Presentation is loading. Please wait.

Presentation is loading. Please wait.

Mule Deer Plan Population Objective Strategy c. Manage predators on all units that are chronically below objective, and habitat is not limiting, according.

Similar presentations


Presentation on theme: "Mule Deer Plan Population Objective Strategy c. Manage predators on all units that are chronically below objective, and habitat is not limiting, according."— Presentation transcript:

1 Mule Deer Plan Population Objective Strategy c. Manage predators on all units that are chronically below objective, and habitat is not limiting, according to the current predator management policy

2 Predator Management Policy When is Predator Management Effective Predator Ecology and Impacts on Deer: Bears Cougars Coyotes Deer Recovery

3 Predator Management May Occur But Is Not Limited To The Following Circumstances: 1. In localized areas where introductions or transplants of potentially vulnerable wildlife species (e.g., bighorn sheep, wild turkeys, Utah prairie dogs, and black-footed ferrets) has occurred or is imminent…… 2. When prey populations are unable to meet management goals and objectives and predation plays a significant role. 3. When an individual predator is consistently preying on sensitive prey populations (e.g. when an individual cougar is consistently preying on a group of bighorn sheep). 4. On wildlife waterfowl management areas, especially those primarily managed for specific species and predation is significantly affecting the population.

4 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).

5 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.

6 Compensatory Mortality – Reduction in one form of mortality results in an increase in another form of mortality (e.g. decrease in predation results in an increase in disease) Compensatory mortality takes place when habitat is the primary limiting factor Additive Mortality – Reducing mortality results population increases Additive mortality takes place when habitat is not limiting

7 Kill rates are often quoted, but offer little to understanding predator/prey relationships if habitat limitations are unknown Example: the phrase “cougars will eat a deer a every 10 days” may be true, but it may or may not impact the population based on if the mortality is additive or compensatory.

8 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

9

10 Black bears are omnivores and extremely opportunistic % of the bear diet consists of available roots, tubers, bulbs, berries, succulent leaves, grasses and nuts (acorns and pine nuts). Up to 20% may be amphibians, reptiles, small mammals, fish, ants and other insects. Usually about 10% is carrion (flesh from dead animals). Usually about 10% is carrion (flesh from dead animals).

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

12 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

13 Black 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

14

15 Cougars are solitary obligate carnivores that consume deer-sized prey throughout their range (northern Canada to southern tip of So. America) Deer and elk comprise the majority of the diet in forested areas of western No. America Bighorn sheep are a significant prey for individual cougars in certain areas Important secondary prey include: rabbits, porcupine, beaver and marmots Generally, Cougars impact adult survival and not fawn survival

16 Lindzey et al. Boulder Mtn. Study Mule deer comprised 81% of their diet Rabbits, large rodents and smaller predators were also important prey items Livestock comprised < 1% of the diet Cougar density stabilized at a level below that set by prey abundance Wolfe et al. (1995 – Present) Oquirrh / Monroe Prey Composition - 23 Cougars, 501 kills 89% Mule Deer (55% Does, 45% bucks, 68% adults), 4% Elk

17 Wolfe et al. (1995 – Present) Oquirrh / Monroe Effects 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 Sport harvest is a viable tool for reducing cougar densities What happened to the Deer Populations on the Monroe Mtn? Deer populations on Monroe Mtn showed little or no response to the decreased cougar densities Deer populations on Monroe Mtn showed little or no response to the decreased cougar densities

18 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 – Ongoing) Statewide Mule Deer Survival Study (2009 – Ongoing) Preliminary results Preliminary results Adult Doe Mortality – 12% Adult Doe Mortality – 12% Fawn Mortality – 45% Fawn Mortality – 45%

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

20

21 Cougar predation can impact adult survival in mule deer populations, but currently adult survival does not appear to be a limiting factor to deer herds in Utah 12% adult doe mortality

22

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

24 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).

25 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 – 12% Fawn Mortality – 45%

26 Timing and location of coyote control determines effectiveness Timing and location of coyote control determines effectiveness Timing February - April Breaks-up coyote pairs and eliminates reproduction 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 – 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 are under predator management plans for coyotes Currently 30 out of 49 predator management units are under predator management plans for coyotes

27 Wildlife Services Harvest Sport Harvest Year Deer Protection Livestock / Other TrappingHuntingTotal 07/082,5743,0444,0553,58213,255 08/091,9321,9773,9632,98210,854 09/101,7313,8083,1882,9559,951

28 Coyotes can substantially impact mule deer fawn survival – Fawn survival appears to be a limiting factor to population growth in Utah 45% fawn mortality

29 We have an aggressive predator management program in Utah (nearly $500,000 annually for predator control). We are addressing the predation and habitat aspects relative to deer recovery in Utah. If predators are a limiting factor to deer recovery in Utah evidence suggests that coyotes are the most likely culprit If predators are a limiting factor to deer recovery in Utah evidence suggests that coyotes are the most likely culprit 45% fawn mortality 45% fawn mortality 12% adult doe mortality 12% adult doe mortality

30


Download ppt "Mule Deer Plan Population Objective Strategy c. Manage predators on all units that are chronically below objective, and habitat is not limiting, according."

Similar presentations


Ads by Google