The Effect of Hunting on Deer Reproduction and Urban Deer Management
Light to Moderate Hunting Does Not Reduce the Deer Population Over Time in an Otherwise Stable Environment
Deer production at Hopland Field Station
Guy E. Connolly, University of California
William M. Longhurst, University of California
California Agriculture 29(6):8-9. DOI: 10.3733/ca.v029n06p8. June 1975.
Abstract: Hunters and research workers took 2,267 deer from the 5,000-acre Hopland Field Station in southeastern Mendocino County from 1951 through 1974. About half of the deer were bucks taken by hunters and the remainder were antlerless deer shot or trapped for various scientific studies. Compared with this harvest of 12 deer per square mile of range per year, the average hunting kill for Mendocino County during the same period was only two deer per square mile per year. The heavier removal from the Hopland Field Station had no discernible effect on deer numbers, but fawn production and survival on the station were higher than elsewhere in the county. These records show that California deer populations can produce many more deer than are currently being taken with bucks-only hunting and very limited antlerless hunting.
Effect of limited antlered harvest on
mule deer sex and age ratios Wildlife Society Bulletin 2005, 33(2):662–668, Chad J. Bishop, Gary C. White, David J. Freddy, and Bruce E. Watkins
Abstract In response to apparent declining mule deer (Odocoileus hemionus) numbers in
Colorado during the 1990s, buck harvest limitations were identified as a possible mechanism to increase fawn:doe ratios and hence population productivity. Beginning in 1991, the Colorado Division of Wildlife (CDOW) reduced buck harvest in 4 deer management units to provide quality hunting opportunities. We examined effects of limited harvest on December ratios of bucks:100 does and fawns:100 does using data from limited and
unlimited harvest units. Annual buck harvest was reduced by 359 bucks (SE = 133) in limited harvest units as a result of limiting licenses. Fawn:doe ratios declined by 7.51 fawns:100 does (SE = 2.50), total buck:doe ratios increased by 4.52 bucks:100 does (SE = 1.40), and adult buck:doe ratios increased by 3.37 bucks:100 does (SE = 1.04) in response to limited harvest. Based on our analysis, factors other than buck harvest were
regulating population productivity, and limiting buck harvest to enhance fawn recruitment is not justified in Colorado. Limited buck harvest should be considered an issue of quality hunting opportunity rather than deer productivity.
Effect of Density Reduction on Overwinter Survival of Free-Ranging Mule Deer Fawns
Gary C. White and Richard M. Bartmann
The Journal of Wildlife Management
Vol. 62, No. 1 (Jan., 1998) (pp. 214-225)
Page Count: 12
Understanding how overwinter survival of fawns changes as a function of density of deer is a critical relation for managing mule deer (Odocoileus hemionus) populations. We examined change in overwinter survival of fawns in response to intentional density reduction by radiotracking fawns on control and treatment areas. Deer density on the treatment area was lowered about 75%, mostly from antlerless harvests in December. There were 7 years of pretreatment data, 4 years of harvest, and 3 more years of posttreatment monitoring. Fawn survival rate on the treatment area during the 3 winters after density was lowered averaged 0.16 higher (P = 0.001) than the control area. After density was lowered, body mass of fawns on the treatment area in November-December averaged 0.8 kg more than the control (P < 0.001). A parallel decline in deer density began on the control area 2 years after initiation of the intentional density reduction on the treatment area. This decline was unexpected and the cause unknown, which left unanswered what the differences in fawn survival and body size between the 2 areas might have been if the control population remained high.
Tyler State Park, If deer hunts worked, there would be fewer deer December 9, 2012 Burlington County Times
This is the 25th consecutive year that Tyler State Park officials have sanctioned the slaughter of deer. This fact demonstrates the futility of the hunt, because if it truly worked to reduce the population, the hunt would not have to be repeated year after year... Verne Smith, a professor who teaches animal law at Widener University says, "Hunting decreases the herd one year and increases it the next. It's called compensatory rebound and the DCNR knows these facts. Wildlife scientists showed that twin-fawn births were almost three times greater in hunted herds. Hunting provides the PGC with license revenues and residents with a feeling that something is being done about deer numbers...
Tyler State Park, Hunters, protesters at Tyler for annual deer hunt December 6, 2012 Pennsylvania, phillyBurbs.com
“The hunt is an exercise in futility, or as we like to call it, an execution in futility, because it has the effect of actually increasing the number of deer,” said Pearl. “It has the effect of making the deer reproduce that much faster ... The number of deer killed in the most recent hunt was not available Wednesday. Before the most recent hunt, the total was 2,577 since the hunts started in 1987. The average yearly harvest is 117....
Mentor ends deer culling efforts, plans for future program February 11, 2013 Ohio, Plain Dealer
... bow hunting on private property and sharpshooters in city parks – netting 333 animals.. ""You can never take a year off ...Once you start this program, you have to keep going because of a rebound effect where the deer will return." ... said city Parks, Recreation and Public Facilities Director Bob Martin ...
Duluth city bowhunt seems to be thinning deer herd? February 17, 2013 Minnesota, Duluth News Tribune
... city bow hunters took 574 deer in last year's city hunt, according to a final report from the Arrowhead Bowhunters Alliance, which conducts the hunt for the city... down slightly from 587 in 2011 ... [effectively a recreational hunt with a stable harvest and stable deer population] ...
Charleston, Urban deer hunt off to usual fast start September 22, 2013 West Virginia, Charleston Gazette
... bowhunters already have dragged 36 dead deer out of Charleston backyards. That's as many as were killed in the entire 2008 season, said City Manager David Molgaard... " We'll never eradicate the nuisance." ...
Jackson City Council to vote on allowing annual deer cull during council meeting this week December 17, 2013 Michigan, MLive.com
... Jackson City Council members are expected to rubberstamp the annual deer cull in Ella Sharp Park this week... Eric Terrian said in a memo to city officials the deer harvest is a result of deer population continuing to grow ... About 460 deer have been killed during the last six culls ... This will be the seventh annual deer cull ...
Great Swamp Wildlife Refuge in New Vernon to conduct deer hunt October 22, 2013 New Jersey, NJ.com
... This will be the 40th year that the refuge has held a regulated deer hunt. The purpose of the hunt is to maintain a balanced deer population ...
Deer Produce More Fawns in Response to an Urban Hunt Since the Food Supply Is Increased for the Remaining Deer
"An additional complication in urban deer management is that per capita reproduction is density-dependent, meaning that the average number of fawns produced and reared by each doe increases as the total population decreases ... " - Cost and Controversy in Managing Urban Deer, NHS Reports March-April 2000
Hunting only lowers deer numbers on a temporary basis. A study by Richter & Labisky, "Reproductive Dynamics and Disjunct White-tailed Deer Herds in Florida," in The Journal of Wildlife Management, determined that the "incidence of twinning was 38% on hunted herds and 14% on nonhunted sites."
Urban wildlife: There are humane alternatives to ineffective culls June 11, 2013 British Columbia, Vancouver Sun
... Nicholas Read, author of a book on urban wildlife ... American studies going back to 1951 have repeatedly found that with urban deer populations, per-capita
reproduction is density dependent, so as population is decreased by slaughter, the number of fawns born and reared to maturity increases in inverse proportion to cull rates. It seems that the best way to stabilize urban wildlife populations might be to allow them to find a natural balance based on what the city environment will support ...
Does Make Up For Losses Of Hunted Bucks November 28, 2000 Science Daily
... Labisky and colleagues examined the reproductive tracts of 380 legally harvested does from four areas of Florida. ... Males comprised 56 percent of the fetuses in the hunted areas but just 39 percent in the non-hunted areas, it found. As if that weren't enough, the researchers also found 38 percent of does on hunted sites carried twins, compared with just 14 percent on non-hunted sites....
Aerial deer survey results March 5, 2014 Connecticut, The Redding Pilot
... the Connecticut Agricultural Experiment Station (CAES) conducted helicopter aerial deer surveys of four square miles in February 2013 and six square miles in January 2014... Average estimated deer density pre-sharpshoot and post state-regulated hunting season on the four square miles in 2013 was just over 30 deer/square mile. Average estimated deer density on four square miles on non-deer reduction areas (two CDC sites, two non-CDC sites) in 2014 was 34 deer/square mile...
Wilton: Deer control: Hunting alone is not getting it done January 8, 2012 Connecticut, Wilton Bulletin
... Wilton's density of deer is presently about 69 deer per square mile, based on the Department of Environmental Protection's flyover count.... "If we harvest 300 a year it could take us maybe seven years.... But of course that does not include baby deer, which tend to come in twos." [Wilton's deer cull program has been in place since 2000].
Upper Makefield hires deer managment company February 6, 2013 Pennsylvania, phillyBurbs.com
... Eccologix killed 1,024 deer in Upper Makefield between 2007 and 2010 and thinned the population down to about 90 deer per square mile, said company co-owner Eric Schade. It's now climbed back up to about 125 per square mile ...
Solebury ponders action against deer February 6, 2013 Pennsylvania, phillyBurbs.com
... The township last sought to reduce the number of deer in the township in 2007, when there were about 155 deer per square mile, said Michael Kennerley, chairman of the deer committee. Afterward, the number dropped to 99 deer per square mile. Ever since, the number has been increasing, rising from 99 to 105 that following year and then ever upward until the most recent estimate of 141 deer per square mile
Buffalo: Too Many Deer Near Route 5? New York, WGRZ-TV
... Mark Kandel, a wildlife expert with the state Department of Conservation says the deer population in the area has been high for the past ten years.... Buffalo, Lackawanna and the northern part of Hamburg are closed to deer hunting. "...And have never really been open to deer hunting in the last 75 years, so the population is pretty much unchecked," ... experts have not seen a spike in numbers this year, and the warmer weather has not really impacted the habits of the deer...."The deer may be more visible because the weather conditions ... [no deer cull in this area, yet the ppopulation has been stable for 10 years, not doubling each year as some suggest will happen without an urban deer cull]
A text titled "Wildlife Ecology and Management" by William Robinson states quite clearly: "The general theory of harvesting animals is based on the premise that when animals are not harvested at all, growth and recruitment are balanced by natural mortality and that the average growth rate of a population at its carrying capacity is zero. Harvesting reduces the population size, but the reduction results in an increase in the growth rate of the population. This increase in growth rate is brought about because of higher birth rates and lower death rates resulting from decreased competition for resources. This increased growth rate provides a surplus of individuals above the number required to replace the population, and this surplus can be harvested."
Example of The Increase in Fertility Resulting From and Urban Hunt
Watchung, Fifty Deer Killed in Watchung's Hunting Season February 15, 2013 New Jersey, Patch.com
... Killing does is the primary way to control the population, [Councilman] Franklin said. Through this year's hunt, 38 fetuses were killed, he said—some had twins and one doe had triplets ... When the borough had its first deer hunt, professional hunters were hired. But now ... the borough relies on sportsmen and clubs like the Warren Blue Ridge Sportsmen [this is a effectively a recreational hunt] ...
Springbrook Prairie, Deer population program begins November 5, 2013 Illinois, Naperville Sun
...Waterfall Glen, near Darien, has had a deer management program for 22 years ...An aerial census done each winter ... Reproductive rates — which show 95 percent of the adult females taken out are pregnant with two fawns ...
Same for Mountain Lions
Study prompts Washington to revamp cougar hunting September 26, 2012 Summit County Citizens Voice
... Whether hunters killed 10 percent or 35 percent of cougars, the population remained the same... Based on the the 13-year study, the Washington Department of Fish and Wildlife is implementing a new cougar management plan based on equilibrium management. Hunters will remove no more than the surplus of animals that would be generated through natural reproduction ... the 13-year study headed by Rob Wielgus, director of WSU’s Large Carnivore Conservation Lab, has overturned that presumption...
'There is no deer crisis' September 25, 2013 Connecticut, Greenwich Time, Natalie Jarnstedt
... Hunting is the only reason for 38 percent fawn twinning/tripling in hunted herds, dropping to 14 percent in non-hunted herds according to Richter & Labisky, "Reproductive Dynamics and Disjunct White-tailed Deer Herds in Florida." ... There is no deer crisis -- numbers are down and the supposed ideal number of 10-12 deer per square mile is a bait-and-switch tactic, since only a few years ago, that magical number was 15....
Effect of Hunting on Tree Density
The Response of Tree Regeneration to Deer Management in Southwestern CT: A 5 Year Update January 4, 2013 Connecticut, E. Faison
Highstead, Redding, CT
The towns of Redding and Ridgefield CT began deer hunting on several town preserves in 2006. In 2007 Highstead established forest monitoring plots in these preserves and nearby unhunted properties to document any changes to forest understories resulting from deer management. These plots were resampled for the first time in 2012, and the results are presented here.
From 2007 to 2012, tree seedling (≥30 cm<2.5 cm diameter) density increased in both hunted and unhunted properties (Fig. 1), whereas species richness of tree seedlings (the number of different tree seedlings per plot) changed little from 2007 to 2012 in either management category. [click on image to enlarge, tree density increased more in unhunted properties]
Genetic diversity and population structure in urban white‐tailed deer JA Blanchong, AB Sorin, KT Scribner - The Journal of Wildlife Management, 2013
... We compared genetic diversity and structure among deer in 2 urban metroparks with deer in a fenced reserve and with deer from an open, continuously distributed population to inform urban deer management. If urban deer maintain species' typical matrilineal genetic structure, removal of female groups may effectively reduce local abundance. However, if gene flow in urban areas is high, dispersal may impede efforts to reduce abundance. Although genetic diversity was high and mean relatedness was near zero in all locations, distributions of pairwise relatedness in urban metroparks and the fenced reserve contained greater proportions of closely and distantly related deer than the open locations, likely attributable to matrilineal structure....
Effects of Urban Hunting Are Short-Term at Best
Lewis Morris Park struggles to restore forest habitat September 29, 2012 New Jersey, Dailyrecord.com
... the county park commission has for 16 years tried to manage through a controlled hunting program... When Lewis Morris Park initially was surveyed in 1996, there were 63.2 deer per square mile... From late August to early October 2009, they conducted eight spotlight deer surveys in Lewis Morris and adjacent land in the Washington Valley section of the township and reported nearly 65 deer per square mile... Does in Lewis Morris produce two to three babies a year ...
Stevens Point looking at new option to cut deer population November 14, 2013
... "culling" to harvest antlerless deer. City leaders said they've been doing it for about 17 years ... "We've been doing it quite regularly, we think that the number of deer is roughly the same as it was," said Elbert Rackow, Stevens Point Deer Management Committee... looking for a new way to cut down on deer in the city...
Deer Produce Fewer Fawns When Food Supply is Low: Harsh winters, habitat loss hurts Plains hunting December 30, 2011 North Dakota, Boston.com... Three brutal winters and a steady loss of habitat ... Mule deer typically produce from 0.8 to 1.2 fawns per doe, but last year that number dropped to 0.59 fawns, ... said Randy Kreil, wildlife chief of the North Dakota Game and Fish Department ... "They may be pregnant going into the winter, but they're just not able to bring the fawn to birth ... they will reabsorb the fetus and use the energy to stay alive. If you have that happen three years in a row, you really limit the amount of new animals coming into the population."
Twin Falls controls park deer population February 18, 2013 West Virginia, Wycoreport
... Park visitors reported seeing as many as 200 to 250 deer as they drove through the park during the 1980s and early 1990s. “Now, you might see 15,” said park Superintendent Scott Durham. At the time, Durham explained, the large deer herd on the park were over-browsing the food supply. As a result, he predicted then, the deer would destroy their future food supply and die from disease and parasites due to malnutrition. “That didn’t happen,” Durham said last week. “What did happen is the deer stopped reproducing.” ... response to a reduced food supply ... “We have observational evidence to support this,” emphasized Durham, who is a wildlife biologist...
Small fenced area helps to keep foliage protected February 18, 2013 Wycoreport [This is the story that appeared in the Aug. 17, 1992 issue]
... Deer exclosures, a small area fenced to keep deer from eating the inside foliage, were erected ... to show that deer are over-browsing the food supply.... The over-population is causing mass destruction to the forest and in the end will cause the demise of the deer... In the May 18 edition, Durham said, “The deer are destroying their own habitat, eating their own future food.” ...
Higher density deer population move more frequently
Effects of population reduction on home ranges of female white-tailed deer at high densities, Howard J Kilpatrick, Shelley M Spohr, Kelly K Lima Canadian Journal of Zoology, 2001, 79:(6) 949-954, 10.1139/z01-057
ABSTRACT: The relationship between deer density and home range size is important in assessing the effectiveness of deer reduction programs and predicting the effects of deer on habitat. We quantified annual home range and core area size and spatial configuration of adult female white-tailed deer (Odocoileus virginianus) exposed to a population reduction program and a control group exposed to no population reduction program over a 4-year period (19941997). Deer were removed from Bluff Point during a 9-day shotgun hunt in 1996 and a 4-day removal program in 1997. Annual home range size during high deer densities (8891 deer/km2) were larger than during periods of moderate (20 deer/km2) and low deer densities (11 deer/km2). We found a positive relationship between deer density and home range size. Annual home range size for the control group of deer did not differ among years. There were no significant shifts in the spatial arrangement of deer home ranges as deer densities were reduced. Significant improvements in deer herd health and reductions in deer browsing were documented during the 2-year deer reduction program. Population reduction programs at our study area did not cause the resident deer population to expand home range size or shift into adjacent habitat. We believe that localized deer reduction programs can be effective tools to manage problem deer herds. Deer removal efforts initiated to reduce deer damage to vegetation, particularly in urban areas, may have an added effect of reducing foraging range of the remaining resident deer. [this also indicates that non-lethal methods such as birth control can be effective since deer tend to remain in home ranges]
Does Tend to Be Territorial
Ranging behaviour of roe deer in an experimental high-density population: Are females territorial? 2012 Comptes Rendus Biologies, Marie-Line Maublanc ...
We studied the ranging behaviour and spatial relationships between seven roe deer during more than 4 years in a partly wooded 14.2-ha enclosure. The animals (three young males, four adult females) were monitored with GPS telemetry collars. As expected, the surface area and overlap of the males’ bimonthly ranges decreased, and the distance between their arithmetic centres increased, as they became adult and, for two of them, territorial. Unexpectedly, females also tended to space out, the surface area and overlap of their bimonthly ranges being minimal in May to June, i.e. during the birth period. The distance between their arithmetic centres reached its maximum at the same time. Overlap between females’ ranges was consistently lower than those between males and females’ ranges, or between 1-year old males’ ranges. Our results raise the questions of female seasonal territoriality and of independence of the spacing systems of the two sexes in roe deer.
What about introducing a predator? Allowing hunters to cull an urban environment is just a way of reintroducing a predator to control the population. Some have even suggested encouraging wolves or coyotes to control the deer population. A study by Scotte E. Henke summarizing the literature of the Effects of Coyote Control on Their Prey (2010) concludes: " Although white-tailed deer and bobwhite quail reproductive success increased with coyote removal, overall population densities for both species remained unchanged. This implies that a compensatory mortality mechanism is involved with these populations and that potential population increases of certain game species due to coyote removal are short-lived. All studies indicated that coyote control caused an immigration of coyotes into the removal areas. Coyote population densities returned to pre-removal levels typically within 3 months after removal efforts ceased."
Therefore, short-term coyote removal programs typically are not sufficient in reducing coyote density and, therefore do not alter ecosystem composition. However, intensive, long-term coyote removal has been successful in reducing coyote populations by over 40%, which has resulted in prey-base increases.
New Research of Food Availability and Reproduction
Risk‐sensitive allocation in seasonal dynamics of fat and protein reserves in a long‐lived mammal KL Monteith, TR Stephenson, VC Bleich, MM Conner… - Journal of Animal Ecology, 2013
... Our goal was to reveal the linkages between nutrition and life-history traits to understand how long-lived, iteroparous organisms balance the allocation of somatic reserves to reproduction, while retaining reserves as insurance for survival in unpredictable environments... Female deer mostly synthesized lean body tissue over summer and committed post-winter fat reserves to reproduction relative to their availability above an autumn threshold (>8·6% IFBFat), which was lowered by 2·8 percentage points (pp) for each additional young recruited. Mothers reduced their autumn fat threshold to secure current reproductive investment and, thereby, endured a cost of reproduction at the expense of fat accumulation... Consequently, behaviour and life-history strategies may be as much a function of nutritional contributions of the previous season as of the current one.
Hamilton, Deer population drops at Iroquoia Heights October 21, 2013 Canada, Jamilton spectator
... an aerial survey at the Ancaster park in February spotted 58 deer, down considerably from 2009, when 102 were counted ... Liz White, director of the Animal Alliance of Canada and a member of an advisory committee that recommended holding off on a hunt at Iroquoia Heights, said ... "In every town that I've been involved with where they've actually culled deer, the numbers have essentially remained about the same because new deer come in ... "But in circumstances where you just remove the feed, it doesn't support the numbers in that kind of density. I suspect that's true in Iroquoia Heights, too."