs are hard to hunt due to the education they get from idiots that like to blow their calls while at work when they can't shoot them. Also they have been building nesting sights for eagles out here. Between the two the antelope have been hit hard, not to mention the deer population that was here. Some local sportsmen groups have helped by funding the F&G's use of helicopters and planes for shooting coyotes. I know of one state trapper that killed over 500 coyotes this past winter alone. Hopefully those efforts help. Now if we could only de-list raptors so their numbers could be managed...

[dave]

"Sir Buckwheat" That is by far the best handle I have ever seen. Almost an oxymoron. I am laughing out loud. Good thing I check back every year or so and read some of this.

[Sir Buckwheat]

Thanks, its actually the shortened name of a dog I used to have. His registered name was Sir Buckwheat of Spankerdom...My other dog was the Royal Duke of Spankerdom.

[Benbrown]

Predators take a large toll on game animals today. Here in Utah the "Hay-Day" of Deer Hunting was in the 60's and 70's. During that time fur prices were good, several people trapped and hunted predators and the Government spent a lot of money erradicating them to stop livestock depredation. Fast Forward to today. Fur prices are down, gas prices and cost of living are up. People don't hunt or trap predators like they used to. Also the government is now pro-predator even introducing a new predator to the mix (no not re-introducting, but thats another issue). As a result we have high numbers of coyotes running around, along with higher elk numbers than we've ever had and urban sprawl all equal low deer numbers. This will be the first year ever since I've been old enough to hunt that I will not be hunting deer here in Utah. Several other people I know didn't draw tags either. Its good to see the F&G doing something about it, but sad that its got to this point....

 

Back to the predator issue, when I started working in the oil field 7 years ago you couldn't throw a rock without hitting an antelope. The area had around 3500 head. Today there is only 600-700 animals. What changed? Part is that the oil field has grown but I don't think that takes a big toll on them. The biggest difference I see is that companies no longer allow employees to carry firearms in their trucks for insurance purposes. As a result we went from rarely seeing coyotes to seeing packs as big as 16 dogs! At one point I knew where 5 different packs were and the smallest had 12 dogs in it. These dogs are hard to hunt due to the education they get from idiots that like to blow their calls while at work when they can't shoot them. Also they have been building nesting sights for eagles out here. Between the two the antelope have been hit hard, not to mention the deer population that was here. Some local sportsmen groups have helped by funding the F&G's use of helicopters and planes for shooting coyotes. I know of one state trapper that killed over 500 coyotes this past winter alone. Hopefully those efforts help. Now if we could only de-list raptors so their numbers could be managed...

 

Here is a study in the real world, not deer pens--lots of studies show that fawn survival (the number of fawns at heel in fall or winter censuses) are higher in areas that were subject to intensive predator control. The rub is that none of these studies even suggest much less document the successful recruitment of these fawns into the adult population. Mortality in deer is compensatory: yearlings are going to die at about the same rate, regardless of increased predation or declines in predation.

 

 

 

Wildlife Monograph

 

Demographic response of mule deer to experimental reduction of coyotes and mountain lions in southeastern Idaho

 

Réponse Démographique du Cerf Mulet à la Réduction Expérimentale des Populations de Coyotes et de Pumas dans le Sud de l'Idaho

 

Mark A. Hurley1,*,

James W. Unsworth2,

Peter Zager3,

Mark Hebblewhite4,

Edward O. Garton5,

Debra M. Montgomery5,

John R. Skalski6,

Craig L. Maycock7

Article first published online: 2 AUG 2011

 

DOI: 10.1002/wmon.4

 

Copyright © 2011 The Wildlife Society.

 

Issue

 

 

Wildlife Monographs

 

Volume 178, Issue 1, pages 1–33, August 2011

 

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Abstract

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Keywords:

 

alternate prey;

Canis latrans;

climate;

coyote;

mortality;

mountain lion;

mule deer;

Odocoileus hemionus;

predator control;

Puma concolor;

survival analysis

Abstract

 

Manipulating predator populations is often posed as a solution to depressed ungulate populations. However, predator–prey dynamics are complex and the effect on prey populations is often an interaction of predator life history, climate, prey density, and habitat quality. The effect of predator removal on ungulate and, more specifically, mule deer (Odocoileus hemionus) populations has not been adequately investigated at a management scale. We tested the efficacy of removing coyotes (Canis latrans) and mountain lions (Puma concolor) for increasing survival and population growth rate of mule deer in southeastern Idaho, USA, during 1997–2003. We assigned 8 game management units (GMUs) to treatments under a 2 × 2 factorial design (treatments of coyote removal and lion removal) with 2 replicates of each treatment or reference area combination. We used methods typically available to wildlife managers to achieve predator removals and a combination of extensive and intensive monitoring in these 8 GMUs to test the hypothesis that predator removal increased vital rates and population growth rate of mule deer. We determined effects of predator removal on survival and causes of mortality in 2 intensive study sites, one with coyote and mountain lion removal and one without. We also considered the effects of other variables on survival including lagomorph abundance and climatic conditions. In these 2 intensive study areas, we monitored with radiotelemetry 250 neonates, 284 6-month-old fawns, and 521 adult females. At the extensive scale, we monitored mule deer population trend and December fawn ratios with helicopter surveys. Coyote removal decreased neonate mortality only when deer were apparently needed as alternate prey, thus removal was more effective when lagomorph populations were reduced. The best mortality model of mule deer captured at 6 months of age included summer precipitation, winter precipitation, fawn mass, and mountain lion removal. Over-winter mortality of adult female mule deer decreased with removal of mountain lions. Precipitation variables were included in most competing mortality models for all age classes of mule deer. Mountain lion removal increased fawn ratios and our models predicted fawn ratios would increase 6% at average removal rates (3.53/1,000 km2) and 27% at maximum removal rates (14.18/1,000 km2). Across our extensive set of 8 GMUs, coyote removal had no effect on December fawn ratios. We also detected no strong effect of coyote or mountain lion removal alone on mule deer population trend; the best population-growth-rate model included previous year's mountain lion removal and winter severity, yet explained only 27% of the variance in population growth rate. Winter severity in the current and previous winter was the most important influence on mule deer population growth. The lack of response in fawn ratio or mule deer abundance to coyote reduction at this extensive (landscape) scale suggests that decreased neonate mortality due to coyote removal is partially compensatory. Annual removal of coyotes was not an effective method to increase mule deer populations in Idaho because coyote removal increased radiocollared neonate fawn survival only under particular combinations of prey densities and weather conditions, and the increase did not result in population growth. Coyote-removal programs targeted in areas where mortality of mule deer fawns is known to be additive and coyote-removal conditions are successful may influence mule deer population vital rates but likely will not change direction of population trend. Although mountain lion removal increased mule-deer survival and fawn ratios, we were unable to demonstrate significant changes in population trend with mountain lion removal. In conclusion, benefits of predator removal appear to be marginal and short term in southeastern Idaho and likely will not appreciably change long-term dynamics of mule deer populations in the intermountain west. © 2011 The Wildlife Society.

[Benbrown]

Summary of another study by the Western Association of Fish and Wildlife Agences:

 

Analysis examines, makes recommendations regarding federal-state collaboration in mule deer management, energy development, focuses on Green River Basin.

 

WASHINGTON – The Theodore Roosevelt Conservation Partnership today released a comprehensive report analyzing the federal government’s policy approach to managing energy development while promoting and conserving mule deer populations in the American West.

 

“Mule Deer and Energy: Federal Policy and Planning in the Greater Green River Basin” examines collaborative efforts in mule deer management between federal land agencies and state wildlife agencies, offering insights into federal management of the species and its habitat during public-lands energy development. The report focuses on the greater Green River Basin, home to some of the most significant mule deer herds in North America as well as many of the nation’s largest energy reserves. It studies the conflicts resulting from the coexistence of these valuable resources and presents specific recommendations for resolving them.

 

“We need more and better coordination for meeting management objectives and better integration of known science in the management of these cornerstone mule deer populations,” said Steve Belinda, director of the TRCP Center for Responsible Energy Development. “This report offers an opportunity to look ahead and do better – both for mule deer herds in the Green River Basin and across the West.”

 

Icons of the western United States, mule deer are related to white-tailed deer but have different habitat requirements and respond differently to human-caused disturbance. While white-tailed deer are highly adaptable, mule deer rely on specific seasonal habitats that enable annual migrations between summer and winter range, the latter being a major limiting factor for the species and typically protected from disturbance. Most winter range is closed to vehicle traffic and human activity to safeguard mule deer populations, and energy leases located within winter range often have restrictions on development.

 

The greater Green River Basin of southwestern Wyoming, northwestern Colorado and northeastern Utah comprises 10.2 million acres of mule deer crucial winter range on Bureau of Land Management and U.S. Forest Service lands. Of this total, 2.4 million acres already have been leased for development. The TRCP report notes that, while seasonal restrictions intended to protect mule deer from additional stress are in place, industry often asks for and receives relief from them. In Wyoming, for example, 83 percent of requests for relief from wildlife protections were approved in an 18-month period in 2007-2008.

 

“More than 15,000 wells already have been drilled in mule deer crucial winter range,” said Belinda. “To date, most of this activity has taken place outside of the critical winter season. But how long these protective measures will continue to be applied is unknown. Industry has made no secret of its belief that these measures, which are intended to protect deer and other wildlife, are unnecessary and impediments to development.

 

“In the Pinedale Anticline in southwestern Wyoming,” continued Belinda, “mule deer have declined more than 60 percent in the last 10 years, and the BLM has increasingly authorized development on crucial winter ranges year-round. We can do better for mule deer during energy development, but we must better integrate the science, better plan for mitigation, and formulate an overall plan for managing mule deer habitat.

 

“Overall we found inconsistencies across all jurisdictions regarding how state mule deer plans are incorporated into federal plans and energy projects,” stated Belinda, a former BLM biologist. “We also found that energy development is the dominant priority for BLM policy and planning within the Green River Basin, that mule deer science often is ignored or misinterpreted, and that coordination between habitat managers and state deer managers is weak, if it occurs at all.”

 

“The need for greater coordination is the lesson learned from this report,” said Miles Moretti, president and CEO of the Mule Deer Foundation, which is a member of the TRCP Fish, Wildlife and Energy Working Group, “coordination not just between federal and state entities but among all stakeholders. We have the power to address deficiencies in management that have negatively affected this prized sportsmen’s resource – and to forge a brighter future for mule deer.”

 

Read “Mule Deer and Energy: Federal Policy and Planning in the Greater Green River Basin.”

 

Review a summary of the TRCP report and recommendations.