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1.
Few studies have evaluated how wildlife, and white-tailed deer (Odocoileus virginianus) in particular, respond to Conservation Reserve Program (CRP) grasslands. We conducted a 3-year study (2007–2009) to determine the influence of CRP on fawn ecology during a time of declining CRP enrollment. We captured and radiocollared 81 fawn white-tailed deer during 15 May to 15 June 2007–2009 in north-central South Dakota, collected 6,505 locations, and documented 70 summer home ranges. Mean summer home ranges increased temporally during 2007–2009 (P < 0.001) and corresponded to a 41% loss of CRP grasslands in the area (2.3% loss in land cover and approx. 21% loss in cover habitat in the study area) over the duration of the study. Additionally, mean movement between daily locations increased (P < 0.001) from 2007 to 2009. Analysis of covariance models indicated that change in CRP influenced home-range size, and change in CRP and wheat influenced daily movement. Smaller home ranges and reduced movements were associated with greater quantity of CRP available to fawns, and increased movements were associated with more acreage of wheat available to fawns. Fawns shifted resource selection during the summer at a mean age ranging from 48.8 days to 58.6 days, and this shift was associated with height of corn (83–87 cm). During early summer, fawns consistently selected for CRP; selection of wheat progressed temporally from avoidance in 2007 to selection in 2009. During late summer, fawns consistently selected for corn habitat and used CRP at least in proportion to its availability. Reduction in CRP-grasslands seemed to increase fawn home-range size and daily movements and, influenced change in resource selection to wheat. Current legislation mandates continued decrease in CRP enrollment and concomitant increase in the planting of corn for ethanol production. Management of habitat throughout the grasslands of the Northern Great Plains that maximizes cover habitats would provide neonates with adequate cover for protection from predators. © 2011 The Wildlife Society.  相似文献   

2.
Abstract: Exurban development is nonmetropolitan, residential development characterized by a human population density and average property size intermediate between suburban and rural areas. Although growth in exurban areas is outpacing that of urban, suburban, or rural landscapes, studies of deer (Odocoileus spp.) ecology in exurban areas are nonexistent. During 2003–2005, we studied space use (i.e., seasonal home-range and core-area size and habitat use relative to human dwellings) and survival of 43 female white-tailed deer (O. virginianus) in an exurban setting near Carbondale, Illinois. Deer had larger home ranges than most suburban deer populations and generally smaller home ranges than rural deer populations. When we analytically controlled for habitat use, deer exhibited a subtle avoidance of human dwellings, especially during the fawning season. The annual survival rate was among the highest reported in the literature at 0.872 (SE = 0.048). Only 5 deer (cause-specific mortality rate = 0.091) were harvested by hunters, indicating major obstacles for wildlife managers when attempting to manage deer in exurban areas using traditional hunter harvest.  相似文献   

3.
The home-range dynamics and habitat selection of nine roe deer were studied from March 1994 to August 1994 in the Maremma Natural Park along the Tyrrhenian coast of Italy. The habitat was highly fragmented, with open agricultural fields prevailing in the study area (57%); the climate was Mediterranean. Data on spatial behaviour were collected by radio-tracking techniques. Habitat selection and structure were investigated by compositional and landscape analysis, both within the study area and within the home ranges. Animals of our sample showed spatial-use patterns varying from stationary to roaming. Stationary individuals used small home ranges while roaming ones moved, especially during the reproductive period in July and August. The percentage and structure of woodlands influenced the size of home ranges and the behaviour of males: stationary males used large amounts of woodlands within their home ranges and showed a territorial behaviour whereas males that used a high percentage of fields showed wider home ranges even during the territorial period. Females seemed to be less influenced by the presence and patch-structure of woodland within their home range. Landscape structure and habitat composition seemed to be important factors influencing the spatial behaviour of this roe deer population.  相似文献   

4.
Abstract: Wildlife researchers often test whether animals use resources disproportionately relative to availability (i.e., selectively). However, the traditional estimate of availability at the landscape scale (resource proportions on the landscape) may be inaccurate and lead to false conclusions. We calculated the chance of falsely finding selection (type I error rate) when the traditional estimate of availability is used. True availability was estimated by Monte Carlo simulations with randomly located home ranges and compared to the traditional estimate to calculate type I error rates. Tests were conducted with α = 0.05 for different home-range sizes (1 to 1,000 km2) and 4 habitat patterns. Landscape proportions did not equal proportions of habitats in random home ranges (traditional estimate ≠ true availability). Type I error rates were ≥0.24 and increased with number of animals tested and decreased with home-range size and number of habitats. Therefore, researchers should use randomly located home ranges instead of landscape proportions to estimate availability at the landscape scale. We evaluated a goodness-of-fit test for comparing habitat proportions between randomly located home ranges and observed home ranges. Type I error rates for this method were ≤0.08, regardless of number of animals, home-range size, and number of habitats tested. We evaluated this method for 2 species with different home-range sizes and predicted habitat selection patterns: mountain lions (Puma concolor, ∼ 700 km2, relatively nonselective) and mule deer (Odocoileus hemionus, ∼ 16 km2, relatively selective). This method yielded results consistent with predictions, whereas the traditional method using landscape proportions to estimate availability did not. Randomly located, simulated home ranges are superior to landscape proportions for estimating availability.  相似文献   

5.
Abstract: The scale at which populations use landscapes influences ecological processes and management. We used dispersal and home-range data of 3 age groups of male white-tailed deer (Odocoileus virginianus) to determine the scale at which management will be effective. Home-range size at 5.5 years of age (182 ha ± 24.9 SE) was 56% smaller (P < 0.001) than home-range size of the same 13 males as yearlings (416 ± 59.4 ha). Percent overlap of yearling and 5.5-year-old home ranges was 62.7 6 10.3% (n = 13). Distance between home-range centers of yearling and mature deer was 1,264.9 ± 407.4 m, including 3 deer that dispersed after 2.5 years of age. Average 95% fixed-kernel home-range size was 207.4 ± 20.4 ha and 225.7 ± 30.1 ha for all mature males in years 1 and 2 of our study, respectively. We found that properties >10,000 ha were needed to manage >50% of original yearling males found on the property, whereas properties of 4,500 ha would maintain 50% of original middle-aged (2.5-4.5 yr of age) and mature males (≥4.5 yr of age). Movements after dispersal were minimal, with deer shifting their center of activity <600 m and <350 m each year for middle-aged and mature males, respectively. These data could be used by managers developing management plans, recommending harvest rates, and interpreting harvest data of male white-tailed deer and by biologists attempting to understand ecological processes such as spread of disease.  相似文献   

6.
We studied home range and habitat selection of radio-marked adult California spotted owls (Strix occidentalis occidentalis) randomly selected from among the breeding population of owls in the central Sierra Nevada, California from June to October 2006. The most parsimonious home-range estimate for our data was 555 ha (SE = 100 ha). Home-range size was positively correlated with the number of vegetation patches in the home range (habitat heterogeneity). We used resource selection ratios to examine selection of vegetation types by owls within our study area. Owl home ranges contained a high proportion of mature conifer forest, relative to its availability, although the confidence interval for this estimate overlapped one. We also used resource selection functions (RSF) to examine owl foraging habitat selection. Relative probability of selection of foraging habitat was correlated with vegetation classes, patch size, and their interaction. Owls showed highest selection rates for large patches (>10 ha) of pole-sized coniferous forest. Our results suggested that spotted owls in the central Sierra Nevada used habitat that contained a high proportion of mature conifer forest at the home-range scale, but at a finer scale (foraging site selection) owls used other vegetation classes interspersed among mature forest patches, consistent with our hypothesis that spotted owls may use other forest types besides old growth and mature forests when foraging. Our study provides an unbiased estimate of habitat use by spotted owls in the central Sierra Nevada. Our results suggest that forest managers continue to protect remaining mature and old-growth forests in the central Sierra Nevada because owl home ranges contain high proportions of these habitats. However, our results also showed that owls used younger stands as foraging habitat so that landscape heterogeneity, with respect to cover types, may be an important consideration for management but we did not attempt to relate our findings to fitness of owls. Thus management for some level of landscape heterogeneity for the benefit of owls should proceed with caution or under an adaptive management framework. © 2011 The Wildlife Society.  相似文献   

7.
ABSTRACT.   Identifying and protecting breeding habitat for imperiled species requires an understanding of the spatial and temporal movements of breeding individuals. During the 2003 and 2004 breeding seasons, we examined space use by Piping Plovers ( Charadrius melodus ) in the federally endangered Great Lakes population. We used coordinate geometry to estimate home range sizes of individual birds and examined relationships between home range size and breeding stage (incubation versus chick rearing), year, sex, number of locations, minimum plover age, distance to the nearest nest, and human beach use (high, medium, or low). The mean size of home ranges of Piping Plovers that fledged at least one chick was 2.9 ± 0.5 (SE) ha (range = 0.4–11.2 ha), and the mean linear beach distance traversed was 475 ± 53 m (range = 130–1435 m). Individuals used 3 times more beach area and 1.5 times more shoreline distance in 2003 than in 2004. Females used smaller areas than males overall and during chick rearing. Home ranges were smallest on beaches with low public use, suggesting that human disturbance may cause greater movement by individual plovers and that larger protected areas may be warranted on beaches frequented by the public to minimize disturbance to breeding birds. Our results demonstrate that nesting Great Lakes Piping Plovers occupy relatively small ranges and, therefore, that even relatively small areas of suitable habitat can have a high conservation value for this endangered population. However, the total area of habitat used varied substantially among individuals, and this should be considered when protecting habitat for the species.  相似文献   

8.
A better understanding of habitat use and home range size for an exotic fallow deer (Dama dama L.) population in coastal Georgia is needed to understand the relationship between this introduced species and the barrier island ecosystem. These spatial requirements will aid in management decisions to limit negative impacts to the deer or sensitive habitats. We describe annual and seasonal home range and habitat use of seven fallow deer fitted with GPS collars. Home ranges of females averaged 130.3 ± 0.45 ha based on a 95% local convex hull (LoCoH) nonparametric kernel method. Home ranges of adult males were highly variable, ranging from 56.9 to 354.8 ha. We examined site fidelity by analyzing shifts in core areas and percent overlap across seasons. Only one individual exhibited a seasonal range shift; all other deer demonstrated a high level of site fidelity. Based on compositional analysis of habitat use versus availability, fallow deer avoided salt marshes but showed individual variation in selection of other habitats. Maritime shrub was the most commonly preferred habitat type on the barrier island. Fallow deer have adapted to effectively use available habitats on the barrier island and have successfully excluded native white-tailed deer from recolonizing LSSI.  相似文献   

9.
Geoffroy's cat Oncifelis geoffroyi is a little-known South American small felid. We report data on the spatial ecology of four adults (two males and two females) that were radiotracked in an area of wet grassland of the Argentine Pampas from February 2000 to April 2001. The mean home range size varied from 248 ha [90% minimum convex polygon (MCP)] to 342 ha (100% MCP), with male home ranges c . 2.5 larger than those of females. Home range overlap averaged 44.7%, and was more extensive between males than between females but it decreased markedly when outliers were excluded. Forest patches were used more than expected by their availability within home ranges. These patches hosted many large defecation sites, possibly acting as 'communication centres' where information was exchanged among individuals in the form of scent marks. Despite the lack of a clear preference for tall grasslands, this was the most frequently used habitat. We argue that natural grasslands in the Pampas ecoregion are important for O. geoffroyi and that their alteration can affect the conservation status of this cat. The comparison of our data with those reported previously suggests that Geoffroy's cat can show a certain degree of flexibility in its spatial behaviour.  相似文献   

10.
Accuracy of resource selection functions across spatial scales   总被引:2,自引:0,他引:2  
Resource selection functions (RSFs) can be used to map suitable habitat of a species based on predicted probability of use. The spatial scale may affect accuracy of such predictions. To provide guidance as to which spatial extent or grain is appropriate and most accurate for animals, we used the concept of hierarchical selection orders to dictate extent and grain. We conducted a meta-analysis from 123 RSF studies of 886 species to identify differences in prediction success that might be expected for five selection orders. Many studies do not constrain spatial extent to the grain of the next broader selection order in the hierarchy, mixing scaling effects. Thus, we also compared accuracy of single- vs. multiple-grain RSFs developed at the unconstrained extent of an entire study area. Results suggested that the geographical range of a species was the easiest to predict of the selection orders. At smaller scales within the geographical range, use of a site was easier to predict when environmental variables were measured at a grain equivalent to the home-range size or a microhabitat feature required for reproduction or resting. Selection of patches within home ranges and locations of populations was often more difficult to predict. Multiple-grain RSFs were more predictive than single-grain RSFs when the entire study area was considered available. Models with variables measured at both small and large (> 100 ha) grains were usually most predictive, even for many species with small home ranges. Multiple-grain models may be particularly important for species with moderate dispersal abilities in habitat fragments surrounded by an unsuitable matrix. We recommend studies should no longer address only one grain to map animal species distributions.  相似文献   

11.
12.
The manner by which animals use space and select resources can have important management consequences. We studied patterns of habitat selection by northern bobwhites (Colinus virginianus) on Babcock-Webb Wildlife Management Area, Charlotte County, Florida and evaluated factors influencing the sizes of their home ranges. A total of 1,245 radio-tagged bobwhites were monitored for 19,467 radio days during 2002–2007. The mean ( ± 1 SE) annual home range size, estimated using the Kernel density method, was 88.43 ( ± 6.16) ha and did not differ between genders. Winter home ranges of bobwhites (69.27 ± 4.92 ha) were generally larger than summer home ranges (53.90 ± 4.93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots compared to those that did not; however, the presence of food plots did not influence summer home ranges. We used distance-based methods to investigate habitat selection by bobwhites at two scales: selection of home ranges within the study site (second-order selection) and selection of habitats within home ranges (third-order selection). Across both scales, bobwhites generally preferred food plots and dry prairie habitat and avoided wet prairies and roads. This pattern was generally consistent between genders and across years. Our data indicate that management practices aimed at increasing and maintaining a matrix of food plots and dry prairie habitat would provide the most favorable environment for bobwhites.  相似文献   

13.
Abstract: Identifying how habitat use is influenced by environmental heterogeneity at different scales is central to understanding ungulate population dynamics on complex landscapes. We used resource selection functions (RSF) to study summer habitat use in a reintroduced and expanding elk (Cervus elaphus nelsoni) population in the Chequamegon National Forest, Wisconsin, USA. Factors were examined that influenced where elk established home ranges and that influenced habitat use within established home ranges. We also determined grain sizes over which elk responded to environmental heterogeneity and the number of categories of habitat selection from low to high that the elk distinguished. At a large spatial extent, elk home-range establishment was largely explained by the spatial distribution of wolf (Canis lupus) territories. Forage abundance was also influential but was relatively more important at a small spatial extent when elk moved within established home ranges. Areas near roads were avoided when establishing a home-range, but areas near roads were selected for use within the established home range. Elk distinguished among 4 different categories of habitat selection when establishing and moving within home ranges. Spatial and temporal cross validation demonstrated that to improve the predictive strength of habitat models in areas of low inter-annual variability in the environment, it is better to follow more individuals across diverse environmental conditions than to follow the same individuals over a longer time period. Last, our results show that the effects of environmental variables on habitat use were scale-dependent and reemphasize the necessity of analyzing habitat use at multiple scales that are fit to address specific research questions.  相似文献   

14.
蜂桶寨自然保护区小熊猫巢域初步研究   总被引:4,自引:2,他引:2  
2002年5~11月,在蜂桶寨自然保护区利用无线电遥测技术对6只小熊猫的巢域利用进行了初步研究。结果表明,6只戴颈圈个体M1、M2、M3、F1、F2、F3的巢域面积分别为330·26hm~2、135·18hm~2、190·67hm~2、98·23hm~2、141·60hm~2、204·80hm~2;雄性个体平均巢域面积为218·70hm~2,雌性个体为148·21hm~2。小熊猫个体间巢域重叠普遍,平均重叠率达25·33%,其中雄性个体之间为26·00%,雌性个体之间为23·67%,两性个体之间为25·67%。可能受人为干扰的影响,M1在6只监测个体中巢域面积、日均移动距离均为最大。  相似文献   

15.
The effect of experimental manipulation of population density on home-range size was investigated in two free-ranging roe deer (Capreolus capreolus) populations under contrasting environmental conditions. In these two long-term monitoring studies, one in Bogesund, Sweden (12 years) and one in Dourdan, France (10 years), deer density varied fourfold through varying culling pressure. Home-range data were collected by radio-tracking across the periods of contrasting density of the studies. We predicted that home-range size for females should vary in relation to the level of feeding competition, while for males, competition for mating opportunities should also influence range size, at least in summer when roe bucks are territorial. We found a highly consistent pattern over the two populations, with strong effects of deer density on home-range size, as well as significant differences between winter and summer ranges and between the sexes. Home ranges were consistently smaller at high density compared to low density. Males had larger ranges than females and this was particularly so during summer. Lastly, winter ranges were generally larger than summer ranges, particularly among females, although males at Dourdan had larger summer ranges compared to winter ranges. We suggest that the reduction of range size at high deer density during winter, as well as summer, is linked to the solitary behaviour and territorial social system of roe deer, with possible effects of dominance rank, even outside the mating season.  相似文献   

16.
The huemul Hippocamelus bisulcus is an endangered species of deer occupying temperate woodland habitats in the Andes of southern Chile and Argentina. Continuing declines due to a combination of hunting and habitat loss have created a need for more conservation measures. However, current information on ranging behaviour, dispersal and seasonal movements is very limited. Three sites were therefore selected in Aysén, Chilean Patagonia, to study the movements and habitat associations of huemul. Although seasonal migrations in elevation had been reported previously for the species, we found the extent of seasonal movement limited, much less than that reported for other deer species in mountainous environments. Huemul selected mid-slope elevations, and the winter ranges of most animals overlapped summer ranges. The extent of the seasonal movements that were undertaken were, however, the greatest at the highest site and insignificant at the lowest site. Previously published information shows that habitats used by huemul follow a latitudinal gradient in elevation (reducing c . 100 m °S−1 in latitude), and our results suggest that seasonal movements are likely to be greater in sites above this line. The mean range size differed between sites, ranging from 357 to 656 ha (mean 444 ha; median 506 ha). These estimates excluded long-distance (>5 km) movements, which were infrequent.  相似文献   

17.
Factors affecting activity, habitat use, and home-range size of the red fox were analysed in a highly heterogeneous rural environment. Individual differences in behaviour were used to test our hypotheses. Food habits tended to depend on food availability, which, in turn, was mainly influenced by temperature. Diet was highly heterogeneous. Insects, e.g. grasshoppers and beetles, and cultivated fruits were the staple of the diet, but no diet component stood out clearly from all others. For an opportunistic species such as the fox, habitat heterogeneity may be the main factor underlying a wide trophic niche. All foxes selected the vineyard as part of their home ranges, whereas they preferred for activity the abandoned olive-yard among the habitats of their home ranges. Human intolerance of foxes affects their pattern of activity, habitat selection, and ranging behaviour. Foxes were strongly nocturnal. Cover-rich habitats were preferred for resting and for movements in daylight. Areas under human management were mainly used at night. Selectivity was higher for resting than for activity sites. Variation in home-range size and shape can be influenced not only by the dispersion of the main food patches, but also by the location of shelters  相似文献   

18.
The home range behaviour and habitat selection by Red deer ( Cervus elaphus L. ) in a mixed-age Sitka spruce plantation was studied from1979–82 using radio-telemetry. Females used areas with rides, young replanted and pre-thicket crops, older stands where there were checked trees, more in proportion to availability than old closed-canopy stands, open-hill ground and high-elevation newly-established forest. They used open areas more at night, dusk and dawn, and the more secluded thickets during the day. Compared to females, young males were found more in older stands, high-altitude young plantation and on open-hill ground.
Home range size (406–1008 ha for females and1062–3059 ha for males) was smaller for animals with a high proportion of favourable habitats in their range, although larger range size did not incorporate a higher total area of favourable habitat. Individual ranges overlapped.
Females used the same range from season to season and from year to year. Intensity of range usage is discussed. Males dispersed a mean distance of 15 km from their area of capture during their first or second year of age. One young male used different areas each season after dispersal. Females centred their activity in the same river catchment from season to season, but male activity centres changed from one catchment to another.
Comparison is made with the results of studies of habitat selection in the same forest using dung-accumulation techniques, and with the ranging behaviour of Red deer on open-hill ground.  相似文献   

19.
Abstract: Manipulation of forest habitat via mechanical thinning or prescribed fire has become increasingly common across western North America. Nevertheless, empirical research on effects of those activities on wildlife is limited, although prescribed fire in particular often is assumed to benefit large herbivores. We evaluated effects of season and spatial scale on response of Rocky Mountain elk (Cervus elaphus) and mule deer (Odocoileus hemionus) to experimental habitat manipulation at the Starkey Experimental Forest and Range in northeastern Oregon, USA. From 2001 to 2003, 26 densely stocked stands of true fir (Abies spp.) and Douglas-fir (Pseudotsuga menziesii) were thinned and burned whereas 27 similar stands were left untreated to serve as experimental controls. We used location data for elk and mule deer collected during spring (1 Apr-14 Jun) and summer (15 Jun-31 Aug) of 1999–2006 to compare use of treated and untreated stands and to model effects of environmental covariates on use of treated stands. In spring, elk selected burned stands and avoided control stands within the study area (second-order selection; large scale). Within home ranges (third-order selection; small scale), however, elk did not exhibit selection. In addition, selection of treatment stands by elk in spring was not strongly related to environmental covariates. Conversely, in summer elk selected control stands and either avoided or used burned stands proportional to their availability at the large scale; patterns of space use within home ranges were similar to those observed in spring. Use of treatment stands by elk in summer was related to topography, proximity to roads, stand size and shape, and presence of cattle, and a model of stand use explained 50% of variation in selection ratios. Patterns of stand use by mule deer did not change following habitat manipulation, and mule deer avoided or used all stand types proportional to their availability across seasons and scales. In systems similar to Starkey, manipulating forest habitat with prescribed fire might be of greater benefit to elk than mule deer where these species are sympatric, and thus maintaining a mixture of burned and unburned (late successional) habitat might provide better long-term foraging opportunities for both species than would burning a large proportion of a landscape.  相似文献   

20.
Abstract: For many wildlife species, agricultural landscapes undergo spatial and temporal fluctuations in the composition of food and cover annually with the planting and harvesting of crops. Raccoon (Procyon lotor) populations have flourished in agricultural landscapes, where crops increase foraging opportunities and efficiencies. However, information is lacking regarding the effects of temporal shifts in food and cover resulting from agricultural activities on raccoon home ranges. We examined home-range characteristics of 60 (33 M, 27 F) adult raccoons in northern Indiana, USA, from May 2003 through June 2005 to identify shifts in the size of home ranges and core use areas among seasons defined by crop availability and crop developmental stages. Mean fixed-kernel home-range (92 ± 6 ha; xM ± SE) and core-area sizes (20 ± 2 ha) of males were significantly larger than those of females (58 ± 7 ha and 13 ± 2 ha, respectively), and both were smaller than those reported for raccoons in other fragmented agricultural landscapes. Home-range sizes varied little among seasons for either sex. However, home ranges of males were smallest during the crop maturation stage, whereas home ranges of females were smallest during the crop growing season. The results of our study suggest that even in expansive rural landscapes, raccoons can maintain small home ranges when food, water, and denning resources are readily available. Additionally, the lack of differences among seasonal home-range sizes, despite the presence of an ephemeral superabundant food source (i.e., corn) during the maturation season, was likely due to the close proximity of foraging and denning resources across seasons.  相似文献   

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