As female deer wander, fatal disease goes with them, Futurity, June 30, 2016“Dispersal of female deer is density dependent, meaning that higher deer densities lead to greater dispersal rates,” says Duane Diefenbach, adjunct professor of wildlife ecology at Penn State. “Therefore, reducing deer density will reduce female dispersal rates—and likely will reduce disease spread.
Female deer disperse farther than males, present disease-control challenge, Science Daily, June 28, 2016“Dispersal of female deer is density dependent, meaning that higher deer densities lead to greater dispersal rates.” He explained. “Therefore, reducing deer density will reduce female dispersal rates — and likely will reduce disease spread. Containing the spread of chronic wasting disease is going to be difficult when female deer disperse. Although not as many females disperse — 8 to 24 percent of females versus 50 to 75 percent of males — there end up being more of them, because they live longer than males and they disperse an average of 11 miles compared to 5 miles for males.”
Deer and the Vacuum Effect Fable, Local in Ann Arbor, March 8, 2015The “vacuum effect” is based on an assumption that deer behave as gas molecules do. Supposedly, if a vacancy is created in one area, deer will somehow sense that and there will be a massive flow of deer into the opened-up area. Soon we’ll be back to the same numbers as before.
Many studies have shown that deer don’t behave this way. Instead, deer favor a home range. They mostly migrate into new areas only because they have exhausted the food in their home range. In other words, if they have exceeded the carrying capacity of their current range, they may migrate. But this is not caused by a vacuum created by the removal of other deer.
Deer As Gas Molecules, Utah State University Extension, 2014 To the chagrin of the skeptics, deer from the surrounding areas did not behave like gas molecules. The wager lost and the beer dutifully handed over, the next question why didn’t the deer fill the vacuum?”
The biologists concluded that deer outside the removal area were simply too strongly attached to their own home range to be drawn to the vacancies nearby. Deer do not behave like “gas molecules.” Genetic analyses suggest that each summer range is shared by a group of related individuals, probably the daughters, granddaughters and great-granddaughters of a single female.
Deer from adjacent areas did not move into the area over a 10-year period.
Deer Management, Vassar Farms website, Vassar Farm and Ecological Preserve, Poughkeepsie, NYQ. If we lower the population density of deer on the VFEP won’t more deer move in from other areas?
A. Female deer have a small home range of less than 1 square mile. Male deer have a slightly larger territory. Some yearling bucks may move onto the land from adjacent areas in search of new territories.
Landscape structure influences space use by white-tailed deer, Amy C. Dechen Quinn , David M. Williams , William F. Porter, Journal of Mammology, published online: 16 April 2013White-tailed deer in the contiguous forest of the northeastern United States occupy large annual home ranges (>3.0 km2) that encompass average seasonal migrations between summer and wintering areas (Smith 2009; Tierson et al. 1985). Conversely, deer in highly fragmented, suburban and exurban environments occupy annual home-range areas of <0.50 km2 (Porter et al. 2004; Storm et al. 2007). In this way, white-tailed deer appear to adjust space use across a wide geographic range based on the composition and spatial structure of important resources within the local landscape.
Genetic diversity and population structure in urban white-tailed deer, ABSTRACT only, The Journal of Wildlife Management, May 2013Habitat fragmentation in urban areas has left many species isolated and vulnerable to loss of genetic variation. White-tailed deer, however, thrive in urban areas. 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. Deer from the metroparks (approx. 65 km apart) were moderately differentiated (Fst = 0.092) indicating gene flow in urban areas may be less than in other landscapes. Our results indicate that removal of matrilineal groups may reduce local urban deer abundance without inducing immigration from surrounding areas.
SURVIVAL RATES OF FEMALE WHITE-TAILED DEER ON AN INDUSTRIAL FOREST FOLLOWING A DECLINE IN POPULATION DENSITY, Proceedings of the 18th Central Hardwoods Forest Conference GTR-NRS-P-117, 2012 Our results support previous work suggesting that adult survival rates in ungulates are robust to changes in population density and indicate that density-dependent mechanisms were not acting upon adult survival in this population during our study.
Factors affecting space use overlap by white-tailed deer in an urban landscape, International Journal of Geographical Information Science, March 2011Variation in the size and overlap of space use by white-tailed deer has broad implications for managing deer–human conflicts and disease spread and transmission in urban landscapes. Understanding which factors affect overlap of home range by various segments (i.e., age, sex) of an urban deer population has implications to direct contact between deer on disease epidemiology.
We documented an increase in space use by both sexes during nocturnal hours indicating deer that shed CWD infectious material may contaminate the residential or open habitats that deer typically do not occupy during the day
ESF’s William Porter, a genuine trailblazer in wildlife research, gets new job at Michigan State, Syracuse.com, June 28, 2010You’ve been involved in so many studies with different animals. Talk about a couple involving deer that had a major impact.
One of my students, Nancy Mathews, who’s now a professor at the University of Wisconsin, studied that deer populations scattered across landscapes are really composed of matriarchal groups of females, with the oldest being the mother or aunt of every other female. That group is fixed to the landscape. They may migrate, but they always stay where they were born. This had tremendous implications for management. If you go and remove all the females in a particular area (they group in numbers of about 15), you can create a vacancy on a landscape. The previous method was to try and go into a whole community, say a park, and try to eliminate every deer across the whole landscape. That’s a political hot potato and extremely difficult. What Mathews showed is that if you have one particular problem area — say around the visitor’s center — you just have to take out about 15 does. (The males go wherever the does are).
Test of Localized Management for Reducing Deer Browsing in Forest Regeneration Areas, Journal of Wildlife Management, 2010 Home range shifts of adjacent deer coupled with the large number of animals collected in the second removal suggests that localized management only produces temporary voids within high-density deer herds. Localized management may not effectively reduce negative impacts of deer in areas of high deer density.
Evaluation of Shifts in White-Tailed Deer Winter Yards in the Adirondack Region of New York , The Journal of Wildlife Management, Feb., 2008
Jeremy E. Hurst and William F. PorterOur study suggests that low-density residential areas in lowland conifer forests may provide an energetic advantage for deer during winter due to the assemblage of quality habitat interspersed with open areas and a variety of potential food sources in environments where movement is typically constrained by deep snow. Managers should consider the potential for changes in use of deer wintering areas prior to land conservation efforts and may need to adapt management strategies to reduce conflicts in communities occupied by deer during winter.
Sharpshooting suburban white-tailed deer reduces deer–vehicle collisions, Digital Commons@University of Nebraska – Lincoln, 2008, Anthony J. DeNicola, Scott C. WilliamsToo many deer–vehicle collisions (DVCs) are one of the primary reasons local governments implement lethal deer management programs. However, there are limited data to demonstrate that a reduction in deer densities will result in a decline in DVCs. We conducted sharpshooting programs in 3 suburban communities to reduce deer numbers and to address rising DVCs. Annual or periodic population estimates were conducted using both helicopter snow counts and aerial infrared counts to assess population trends. Management efforts were conducted from 3 to 7 years. Local deer herds were reduced by 54%, 72%, and 76%, with resulting reductions in DVCs of 49%, 75%, and 78%, respectively. These projects clearly demonstrate that a reduction in local deer densities using lethal methods can significantly reduce DVCs.
Demographics of nonhunted white-tailed deer populations in suburban areas, DENICOLA, et sl. Human–Wildlife Conflicts 2(1):, Spring 2008 The results from these harvest programs indicate that sex and age structure of nonhunted deer populations are fairly uniform and predictable. There were consistently 60% females and 40% males in these environments. Also, these deer populations were comprised of ~40% yearling and adult females, ~20% yearling and adult males, and ~40% fawn
Movement patterns of rural and suburban white-tailed deer in Massachusetts, CHRISTOPHER R. GAUCilHAN, STEPHEN DESTEFANO, Urban Economics, 2005 We found the marked deer using suburban developments in NW Massachusetts in our study were non-migratory and maintained small ranges within or on the edges of human habitation
Does are from Venus, Bucks are from Mars, Montana Outdoors, Nov-Dec 2005 The matriarch (mule deer) continues to give the brush-off to her yearling daughter for most of the summer. The young doe survives, however, because her mother had schooled her during the previous summer on how to find nutritious food, hiding cover, and shelter from harsh weather. The yearling daughter usually decides it’s convenient to establish a home range that generally overlaps that of her mother’s. It’s kind of like living across the street from Mom.
If for some reason the yearling daughter tries to set up housekeeping in a totally different area, she usually wanders into the birthing territory of other matriarchs in the population and subsequently is shooed off by them. That forces her to return to familiar turf and her mother’s apron strings.
After summer, the matriarch allows her yearling daughter, and any older daughters that may also have fawns, to rejoin her and her newborn. They form a rather formidable group of females. Sometimes, these matrilineal groups comprise three or more generations.
MOVEMENT BEHAVIOR, DISPERSAL, AND THE POTENTIAL FOR LOCALIZED MANAGEMENT OF DEER IN A SUBURBAN ENVIRONMENT, Abstract from Journal of Wildlife Management, 2004
WILLIAM F. PORTER, H. BRIAN UNDERWOOD, JENNIFER L. WOODARDWe examined the potential for localized management of white-tailed deer (Odocoileus virginianus) to be successful by measuring movements, testing site fidelity, and modeling the effects of dispersal. Fifty-nine females were radiomarked and tracked during 1997 through 2000 in Irondequoit, New York, USA, a suburb of Rochester.
Deer showed strong fidelity to both summer and winter home ranges, and 30 of 31 females showed overlap of summer and winter home ranges. Annual survival was 64%; the major cause of mortality was deer–automobile collisions. Average annual dispersal rates were <15% for yearlings and adults. Using matrix population modeling, we explored the role of female dispersal in sustaining different management objectives in adjacent locales of approximately 1,000 ha. Modeling showed that if female dispersal was 8%, culling would have to reduce annual survival to 58% to maintain a population just under ecological carrying capacity and reduce survival to 42% to keep the population at one-half carrying capacity. With the same dispersal, contraception would need to be effective in 32% of females if the population is near carrying capacity and 68% if the population is at one-half of carrying capacity.
Localized Management of White-Tailed Deer in the Central Adirondack Mountains, New York, Anne M. Oyer and William F. Porter, The Journal of Wildlife Management, Vol. 68, No. 2 (Apr., 2004), pp. 257-265We tested whether localized removal of a social group created a persistent area of lower deer density on Huntington Wildlife Forest (HWF) in New York, USA. We examined relative abundance and home ranges of deer to determine whether the removal created a lower-density area, how long the lower-density area persisted, and origin of repopulating females. Abundance declined due to removal. Home-range analysis showed that no radiomarked deer from surrounding areas moved into the removal area post-removal and that deer density was reduced for 5 years.
Review of the Ecological Effects and Management of White-tailed Deer in New Jersey, The Nature Conservancy, 2004The social structure and territoriality of deer herds make it possible to use hunting programs to manage deer populations within a given locality (Jones et al. 1997, McNulty et al. 1997). For a hunting program to be effective in controlling the deer population within a given area, a preponderance of does rather than bucks must be taken because of the strong territorial disposition of matriarchal deer herds and the wide-ranging nature of bucks (McNulty et al.1997). A reduction of females within a given locality will result in the creation of a spatial void of deer with in that locality because does have a very strong tendency to remain within their established territories and do not emigrate to other areas, even if they are vacant (Jones et al. 1997, McNulty et al. 1997). The persistence of a hunting-induced spatial void is a function of local deer population densities and habitat quality, but it can remain in effect forup to two years (McNulty et al. 1997).
Localized Management for Reducing White-Tailed Deer Populations, Stacy A. McNulty, et al, Wildlife Society Bulletin, Vol. 25, No. 2, Deer Overabundance (Summer, 1997), pp. 264-271We documented the summer home ranges of 8 social groups of females at Huntington Wildlife Forest, in Newcomb, New York. We removed 14 members of 1 social group (the target group) in 1994 and monitored movements of deer in adjacent social groups with radiotelemetry from 1994 to 1996 to determine the response to removal. Removal of the target-group deer created a low-density area of about 1.4 km2. After removal, no deer in the adjacent area moved its home range significantly closer to the removal area, despite the reduction in population density.
Efficacy of localized management for reducing deer herbivory of forest regeneration areas, Warnell School of Forestry and Natural Resources, 2004?As of October 2004, none of the 72 remaining radio-collared females have shifted their home range to include the removal area. We will continue to collect telemetric data until November 2004 to document any movements of radio-collared animals into the removal area. If the results of our study indicate that localized management reduces damage to forest regeneration to acceptable levels over the long-term (= 5 years), then forest and wildlife managers could inexpensively ensure regeneration success, sustain forest structure and composition, and maintain forest biodiversity.
Feasibility of localized management to control white-tailed deer in forest regeneration area, Campbell, et al, APHIS, Wildlife Society Bulletin, 2004, 32(4): 1124-1131Female deer displayed high fidelity; on our study site, they met the a priori assumptions of localized management.
Survival and Movements of White-Tailed Deer in Suburban Chicago, Illinois [abstract], Journal of Wildlife Management, April 2002Management of high-density suburban deer populations requires knowledge of survival and movement to predict population trends. However, natural and human-induced influences on survival and movement of suburban deer are poorly understood. Therefore, we marked 208 (60 bucks, 148 does) white-tailed deer (Odocoileus virginianus) from forest preserves in Chicago, Illinois, USA (1994-1998). Seasonal and annual survivorship was >0.80 for 114 does and 13 bucks. Deer-auto collisions produced the highest mortality rates, 0.10 (95% CI 0.06 to 0.14) and 0.17 (95% CI 0.0 to 0.37). Spring dispersal for does was 7% (3 of 41) for fawns and 6% (5 of 83) for yearlings and adults; and for bucks it was 50% (8 of 16) for fawns and 7% (2 of 30) for yearlings and adults. All dispersals were <9 km, except for 1 parous doe that moved 33.9 km. Doe home ranges averaged 51 (95% CI 40.5 to 61.5), 26 (95% CI 22.0 to 30.0), and 32 (95% CI 19.6 to 44.4) ha for winter-spring, summer, and fall, respectively. A priori, was developed a set of 10 logistic regression models for suburban doe survival relative to home range size and traffic exposure indices. Using Akaike's Information Criterion (AIC), the best models included covariates reflecting home range size and traffic exposure. Inference across a ≥90% confidence set of survival models indicated substantial spatial heterogeneity in mortality risk for suburban does. High survival and philopatry by suburban deer apparently contribute to their overabundance in metropolitan areas.
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, 2001Population 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.
White-tailed Deer Studies in Northeastern Minnesota, International Wolf Center, 2000?The doe population in Northeast Minnesota produces an average of 1.6 fawns per doe. All fawns spend their first year with their mothers but after that, sons strike out on their own while most daughters remain with their mothers. During the fall, bucks roam an average distance of 2 miles from the center of their home range searching for does.
About 80% of does use their mothers’ home range for their entire lives. Sixty percent of bucks, however, establish new summer ranges when they are 1 year old. Yet, 95% of new home ranges are never farther than 24 miles from birth sites. Genetic studies revealed that deer in the study area are the descendants of eleven different deer lineage’s
Variation of white-tailed deer home ranges in fragmented urban habitats around Chicago, Illinois, University of Nebraska – Lincoln DigitalCommons@University of Nebraska – Lincoln Wildlife Damage Management Conferences, 2000Home ranges of does around Chicago are among the smallest reported for whitetails throughout their range. Past studies have reported that home range sizes of deer increase with population decrease. Our observations suggest that home range area may expand when deer densities exceed ecosystem carrying capacity. Thus, it may be especially important to control deer densities in urban areas to preserve local plant communities and to minimize deer/human conflicts.
Sociospatial Dynamics of White-Tailed Deer in the Central Adirondack Mountains, New York, [Abstract], Journal of Mammalogy, May, 1997
Jocelyn L. Aycrigg and William F. PorterFemales in our study population exhibited a high level of philopatry to summer ranges inhabited by their kin group (<3% of females dispersed from their natal area). The use of winter ranges was more variable. Movements of individuals on summer range did vary with age: females >5 years old maintained home ranges in spring and summer that were more exclusive than those of younger females. Pregnant females used smaller areas during spring than barren females.
HOME RANGES AND HABITAT SELECTION OF WHITETAILED DEER IN A SUBURBAN NATURE AREA IN EASTERN NEBRASKA, SCOTT E. HYGNSTROM and KURT C. VERCAUTEREN, University of NebraskaDeer response to hunter activity was highly variable. Most deer maintained relatively static home ranges before, during, and after the hunting seasons, but three deer moved over 2,000 m and established non-overlapping home ranges after the hunting seasons. Since no migration patterns were observed, we suggest that regulated hunting seasons continue in both the upland and lowland areas of GPFF, and in the open space areas of Bellevue where conditions are conducive to hunting.
With white-tailed deer populations still growing and invading settled areas, all sorts of people are learning firsthand about the big mammals’ behavior, National Wildlife Federation, Oct 1994Part of the whitetail’s success is due to its prodigious fecundity. Does breed as early as 6 months in some areas, and at 18 months in others, then bear young every year and frequently give birth to twins and triplets. Over the course of an average 10-year lifespan, a single doe and her offspring might produce 100 fawns. In summer or home ranges in northern climes. Ozoga found that the female offspring of dominant does usually claim birthing areas near their mothers, which in turn tend to claim the same birthing areas they claimed the year before. The mother and female-offspring territories overlap slightly; third-generation andother related females move farther out.
The frustration for motorists is that deer react to cars in seemingly illogical ways, especially at night, often waiting until a car is quite close and then running out in front of the vehicle just in time to get hit.
The Rose Petal Theory: Implications for Localized Deer Management, FISH AND WILDLIFE SERVICE No. 59, 1992Because of high female philopatry and low dispersal rates, the ideal management action would be to remove an entire family unit. The number of deer that need to be removed clearly depends on the size of the family. In practice it is not feasible to know the exact size or composition of the family group. However, continuous removal from a localized area will ultimately eliminate all family members from one or more groups. Became dispersal is low and philopatry is high, deer will not rapidly diffuse back into the area as traditionally believed.
Social organization in deer: Implications for localized management, Environmental Management Nov/Dec 1991,
William F. Porter, Nancy E. Mathews, H. Brian Underwood, Richard W. SageJr., Donald F. BehrendTraditional modes of hunting to control populations are inappropriate in many of these areas because of intense human development and activity. This article explores an alternative approach for population reduction based on deer social organization. Female white-tailed deer are highly philopatric and female offspring remain near their dams for life. This suggests that a population expands slowly as a series of overlapping home ranges in a form analogous to the petals on a rose. Incorporating the rose petal concept into a model of population growth shows that removal of deer by family unit can potentially alleviate conflicts in localized areas for as many as 10–15 yr.