Herd Reduction

There is no question that there are too many deer in the city of Ann Arbor and surrounding Washtenaw County.
The issue is what to do about it; how to get rid of them?

Deer Reduction Is a Cornerstone of Integrated Deer Tick Management, Journal of Integrated Pest Management, Sept 28, 2017Deer reduction must be considered in any discussion of effective community level intervention to reduce the risk of Lyme disease. There were three main factors that allowed the epidemic to emerge (reforestation, suburbanization, and dense deer herds). Only deer density may be targeted in efforts to reduce, over the long term, the risk landscape to what it was prior to the epidemic. Deer reduction targets tick reproduction without which there is no enzootic transmission cycle. Arguments against the utility of deer reduction as a mode of intervention mistakenly conflate its potential efficacy with the sociopolitical obstacles for implementing such an action.

The Deer in Your Yard Are Here to Stay, CityLab, Aug 7, 2017

    Then the deer came back, swimming across the Arthur Kill and Raritan Bay from New Jersey in search of new habitat. And they reproduced—boy, did they reproduce. An aerial survey of the deer population in 2014 put it at 793. By 2017, the new estimate was between 1,918 and 2,188, an increase of 9,000 percent in just nine years.
    Hungry deer will eat (or trample) almost anything in a garden, becoming a pest for urban and suburban homeowners. Over-browsing by deer depletes the undergrowth of woodland, threatening birds’ habitat and the regeneration of trees. And when deer wander into the road, the results are not so cute. There are about 1.25 million collisions between cars and deer, elk, and moose annually in the United States, according to the insurer State Farm, and these cause around 150 human fatalities, and countless animal deaths, each year.

Hunting Continues to Drive Economic Impact in Michigan, MDNR, Nov 10, 2016This year, more than 525,000 hunters are expected to participate in the annual firearms season for deer which accounts for the largest economic impact of hunting in the state. The DNR estimates more than 90 percent of Michigan hunters will pursue deer this year, with hunters spending an average of 7 days afield during the firearm season. In Michigan, 60 percent of hunters hunt only deer making the upcoming firearm season especially critical for the economy.

Deer Culls, Explained for Those En(deer)ed to Animal Welfare, Daily Gazette, Dec 13 2016There are also significant human costs to excessive deer populations. A 2003 study showed that Lyme disease incidents were reduced by 83% in a residential community following a 92% reduction in the deer population. Lyme disease epidemics occur most frequently in areas with dense white-tailed deer populations. Deer-vehicle collisions are also a risk for densely populated communities. A study of 3 suburban communities has shown that sharpshooting deer populations significantly reduce deer-vehicle collisions. While collisions may not seem like they matter much, from July 1, 2011, to June 30, 2012, deer-vehicle accidents resulted in over $4 billion in costs and 200 human deaths.

Connecticut’s Extremely Efficient Deer-Killer, Courant, Oct 27, 2016It can cost three times as much to capture and sterilize a doe than it does to shoot it.

Comparison of treatment effort for immunocontraceptive vaccines and surgical sterilization in deer, Wildlife Society Bull, Sept 2016[abstract]Fertility control via immunocontraceptive vaccines or surgical sterilization often is considered for the management of deer populations in urban–suburban communities. Immunocontraceptive vaccines have been approved for hand-injection in deer and it has been suggested dart-injection would be more efficient because of added effort associated with live capture. Vaccines currently exhibit nonresponder rates in deer and require booster shots in following years to prolong efficacy, whereas surgical sterilization has 100% efficacy for the entirety of the life of the individual. However, sterilization is considered less efficient because of additional person-hours required during the first year of a project. Therefore, we recorded person-hours required for the capture process (capture, search, and handling) for treating deer via hand-injection and surgical sterilization during winter of 2013, 2014, or 2015 at sites in North Carolina, California, Maryland, New York, and Virginia. The data was recorded for 335 deer across 6 urban–suburban communities. Capture effort consisted of pursuit (i.e., person-hours to acquire shot opportunities) and search and handling (i.e., S&H; person-hours to locate anesthetized deer and vaccinate the individual). On average, 91% and 9% of person-hours were for pursuit and S&H, respectively. Surgical sterilization added an average of 153% to person-hours required for the capture process; however, considering lower efficacy and retreatment requirements of vaccines, sterilization may be more efficient for long-term control of deer in urban–suburban communities. Deer behavior varied across our 6 study sites and affected effort—more approachable deer required less effort to capture and treat with fertility control. Future research should include modelling deer behavior, effort, and efficacy over the long term to identify which situations are best suited for application of vaccine versus sterilization treatments in areas where lethal management of deer is impractical.

Healthy Meat And Clean Kills: Can We Talk About Hunting?, NPR, July 21, 2016

    Kemmerer’s claim that contraceptives could regulate deer numbers across the eastern U.S. is logistically and financially unrealistic, her implication that FWS has done nothing to conserve predators false— counter-examples include black-footed ferrets, Florida panthers, and American crocodiles. And those things said, even in small populations, every deer will die, typically of disease, starvation, or violence dispensed by other deer, predators, vehicles, or hunters. Six decades of field experience with all those options tells me that a quick violent death, however unpleasant to contemplate, usually affords the least suffering. Indeed, I can’t imagine how it could be otherwise, except for those of us and our pets with the luxury of advanced medical care.

    I checked this out with Allen Rutberg of Tufts University’s Center for Animals and Public Policy, who told me by email: “Across the rural and natural landscape, contraception will never be effective at controlling most wildlife populations, at least as long as we need to put a dart in each animal that we need to treat.”

Why Buck-to-Doe Sex Ratios Matter in Your Local Deer Herd, OutdoorLife, June 7, 2016When a doe isn’t initially bred, she will come out of estrus temporarily, but will experience estrus multiple more times during the rut until she is bred. The problem comes when a doe is not bred until the end of the rut. When this happens, the resulting fawns will be born much later than if they had been conceived near the beginning of the doe’s estrus cycle. These late-birth fawns typically have a lower body mass come winter, and in northern climates, are much more susceptible to winter mortality during severe winters.

The pseudoscience of non-lethal deer management, CW Dick Lab, April 17, 2016The Humane Society of America (HSUS) has aggressively promoted these methods in Ann Arbor and elsewhere but their scientific rationale is misleading at best. This post discusses three fallacies at the heart of the HSUS deer program.

Deer Culls in Michigan: Intersection of Science, Policy and Values, Thursday March 3, 2016Kellogg Center, Michigan State University The Environmental Science and Policy Program is starting a Research Colloquia Series that extends the format of the former student research presentations by ESPP specialization students to now include a variety of formats including student and expert panel discussions, faculty roundtables and debates. These events will utilize ESPP’s unique network of MSU expertise spanning MSU’s colleges to address important and timely environmental issues that cross disciplinary boundaries. The ESPP Research Colloquia Series is envisioned as a forum for MSU students, researchers and visitors to engage in research discussions where an interdisciplinary perspective is critical.
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Population Dynamics, The Mississipi State University, Deer LabUnfortunately, determining the number of deer roaming the woods in your particular area can be downright difficult, and sometimes next to impossible. One of the biggest problems is that population size is always changing, hence the name population “dynamics.” Review the basic concepts of deer population dynamics including Deer Population Dynamics, Deer Population Growth, Survival and Reproduction

What Has The Most Impact On Deer Numbers: Bumpers or Bullets?, Simple Hunting, May 2015Hunting is the leading cause of deer mortality in most of the State. Each year, hunters take 40 to 70 percent of the antlered bucks and up to 25 percent of the doe within many areas of Missouri. Hunting, therefore, can be thought of as the primary factor governing the deer population size.

“Models that simulate a deer population under various harvest rates show that harvesting 70 percent of the antlered deer from a herd has little effect on population growth. Harvesting more than 25 percent of the does, however, can cause the population growth to decline.”

Reproductive Performance and Condition of White-Tailed Deer in Ohio, The Ohio Journal of Science, September, 1986 Most pregnant fawn does carried only one fetus; most yearling and adult does carried twins or had triplets.

And a recent Fox News report talks about some of the costs: Taxpayers doling out too much dough to control deer, critics charge, Jan 18, 2014

Forecasting the Effects of Fertility Control on Overabundant Ungulates: White-Tailed Deer in the National Capital Region, PlosOne, December 9, 2015Overabundant populations of ungulates have caused environmental degradation and loss of biological diversity in ecosystems throughout the world. Culling or regulated harvest is often used to control overabundant species. Managers seek to reduce densities of white-tailed deer to decrease harm to native plant communities caused by deer. We present a Bayesian hierarchical model using 13 years of population estimates from 8 national parks in the National Capital Region Network. We offer a novel way to evaluate management actions relative to goals using short term forecasts. Our approach confirms past analyses that fertility control is incapable of rapidly reducing deer abundance.

Deer Reproduction and Localized Management in Indiana, Indiana Inland Steward, Fall 2015The ability for deer to reproduce early and late in life, have multiple offspring each year, and few natural predators, all within ideal habitat, lends itself to growing populations. In modern deer management, knowing the actual number of deer is not as important as knowing how the deer herd is trending. Indiana uses variables including antlered harvest, deer/vehicle collisions, damage reports received, and various surveys to monitor population trends.

Urban Deer Population Control – Direct Methods – Summary Presentation Oak Bay, BC, Jan 12, 2015

Deer Management: Is it true that if you reduce the deer herd they will have triplets, causing a “rebound effect?”, Cleveland Metroparks, 2014This does not occur with deer management programs. Deer reproduction, monitored by Cleveland Metroparks since 1998, has averaged approximately 1.7 fawns per yearling and older does throughout the management period. Twins are the norm with 68% of does bearing twins, 23% having single births, and approximately 4.5% bearing triplets. 4.5% of yearlings or older have not produced fawns.

The problem of exploding deer populations has no attractive solutions, OnScience, Txtwriter, 2013Decreasing the birth rate is certainly the most ethically palatable approach. However, deer birth control has proven impractical. Every female deer must be captured for the first dose, and redarted for each subsequent booster shot. Only in very small isolated populations is this practical. Nor is there any effective oral contraceptive for deer.

Deer: Lethal Approaches, City of Bloomington, IN, 2013 One commonly expressed concern is that hunting actually increases the reproductive rates of deer. That is, when deer are culled, there are fewer deer and those who are left will increase their reproduction to compensate for fewer deer. This happens when a deer population moves from exceeding their biological carrying capacity to a situation in which they are below biological carrying capacity — in other words, if deer go from a denuded landscape to one with abundant forage. Reducing a deer herd that has not reached biological carrying capacity will not enable the remaining deer to go into a “super reproductive” state.
IDNR points out that the real problem with the “rebound effect” occurs when the population comes close to 100% or 110% of biological carrying capacity and reproduction drops to 0.3. The IDNR Deer Research Biologist estimates that deer in Bloomington now are probably reproducing at a 1.5-2.0 rate, and removing deer will not accelerate that rate.

Orphaned Fawns, Pet Deer, and the Right Thing to Do, Ezine@rticles, April 29, 3013Wild animals taken in as pets are no longer wild, yet are never really pets. Once the steps down that road are taken, the animal is in a strange catch-22 situation. It can never be released into the wild because it’s become so dependent on humans that it can never learn to properly take care of itself. Yet, it can’t be properly vaccinated and cared for enough to be anything other than an easy target for passing poachers.

2010: Nontraditional techniques for management of overabundant deer, Anthony DeNicola, Fairfield Ct, Deer Management AllianceNontraditional Techniques include:
1) Controlled Hunts using hunters and usually requiring intensive state agency involvement. Typically preferred by wildlife agencies but it can end up being expensive. Cost $160 -$660 per deer
2) Sharpshooting, which has been used with considerable success- cost varies between $91- $260 per deer
3) Capture and Euthanasia- capture using box or Clover traps and subsequent euthanasia can be relatively expensive
4) Contraception- does not work on free ranging deer
5) Capture and relocation- impractical and inhumane as many deer die of stress postrelease. Also there are no places left that will accept deer.

Attitudes of Urban and Suburban Residents in Indiana on Deer Management, CHAD M. STEWART, Indiana Department of Natural Resources, Wildlife Society Bulletin, 2011Hunting is overwhelmingly accepted as the primary tool by which to manage the deer herd amongst a majority of urban residents. This is a positive finding because most state agencies primarily rely on hunting to manage the deer herd, and it is similar to findings by Kilpatrick et al. (2007).  Stout et al.(1997), however, found that lethal management was not favored amongst most suburban landowners in New York, USA, despite believing that hunting was most effective at managing deer populations.

Lethal & Non-Lethal Deer Management Options, May 26, 2011, University of Maryland Extensiondeer-wildflowers

  • Deer whistles on vehicles do not work and provide a false sense of security.
  • Need to harvest 40-50% of does to maintain population till next year
  • The most economical and practical method of deer population regulation is…

Perspectives on Deer Hunting, R.Young, 1995 rev 2004The white-tailed deer is just another animal, and a prey animal at that, and in order to render decisions regarding its management based on fact rather than impulse and emotion, we must separate ourselves from our memories of Bambi, forget we saw The Yearling, and treat Odocoileus virginianus as dispassionately as we would treat a slug. We want white-tails to survive as a species, but we want them to survive in balance with their environment, not at the expense of it.

Learning by Doing: Deer Management in Urban and Suburban Communities, Human Dimensions Research Unit, Department of Natural Resources, Cornell University, Jan 2004 Lessons Learned: All communities concluded that lethal methods were necessary for reducing deer-related problems. Many communities also concluded that, because of access problems, hunting alone would not be sufficient to manage the deer herd. Consequently, hunting was often used in combination with some other type of lethal control measure. Technical learning took place through two primary mechanisms – gathering and interpreting information before management actions were chosen and learning through experience with managementactions that were implemented.

Attitudes of the Michigan Public and Wildlife Agency Personnel toward Lethal Wildlife Management, Melissa H. Koval and Angela G. Mertig, Wildlife Society Bulletin, March 2004Wildlife agency personnel were more supportive of lethal wildlife management in all situations presented than were members of the public. However, a majority of the public supported each lethal management situation as well. The largest area of disagreement between the 2 groups was in support for lethal management to obtain food. We also assessed differences by demographic and background characteristics. The general public support for lethal management we found suggests that it may be possible for managers to implement lethal wildlife management with few conflicts.

OVERVIEW OF FERTILITY CONTROL IN URBAN DEER MANAGEMENT, in Proceedings of the 2000 Annual Conference of the Society for Theriogenology, pages 237-2462 December 2000

Baring the return of predators, there seem to be five possible solutions:

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