Impacts of Impacts of Predation on Mule Predation on Mule

Deer in UtahDeer in Utah

OutlineOutlinePredator Management PolicyWhen is Predator Management EffectivePredator Ecology and Impacts on Deer:

BearsCougarsCoyotes

Deer Recovery

Criteria for the Consideration of a Criteria for the Consideration of a Unit Predator Management PlanUnit Predator Management Plan

• When a transplant or reintroduction of wildlife susceptible to predation (e.g. bighorn sheep, Black-footed ferret….) will occur in the next year

• When big game populations on a management unit or

subunit are below 65% of management objective

• When big game populations on a management unit or subunit are below 75% of management objective and are stable or decreasing for 3 consecutive years

• When bighorn sheep populations on a unit or subunit are below 90% of management objective

• When big game populations are below viable levels (e.g. bighorn sheep < 125).

Criteria for the Consideration of a Criteria for the Consideration of a Unit Predator Management PlanUnit Predator Management Plan

• When big game sex ratios or average age class objectives of prey populations are below unit objectives.

• When predators are significantly impacting Sensitive Species populations (e.g. predator control to protect sage-grouse, Utah Prairie dogs, Black-footed ferret or other Sensitive Species populations).

• In addition, when a prey population is chronically below unit management plan objective, that objective will be reviewed as it relates to the carrying capacity of the habitat.

• Currently revising criteria to consider Fawn:Doe and Adult Survival Data

When does Predator When does Predator Management Work? Management Work?

Deer populations are well below objective – habitat is not limiting

Predation is identified as a limiting factor – predation is additive

Control efforts reduce predator populations enough to yield results (e.g. 70% of local coyote population)

Control efforts are timed to be most effective (prior to predator or prey reproduction)

Control occurs at a focused scale

Black BearsBlack Bears

Black Bear Predation on Mule Deer

Black bears rarely kill adult deer or elk.

Mule Deer survival studies In a recent study in north central New Mexico 3% of

mule deer fawn mortalities were attributed to black bears (Lomas and Bender 2007).

In a recent study in west central Colorado 4% of fawn mortalities were attributed to black bears (Pojar and Bowden 2004).

Studies in Montana (Hamlin et al. 1984), Oregon (Trainer 1975), and Idaho (Hurley and Unsworth 2001) all reported less than 5% of fawn mortalities were attributed to black bears.

Schlegal (1976) found that 73% of elk calf Schlegal (1976) found that 73% of elk calf mortalities in northern Idaho were attributed to mortalities in northern Idaho were attributed to black bearsblack bears

Black Bear predation on Mule Deer in Utah

LaSal Mtn Study (Smith 1983)72% fawn mortality

Bears accounted for 18% of the predation and 13% of the mortality

Book Cliffs Study (Karpowitz 1984)37% fawn mortality

No mortalities attributed to bears

ConclusionBlack bear predation can have a

significant impact on elk fawn survival, but the impact of black bears on mule deer fawn survival seems to be relatively low

CougarsCougars

Cougar Research in UtahLindzey et al. Boulder Mtn. Study 1979-1987

Mule deer comprised 81% of their dietRabbits, large rodents and smaller predators

were also important prey itemsLivestock comprised < 1% of the dietCougar density stabilized at a level below that

set by prey abundance

Wolfe et al. (1995 – Present) Oquirrh / MonroePrey Composition - 23 Cougars, 501 kills

89% Mule Deer (55% Does, 45% bucks, 68% adults), 4% Elk

Cougar Research in Utah

Wolfe et al. (1995 – Present) Oquirrh / MonroeEffects of harvest – Hunted vs Non-hunted

4 years of liberal harvest on the Monroe Mtn resulted in > 60% decline in density – Oquirrh Mtn. (Kennecott) population remained stable

What happened to the Deer Populations on the Monroe Mtn?Deer populations on Monroe Mtn showed little or no Deer populations on Monroe Mtn showed little or no

response to the decreased cougar densitiesresponse to the decreased cougar densities

Cougar Predation on Ungulates in Utah

LaSal Mtn Study (Smith 1983) 72% fawn mortality

Cougars accounted for 4% of the predation and 3% of the mortality

Book Cliffs Study (Karpowitz 1984) 37% fawn mortality

Cougars accounted for 22% of the predation and 13% of the mortality

Oak Creek Study (Robinette 1957) 33% Fawn mortality (Birth – October)

Predation accounted for 41% of the mortality – no breakdown by predator, but coyotes were assumed to be the primary cause

Statewide Mule Deer Survival Study (2009 – Statewide Mule Deer Survival Study (2009 – Ongoing)Ongoing) Preliminary resultsPreliminary results

Adult Doe Mortality – 14%Adult Doe Mortality – 14% Fawn Mortality – Fawn Mortality – 48%48%

Predator Management Efforts Focused on Cougars

Currently 22 out of 49 predator management units are under predator management plans for cougars

Last recommendation cycle tags / quotas were increased by 13% on cougar units under PMPs

Harvest data indicates that the statewide Harvest data indicates that the statewide cougar population was decreased in late 1990’s cougar population was decreased in late 1990’s and early 2000’s and is currently being held at and early 2000’s and is currently being held at a reduced levela reduced level

Statewide Cougar Harvest 1989-2010

0

100

200

300

400

500

600

700

800

900

1,000

Year

Harvest Objective Quota

Limited Entry Permits

Sport Harvest

ConclusionCougar predation can impact adult survival in

mule deer populations, but currently adult survival does not appear to be a limiting factor for most deer herds in Utah14% adult doe mortality

CoyotesCoyotes

Coyotes Coyotes unprotected and not managed by the Division.

Coyotes are omnivorous and opportunistic generalists.

Coyotes have been documented consuming ungulates, small mammals, birds, reptiles, fish, amphibians, insects, fruits, grasses, and various types of other vegetation (Meinzer et al. 1975, Green and Flinders 1981, Bowyer et al. 1983, Bleich 1999, Pierce et al. 2000, Bright and Hervert 2005).

Shannon et al. (2009) found that coyotes increased Shannon et al. (2009) found that coyotes increased consumption of ungulates during drought years, likely a consumption of ungulates during drought years, likely a result of young being in poor condition and a decline in result of young being in poor condition and a decline in rabbit and rodent densities.rabbit and rodent densities.

Coyotes

Where predation was thought to be a limiting factor on mule deer, coyote predation has been implicated as a significant cause of mortality where telemetry or experimental manipulations were used in research (Multiple studies summarized by Ballard et al. 2001).

Generally, coyotes impact fawn survival more so than adult survival (Multiple studies summarized by Ballard et al. 2001).

Coyote Predation on Ungulates in Utah

LaSal Mtn Study (Smith 1983) 72% fawn mortality

Coyotes accounted for 50% of the predation and 36% of the mortality

Book Cliffs Study (Karpowitz 1984) 37% fawn mortality

Coyotes accounted for 78% of the predation and 44% of the mortality

Oak Creek Study (Robinette 1957) 33% Fawn mortality (Birth – October)

Predation accounted for 41% of the mortality – no breakdown by predator, but coyotes were assumed to be the primary cause

Statewide Mule Deer Survival Study (2009 – Ongoing) Preliminary results

Adult Doe Mortality – 14%Fawn Mortality – 48%

Coyote Control EffortsCoyote Control EffortsTiming and location of coyote control Timing and location of coyote control

determines effectivenessdetermines effectiveness Timing

January - March Breaks-up coyote pairs and eliminates reproduction

May - June removes coyotes prior to and during deer fawning

Coyotes killed before February and after June have little impact Research indicates that pair bonds are reestablished within

weeks Location

Units where deer herds are < 75% of objective and/or F:D ratios are < 60 – PMP Policy

Focused on specific fawning grounds within the unit – Coordinated between DWR regions and WS personnel

Currently 30 out of 49 predator management units Currently 30 out of 49 predator management units are under predator management plans for coyotesare under predator management plans for coyotes

Coyote Control EffortsCoyote Control EffortsWildlife Services Wildlife Services

HarvestHarvest Sport HarvestSport Harvest

YearYearDeer Deer

ProtectioProtectionn

Livestock / Livestock / OtherOther

TrappiTrappingng

HuntinHuntingg

TotalTotal

07/0807/08 2,5742,574 3,0443,044 4,0554,055 3,5823,582 13,25513,255

08/0908/09 1,9321,932 1,9771,977 3,9633,963 2,9822,982 10,85410,854

09/1009/10 1,7311,731 3,8083,808 3,1883,188 2,9552,955 9,9519,951

ConclusionCoyotes can substantially impact mule

deer fawn survival – Fawn survival appears to be a limiting factor to population growth in Utah48% fawn mortality

SummaryWe have an aggressive predator management

program in Utah (nearly $500,000 annually for predator control). Additional $350,000 committed for FY11 and FY12

We are addressing the predation and habitat aspects relative to deer recovery in Utah.

If predators are a limiting factor to deer recovery If predators are a limiting factor to deer recovery in Utah evidence suggests that coyotes are the in Utah evidence suggests that coyotes are the most likely culpritmost likely culprit 48% fawn mortality48% fawn mortality 14% adult doe mortality14% adult doe mortality

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