The report below was produced by the Center for Animal Protection
White-Tailed Deer - An Ecological Perspective
- O.J. Schmitz, A.R.E. Sinclair. The Science of Overabundance, Smithsonian Institution Press. 1997.
State, county and local Habitat enhancement
Sweeping ecological indictments that white-tailed deer are permanently destroying local forest understory are often unaccompanied by baseline data, inventories and, where appropriate, acknowledgement of local and state game management programs, habitat enhancement and private fee-hunting operations.
Deer management has become politicized and fraught with hyperbole: agencies allied with state game departments practicing single-species management neglect to address, in any substantive or public way, management's impact on biodiversity and, quite literally, forcing or maintaining higher rates of deer reproduction. In the United States, habitat enhancement is conducted as a matter of policy on federal, state and county lands.
During the 1970s, the Journal of Wildlife Management reported: "Deer herds are being managed with ever increasing intensity. The primary management plan has been one directed at increasing the productivity of the white-tailed deer through habitat manipulation and harvest regulation . . .to produce optimum sustained deer yields and . . . maximum hunter satisfaction."
New York's regional wildlife manager boasted: "We shall attempt to raise the number of deer until we experience high incidents of deer-car collisions, depredation of agricultural crops becomes intolerable and the effects of deer habitat results in deterioration . . . to increase the success rate of big game hunters."
Managing deer for increase: mowing, preferred crops, clear-cutting - and hunting
For density-dependent species like white-tailed deer, hunting and associated habitat management thwart natural coping mechanisms at every turn. State wildlife departments clear-cut forests and plant deer-preferred crops and vegetation to create surplus food for deer; substantial enhancement occurs under cooperative agreements among the Division of Fish and Wildlife, the Division of Parks and Forestry and private landowners. For example, the Division maintains a cooperative clear-cut agreement with the Bureau of Forestry at Wanaque Wildlife Management Area (WMA) in the Highlands. The program "benefits" primarily "deer and turkey." More prosaic and more common forms of enhancement - mowing, planting deer-preferred crops, maximize doe fecundity: well-fed does breed earlier and bear more fawns. Hunting elicits the same effect, creating more food by removing competitors, sometimes doubling reproductive rates, or keeping rates high. Studies show that in the absence of hunting, fertility declines.
In fact, hunting itself is the primary tool for keeping deer numbers high. Hunting not only increases reproductive rates in poor habitat, but prevents populations in optimum habitat from reaching a plateau where fertility actually declines. "Rates of reproduction and rates of mortality or emigration will reach a balance, so that the net rate of increase becomes zero and the population numbers stabilize at some equilibrium level -- within such populations, hunting acts to reduce numbers . In so doing, it brings the population once more below the level at which it is limited by environmental resources, effectively releasing the density-dependent brake on population growth. Reproduction increases, juvenile mortality falls, and the whole population age structure shifts towards young animals . . .productivity of the population rises."
And: "The increased reproductively of a population under exploitation [hunting] is now well-documented (e.g. Wact, 1955; Silliman and Gutsell, 1958; Gulland, 1062; and see also Eltringham, 1984.) In our discussions of management for control or exploitation, we have repeatedly stressed that most natural populations respond to reduction in numbers by increased productivity."
Reaching capacity; fertility rates decline in absence of hunting.
In contrast, non-hunted areas repeatedly show declines in hunting: "In western areas of the state [New York] a 1.60 fawn/doe ratio existed in 1939-43. Following antlerless [male/female] seasons, the reproductive rate increased to 1.90 embryos per doe in 1947-49. In areas where no antlerless seasons were held and the population density remained unchanged, fertility declined."
And, declining birth rates do not necessarily connote increased "starvation" or habitat "destruction." Differences in deer reproductive rates have long existed within the state of New Jersey, and do not result in starvation or destruction of habitat. Deer in southern New Jersey reached carrying capacity and reduced fertility in 1935. In fact, birth rates in urbanized areas decline:
Early studies in New Jersey indicated that differences existed in the reproduction rate of deer (Sweet and Wright 1953). Deer herds in some areas of the south reached the carrying capacity of the range as early as 1935, whereas North Jersey experienced its peak later in the 1950s (hoard 1972). Data collected in the 1950s showed that northern adult does had an average reproduce rate of 1.90 [under hunting] whereas southern adult does averaged 1.57 embryos (Mangold 1959) . . . at the present time [1978] differences still exist between areas of the state.
Biological impacts of crop planting, clear-cutting, mowing
When promoting clear-cutting, Minnesota's DNR states that "habitat has a major influence on deer reproduction," which is in large part determined by food supply: "At high densities, deer may not be bred until the 2nd or 3rd estrus." Clear-cutting fast-forwards breeding: "The reproductive performance of does is primarily determined by the nutritional value of food . . . as well as age. . . As density of does increases the reproductive rate declines since there is relatively less food available per deer. Theoretically, the reproductive rate of deer would drop to zero if deer ever reached 100% of summer carrying capacity."
Under the "New Jersey Statewide Development Project, the Division of Fish and Wildlife uses federal game restoration funds (see Pittman-Robertson Act) for "game" propagation:
New Jersey Statewide Development Project: To manage habitat on State lands so as to maximize wildlife populations, to develop and maintain facilities and lands for public users; and to provide public access to wildlife resources.
Most local governments are unaware that biologically unnatural levels of hunted species are produced at state Wildlife Management Areas (WMAs), and on local, leased or owned hunting club acreage, throughout the state:
Habitat development and maintenance to benefit deer are conducted on 73 state owned Fish and Wildlife Management Areas totaling over 192,000 acres.
Habitat management is encouraged on other public and private lands. Limited burning, wood harvest and planting of various agricultural crops favored by deer can increase the carrying capacity by increasing the quality and quantity of food available.
The U.S. Fish and Wildlife Service admits that these practices effect "significant acreage" required and used by non-game species. Between 1975 and 1985, the last year for which specific manipulation statistics were released, 6 million acres were burned; 517,754 acres chemically defoliated; 4 million acres planted and seeded; 1.8 million acres clear-cut and bull-dozed,, 264,000 acres harvested for timber -- mainly for deer. "The majority of acreage burned," wrote Interior, "impacted deer." The seeding and planting "increase[d] supply of forage for deer. . ." And the clear-cut forests, impacting forest-interior species? "Seventy-two percent of the areas harvested benefited deer." Deer benefits included acreage managed for "small game." During those years alone, states spent $949 million to increase numbers of hunted animals, especially deer. The Service no longer releases specific acres "improved."
In New Jersey, state and county parks lease lands for preferred crop planting, and are directly responsible for local population numbers. Working with the Division, the parks then "recommend" sport hunting, which will increase or maintain fecundity, as the only viable "solution." At Monmouth Battlefield and now at nine sites at six county parks, officials site tenant farmers planting deer preferred crops as requiring "relief." Absent even cursory review of state, county, local and private habitat enhancement or sport hunting or poaching activities impacting local populations, annual local sport hunts are established, creating long-term negative impacts, raising reproduction rates, and forcing deer to seek refuge in surrounding suburban areas.
White-tailed deer and Canada geese responding to production programs overflow into surrounding areas. Similarly, the Division continues to aggressively re-stock wild turkeys as farmer and suburban complaints rise. Richly, the state-stocked turkey is cited as a species which must be "controlled" - by hunting.
Increasing white-tail numbers has been the overarching goal of both the Division of Fish and Wildlife and the New Jersey Fish and Game Council:
Habitat development and maintenance to benefit deer are conducted on 73 state-owned Fish and Wildlife management areas totaling over 192,000 acres.
Habitat Management is encouraged on other public and private lands. Limited burning, Wood harvest and planting of various agricultural crops favored by deer can increase the carrying capacity by increasing the quality and quantity of food available.
In addition, killing does only changes the age structure of affected populations and increases doe/fawn ratios. Killing does is not an effective means of "limiting" real reproductive rates.
According to Illinois game department biologists monitoring severe "reduction" kills within the DuPage County Forest Preserve District: "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.
Similarly, deer reproduction increases as managers begin removing deer, thus requiring managers to work ever harder to reduce the deer population to offset the population's increasing reproductive effort. . . Finally, as if the problems caused by density dependence weren't bad enough, the effort and cost required to cull an individual deer probably increases exponentially as population density declines. Therefore, the need to work ever harder, coupled with the fact that cost increases rapidly as deer density declines, may determine the real-world limits to maintaining deer at reduced population levels.
A pivotal question energetically ignored by parks commissions remains: What other private and public acreage is in any way enhanced for deer, by the State, county, or private hunting clubs, which also plant and mow? Commissions marketing hunts fail to ascertain the extent of these programs or acknowledge the cumulative effect of decades of aggressive management on local deer. Have any local hunting interests been asked to cease their activities? Credible, comprehensive data should be compiled and publicly discussed before calling for Draconian kills that will do nothing to depress fertility rates.
Private enhancement activities are common. The Division advises hunters how to clear-cut for deer. (See, "Clear-Cutting Forests: Good or Bad for Deer in New Jersey?" Fish and Wildlife Digest," 1991-92.) Like management occurs on lands leased by hunting clubs throughout the state, in conjunction with hunting quotas that increase births.
Groups politically allied with state game agencies are equally culpable. The New Jersey Conservation Foundation, calling for widescale hunting of deer instead of statewide reform of game management practices and habitat modification, recently supported the Division's controversial deer/quail clear-cut at Buckshutem. Initially promoted solely as a means to increase deer and quail, Buckshutem metamorphosed an effort to recreate savanna for non-game species.
USDA's South Jersey Research, Conservation and Development Council urges farmers to create more deer by burning and clear-cutting to attract hunters who will lease the land at $50 --$250 per person -- as farmers complain of too many deer. At hearings in Trenton, the Farm Bureau, vociferously lobbying for deer eradications, firmly endorses this policy.
Moreover, private farmers baiting deer for private hunting or fee operations perform a disservice for neighboring farmers. As reported in The New York Times:
Some critics says that notwithstanding the intentions of Dr. Alt and his counterparts elsewhere, many practices by state game agencies and private landowners could still increase deer numbers despite the shift in killing.
For example, some opponents of hunting say, Pennsylvania and other states often using millions of dollars in federal money collected through firearms taxes -raise forests' carrying capacity for deer by clearing patches in the woods and cultivating food plants like clover. (continued on page 2)
