Deer Population Density Research Articles

ЧИСЛЕННОСТЬ СИБИРСКОЙ КОСУЛИ (CAPREOLUS PYGARGUS PALL., 1771) В ЦЕНТРАЛЬНОЙ ЯКУТИИ

Data on the population size, density and spatial pattern of Siberian roe deer in Central Yakutia are given, including the chronology of population cycles since 1960s. Central Yakutia is the northernmost periphery of the species area in North-Eastern Asia. More than 5 thousand individuals were counted there in 1963, but the number of roe deer was reduced to only 0.8 thousand by the early 1970s. This dramatic decline resulted from: 1) unfavorable wintering conditions through several sequential years and 2) poaching. Roe deer was included into the Red Book of Yakutia with the status of a ‘rare species with restricted area’. Decrease of the Central-Yakutian roe deer population coincided with the general trend of the species decline in the most territories over Russia. In the early 1990s, the population of roe deer in Central Yakutia began to restore rapidly, and soon exceeded the number from the late 1960s. In 2002 the species was excluded from Yakutian Red Book. By the data of aerial count in 2009, Central Yakutia has roe deer population of about 10 thousand individuals. Most of animals inhabit the Lena-Amga interstream area, lesser part of population occupies the Lena-Vilyui interfluve.

Habitat-population density relationship for the white-tailed deer Odocoileus virginianus during the dry season in a Pacific Mexican tropical dry forest

The habitat-population density relationship in the white-tailed deer Odocoileus virginianus was analyzed in a tropical dry forest of the Zicuirán-Infiernillo Biosphere Reserve in the Pacific region of Mexico. In 2008, pellet groups were sampled in strip-transects during the dry season to estimate population density in five locations. Habitat variables (physical, vegetation, and human) were obtained during field sampling and through the use of geographic information systems. Principal component analysis and stepwise multiple regression were used to analyze the habitat-density relationships. The mean population density of white-tailed deer for the region was 6.7 ind/km 2 ; however, this varied significantly among sites (1.9–11.3 ind/km 2 ). Higher densities were found in sites with lower human activity, irregular topography, dense understory cover, and well-developed tree strata. In contrast, sites with lower deer density presented high human activities such as livestock and crop production, which act to modify the tropical dry forest. We discuss the management and conservation implications.

Monitoring Red Deer and Roe Deer Population Density in Yedigoller-Yesiloz Wildlife Reserves in Turkey

Monitoring Red Deer and Roe Deer Population Density in Yedigoller-Yesiloz Wildlife Reserves in Turkey

Relationships between wild ungulates density and crop damage in Hungary

Game damage to agriculture represents one of the most important and most frequent human–wildlife conflicts worldwide. In Hungary and in the other European countries, damage caused by wild boar (Sus scrofa) and red deer (Cervus elaphus) is the most significant. The volume of damage is correlated with the population density of the game species, however, not exclusively. Since the growing expansion of wild ungulates is a general tendency in Europe, increasing conflicts can be envisaged. The objective of our study was to assess the possible relationships between the amount of agricultural game damage and big game population density considering some other factors (e.g. habitat structure, sown area of cultivated plants) by analysing wildlife management and land-use statistics for the 19 counties of Hungary from 1997 to 2008. According to the results, crop damage positively correlated with the population density of red deer and wild boar, with the length of forest edge, and the proportion of the sown area of maize. According to the regression model, these factors could be accountable for 74.2 % of the total agricultural game damage.

MANDIBULAR OSTEOMYELITIS IN RED DEER (CERVUS ELAPHUS HISPANICUS) AND FALLOW DEER (DAMA DAMA): OCCURRENCE AND ASSOCIATED FACTORS IN FREE-LIVING POPULATIONS IN SOUTHERN SPAIN

The prevalence of mandibular osteomyelitis, which results in a condition called lumpy jaw, and factors associated with its occurrence were investigated in syntopic free-living populations of red deer (Cervus elaphus hispanicus) and fallow deer (Dama dama) in Spain. The study material consisted of 3,586 mandibles from 2,548 red deer and 1,038 fallow deer shot during sport hunting, herd management culls, and programs for population control between 1988 and 1997 (period 1) and 2002 and 2009 (period 2) in eastern Sierra Morena, southern Spain. Disease prevalence ranged from 0.36% to 10.91% among age groups. Older animals were significantly more likely to be affected than younger ones. Red deer stags had higher prevalence than other groups. There was a significantly higher prevalence in period 1, probably associated with differences in climatic and population conditions. High population densities of female red deer contributed significantly to occurrence of disease. Intensive herd management and poor environmental conditions were considered risk factors that increased susceptibility to disease. The study of this affliction could be useful for monitoring general herd welfare and ecologic changes in Mediterranean ecosystems.

Road bias for deer density estimates at 2 national parks in Maryland

AbstractEstimating the population density of deer is an essential task for public agencies that plan a herd reduction. Distance sampling has been increasingly utilized to estimate population density, and is used by the National Park Service to estimate white‐tailed deer (Odocoileus virginianus) densities throughout the eastern United States. Many of these surveys are conducted along public roads due to limited resources and accessibility, which may violate a critical assumption of distance sampling and potentially introduce sampling bias. We used infrared cameras to confirm deer activity with respect to survey roads at 2 national parks in Maryland, USA (Catoctin National Park and Antietam National Historic Battlefield), during 2005 and 2006 and compared results with the predicted distributions. The number of deer observed during road surveys declined with distance intervals at Catoctin, but there was a similar amount of deer activity at each distance interval. At Antietam, survey observations maintained a constant level of activity beyond 200 m from the survey route, while deer activity was inconsistent between distance intervals. The mean number of deer photographs/day/sample point did vary significantly across distance intervals from the survey route at Antietam, but not at Catoctin. In Antietam, the uneven distribution of agricultural fields and public roads were significant predictors of deer activity detected during the camera surveys. At Catoctin, the fit of the detection function was improved by expanding the first distance interval. Although density estimation using DISTANCE can account for most sources of error introduced by use of public roads, our data indicate bias is likely to occur in landscapes with high road densities and long sight distances. © 2011 The Wildlife Society.

Comparison of Pellet-Group Counting Methods to Estimate Population Density of White-Tailed Deer in a Mexican Tropical Dry Forest

Wildlife species population density estimation is important from both ecological and management perspectives. The pellet-group counting method has been used to evaluate density of the white-tailed deer ( Odocoileus virginianus). This species is an important component of human diet in tropical habitats. The objectives of this study were to: 1) compare density estimates using four methods: counts in circular plots (FSC, Fecal Standing Crop and FAR, Fecal Accumulation Rate), and counts in transects (LT, Line Transect and ST, Strip Transect); 2) simulate the effect of increased sampling effort on density and precision, and; 3) evaluate the effort required to detect changes in population density using LT. From 2006 to 2007, we intensively sampled a 1 km2quadrant in a Mexican tropical dry forest. The results indicate that all four methods produce similar mean population density estimates. However, estimates of precision were dependent on sample size which in turn was associated with the particular counting method used. In descending order of estimate precision, the methods ranked as: LT, ST, FSC, and FAR. To detect population changes of < 20%, we suggest the establishment of 5 to 22 transects (LT) of 390 m during the dry season. To reduce bias in density estimation, it is important to obtain defecation and pellet decomposition rates in the study site.

Is deer herbivory directly proportional to deer population density? Comparison of deer feeding frequencies among six forests with different deer density

The intensity of deer herbivory, rather than simply the deer population density, directly affects the forest ecosystem, but a linear relationship between these two factors has generally been assumed. To assess their relationship, we investigated deer population density and tree sapling vegetation in six forests with different deer density on Yakushima Island, Japan. The feeding frequency was used as an index of deer herbivory. Palatable saplings showed high feeding frequency and became rare in deer-abundant areas, while unpalatable saplings showed low feeding frequency and increased with increasing deer density. In addition, feeding frequency on sapling vegetation did not continue to increase with increasing deer population and was limited to only 0.24–0.32 in deer-abundant areas (more than 20 deer/km 2). These data suggest that deer shift their main food items from living palatable saplings to other alternatives such as litter fall rather than living unpalatable saplings. Clearly, the nonlinear relationship between deer density and deer herbivory on forest vegetation could result from a change in the food eaten by deer, and it is therefore necessary to assess the impacts of deer based on not only the size of the deer population but also the intensity of direct herbivory.

A proposal of the method of deer density estimate without fecal decomposition rate: a case study of fecal accumulation rate technique in Japan

AbstractThe accuracy of estimating deer density using the fecal pellet count method is greatly limited by variability of the fecal decomposition rate. The fecal accumulation rate technique can avoid the issue of decomposition rate. However, the precision of this technique is not clear when the decomposition rate is relatively high, such as in Japanese forests. We estimated deer population densities on Yakushima Island by the fecal accumulation rate technique and compared them between seasons. The estimated densities were similar to reported estimates, and did not differ seasonally, in accord with reports that deer on Yakushima do not migrate seasonally. Thus, we conclude that the fecal accumulation rate technique is applicable in Japanese forests.

Land-Use Pattern, Urbanization, and Deer–Vehicle Collisions in Alabama

With the rise in deer-vehicle collisions across the United States, the associated costs also have risen. Increasingly, however, researchers are learning that these collisions are not a random phenomena but follow a systematic pattern. Building on this insight, we explored the role of county characteristics in infl uencing the pattern and incidence of white-tailed deer- (Odocoileus virginianus) related auto collisions. Using county level data from 1994 to 2003 in Alabama, we tested several data models with the above mentioned factors as covariates. Our results showed that county characteristics, such as (1) having a deer population density (≥31/km 2 ), (2) being part of a metropolitan statistical area, (3) having a high proportion of pasture, urban and other land relative to woodland, and (4) having greater vehicle density per road km were more likely to increase the odds of deer-vehicle collisions. In contrast, high proportion of cropland relative to woodland, and wildlife management tools, such as increase in hunting license sales, and high deer bag limits, reduced the frequency of deer-vehicle collisions. These fi ndings suggested that urban planners need to consider the impact of urban development and infrastructure activities on deer habitat and densities, and how wildlife management strategies (e.g., judicious manipulation of bag limits and ways to promote hunting license sales) can be used along with other mitigation techniques to reduce deer-vehicle collisions.

Iodine Distribution in the Environment as a Limiting Factor for Roe Deer Antler Development

The iodine-containing hormones produced by the thyroid gland play a role in the complex neuro-hormonal regulation of antler development. The proper function of the thyroid depends on the adequate iodine supply of the organism, which is directly related to the iodine content of food and drinking water. The purpose of this study was to explore the connection between the iodine content of the water base, which has a strong correlation with the iodine concentration of environmental components available to animals, and the antler weight of roe deer (Capreolus capreolus) shot in Hungarian hunting areas. Using a general linear model, controlling for the collective effects of other environmental factors (deer population density, harvest rate, land use, and soil fertility information), the iodine content of the water base explained 51.4% of the total variance of antler weights. The results suggest that antler weights increase with increasing iodine concentration regardless of other factors; thus, the environmental iodine distribution can be a limiting factor suppressing roe deer performance assessed here as antler weight. Further experimental studies of controlled iodine uptake are needed to define the exact physiological iodine requirements of roe deer bucks.

Factors Affecting Autumn Deer–Vehicle Collisions in a Rural Virginia County

Vehicular collisions with white-tailed deer (Odocoileus virginianus) are a safety and economic hazard to motorists. Many efforts to reduce deer-vehicle collisions (DVCs) have proven unsuccessful, but deer reduction has been a primary management tool in several states. The Virginia Department of Transportation geo-located all known DVCs in Clarke County, Virginia, from August through December 2005 (n = 246) and 2006 (n = 259). We estimated harvest intensity, deer population density, amount of forest and housing development, presence of row crops, and traffi c volume and speed for 228 road segments (each 500 m in length) within the county to determine which factors are correlated with increased DVCs. A step-wise general linear model indicated that deer density (range 5-47 deer/km 2 ), and deer harvest levels (range 1-18 deer/km 2 for 9-km 2 blocks) were not correlated with the location of DVCs. Road attributes (traffi c volume and road type) and the amount of housing development were important attributes of road segments when predicting DVCs. The locations of DVCs during the rut were not markedly different from collisions outside the rut. Over the range of deer densities and harvest levels found in this rural county, there was little evidence that these factors infl uence the number of DVCs. Management efforts should include changing motorist behavior or road attributes.

Trillium grandiflorum height is an indicator of white-tailed deer density at local and regional scales

High densities of white-tailed deer ( Odocoileus virginianus) in the U.S.A. and Canada are reducing or preventing forest regeneration, and as a result, deer function as a keystone species in some sites. Management decisions about deer require reliable population density data, which are challenging to obtain at both regional and local scales. We tested the broad-scale applicability of the indicator species approach in which forage plant height was used to estimate deer density. The maximum heights of marked and unmarked plants of the widely distributed, spring-flowering polycarpic herb, white trillium ( Trillium grandiflorum) were measured across southern Ontario, Canada, over a 15-year period. A significant negative relationship was found at 10 sites between maximum plant height and estimates of deer population densities, which were derived from counts of live or culled animals and varied from 7 to 40 deers km −2. Maximum plant height could be reliably measured within a 4-week period. The underlying mechanism driving the negative relationship between plant height and deer density was attributed to deer preferentially selecting taller plants that grew less than ungrazed plants in the subsequent year. In 16 additional sites with locally high deer populations, the mean maximum height of T. grandiflorum appeared to be a more reliable indicator of deer density than estimates based on hunter returns across the broader regional scale of the Wildlife Management Unit. The ability to assess local scale white-tailed deer densities based on measuring heights of an easily identifiable, widespread plant, provides local residents and landowners with a tool for estimating the potential impacts of deer browsing and grazing in local woodlots and forests, improving local knowledge about herbivory pressure.

Browsing Patterns of White-Tailed Deer Following Increased Timber Harvest and a Decline in Population Density

We examined browsing patterns of white-tailed deer (Odocoileus virginianus) on a site in the central Appalachians that experienced a substantial (>50%) reduction in deer population density and an increase in the amount of timber harvest since 2001. We sampled woody browse in and immediately adjacent to 12 clearcuts ranging in age from 0–5 years postharvest in summer 2007. Clearcut-interior areas had higher woody browse abundance and browsing rates than clearcut-edge or mature forest areas. Woody browse abundance was slightly higher within individual clearcuts than in 2001 at higher population densities and lower timber harvest rates. Overall browsing rates declined from approximately 17% in 2001 to less than 5% during our study, suggesting that the combination of deer population control, and increasing the amount of timber harvest across the landscape can reduce herbivory to levels that may not impede growth and survival of forest vegetation.

Predation has a greater impact in less productive environments: variation in roe deer, Capreolus capreolus, population density across Europe

ABSTRACTAim We aimed to describe the large‐scale patterns in population density of roe deer Caprelous capreolus in Europe and to determine the factors shaping variation in their abundance.Location Europe.Methods We collated data on roe deer population density from 72 localities spanning 25° latitude and 48° longitude and analysed them in relation to a range of environmental factors: vegetation productivity (approximated by the fraction of photosynthetically active radiation) and forest cover as proxies for food supply, winter severity, summer drought and presence or absence of large predators (wolf, Canis lupus, and Eurasian lynx, Lynx lynx), hunter harvest and a competitor (red deer, Cervus elaphus).Results Roe deer abundance increased with the overall productivity of vegetation cover and with lower forest cover (sparser forest cover means that a higher proportion of overall plant productivity is allocated to ground vegetation and thus is available to roe deer). The effect of large predators was relatively weak in highly productive environments and in regions with mild climate, but increased markedly in regions with low vegetation productivity and harsh winters. Other potentially limiting factors (hunting, summer drought and competition with red deer) had no significant impact on roe deer abundance.Main conclusions The analyses revealed the combined effect of bottom‐up and top‐down control on roe deer: on a biogeographical scale, population abundance of roe deer has been shaped by food‐related factors and large predators, with additive effects of the two species of predators. The results have implications for management of roe deer populations in Europe. First, an increase in roe deer abundance can be expected as environmental productivity increases due to climate change. Secondly, recovery plans for large carnivores should take environmental productivity and winter severity into account when predicting their impact on prey.

Conformation to Bergmann's Rule in White-tailed Deer can be Explained by Food Availability

The body size of white-tailed deer (Odocoileus virginianus) increases with latitude and thus exhibits the pattern predicted by Bergmann's rule on the basis of surface to volume ratios and heat loss. This pattern is more simply explained by the distribution of food available per individual animal, which is driven by two factors, the net primary production (NPP) of plants and deer population density. Food availability is often overlooked as a cause of an increase in body size in large terrestrial herbivores in temperate latitudes because of a fundamental misconception about the global distribution of plant productivity. Within a small latitudinal range, white-tailed deer body size as evidenced by modern deer and Holocene paleozoological remains is inversely related to population density and directly related to food availability. Food availability per animal is a product of plant productivity and population density, and is correlated with both local and regional body size variability. These local and regional food-body size patterns are consistent with recent analyses of global NPP datasets which show that ecologically relevant NPP is highest in the north temperate latitudes where white-tailed deer attain their largest body size.

Application of fecal pellet group count to sika deer (Cervus nippon) population monitoring on Mt. Ohdaigahara, central Japan

ABSTRACT The relationship between the number of fecal pellet groups found in line transects and estimates of deer density based on block counts on Mt. Ohdaigahara in central Japan was examined and the validity of fecal pellet group counts for obtaining an index of sika deer population density was assessed. Sika deer population densities estimated by block count were 13.0/km2 in spring, 18.3/km2 in summer and 19.0/km2 in autumn. Fecal pellet group counts showed low positive correlations with deer density in spring and autumn (0.69 in spring and 0.68 in autumn), but not in summer, indicating that deer density may not be predictable then. We suggest that fecal pellet group count reflects deer density in spring or autumn, and might be feasible as an index of deer population density.

Probability of recent bark stripping damage by red deer (Cervus elaphus) on Norway spruce (Picea abies) in a low mountain range in Germany – a preliminary analysis

Red deer (Cervus elaphus) can cause considerable damage to forest stands by bark stripping. Here, we examined the probability of bark stripping of susceptible Norway spruce (Picea abies) during winter in relation to local environmental characteristics in the western Harz Mountains, Lower Saxony, Germany. We present the results of a multiple logistic regression model for recent bark stripping damage by red deer which we developed from two systematic cluster sampling inventories after two winter periods along with associated meteorological data and records of bagged deer. Our model suggests that the risk of bark stripping increased significantly (P  0.05) with rising slope angle, cumulating snow depth and increasing index values of red deer population density. Spruces growing in closed forest stands were debarked at a higher probability than spruces located close to forest edges. Further on, spruce stands on eastern slopes had a lower probability of bark damage than spruce stands on northern slopes. Other tested variables (altitude, length of daily solar irradiation, duration of snow cover, age of spruce stand within the age range of 16–50 years) had no significant effect on the probability of new bark stripping. We conclude that red deer in the western Harz Mountains seem to use bark as food resource at preferred locations and in times of low food availability. To improve fit and predictive power of bark stripping models we recommend including stand characteristics. We propose to reduce the population size of red deer in order to diminish bark stripping damages to an economically acceptable level.

Johne's Disease in a Free-Ranging White-tailed Deer from Virginia and Subsequent Surveillance for Mycobacterium avium subspecies paratuberculosis

Johne's disease (paratuberculosis) was diagnosed in a 2-yr-old, male, free-ranging white-tailed deer (Odocoileus virginianus) from Fauquier County, Virginia, USA, based on histopathology and culture for Mycobacterium avium subspecies paratuberculosis. Clinical and pathologic findings included emaciation; loss of body fat; chronic diarrhea; severe, chronic, diffuse granulomatous colitis with intrahistiocytic acid-fast bacilli; moderate, chronic granulomatous lymphadenitis with intrahistiocytic acid-fast bacilli; as well as moderate chronic, multifocal, lymphoplasmacytic hepatitis. These findings are consistent with previous reports of Johne's disease in cervids. Subsequent targeted surveillance of 10 emaciated deer with diarrhea, as well as sampling of 72 asymptomatic deer for M. avium subsp. paratuberculosis using culture of multiple tissue types, as well as serology using an enzyme-linked immunosorbent assay (ELISA) optimized for cervid antibody detection, did not reveal any additional cases of infection in this geographic region. To date, this appears to be an isolated case of Johne's disease in a free-ranging white-tailed deer, and infection with the causative agent for Johne's disease appears to be an infrequent occurrence in deer from this region. The origin of infection was most likely domestic ruminants. This is the first report of clinical Johne's disease in a free-ranging white-tailed deer outside of the Florida Keys, USA. Stressors, such as high deer population density and low selenium levels, may have contributed to the development of clinical disease in this case and warrant further investigation.

Population-level effects of immunocontraception in white-tailed deer (Odocoileus virginianus)

In North America, dense populations of white-tailed deer (Odocoileus virginianus) in suburbs, cities and towns have stimulated a search for new population-management tools. Most research on deer contraception has focused on the safety and efficacy of immunocontraceptive vaccines, but few studies have examined population-level effects. We report here results from two long-term studies of population effects of the porcine zona pellucida (PZP) immunocontraceptive vaccine, at the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, USA, and at Fire Island National Seashore (FIIS), New York, USA. Annual population change at NIST was strongly correlated with population fertility (rP = 0.82, P = 0.001); when population fertility at NIST dropped below 0.40 fawns per female, the population declined. Contraceptive treatments at NIST were associated with a 27% decline in population between 1997 and 2002, and fluctuated thereafter with the effectiveness of contraceptive treatments. In the most intensively treated segment of FIIS, deer population density declined by ~58% between 1997 and 2006. These studies demonstrate that, in principle, contraception can significantly reduce population size. Its usefulness as a management tool will depend on vaccine effectiveness, accessibility of deer for treatment, and site-specific birth, death, immigration, and emigration rates.