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1.
ABSTRACT Status assessment of endangered Florida Key deer (Odocoileus virginianus clavium) is currently limited by a paucity of information regarding population estimates for outer islands, which collectively comprise approximately 70% of potential habitat within the Key deer range. Practical limitations and financial considerations render traditional survey techniques impractical for application on remote outer islands. Our objective was to evaluate the utility of infrared-triggered cameras to estimate Key deer abundance on outer islands. We used digital infrared-triggered cameras and mark-resight methods to estimate Key deer abundance on 20 outer islands. Abundance estimates for primary subpopulations ranged from 15 to 16 for Howe Key, 5 to 10 for Knockemdown complex, and 13 to 17 for Little Pine Key. Other island complexes such as Ramrod Key, Water Key, and Annette complex maintain only small subpopulations (i.e., ≤5 individuals) and other previously inhabited island complexes (e.g., Johnson complex and Summerland Key) no longer maintain subpopulations. Key deer abundance was well below estimated carrying capacities on all outer islands, with larger natural populations occurring closest to Big Pine Key. Our results suggest that camera-based surveys offer a practical method to monitor abundance and population trends of Key deer on outer islands. Our study is the first to estimate Key deer abundance in these areas using technically structured model-based methods and provides managers with current and baseline information regarding Key deer subpopulations.  相似文献   

2.
  1. Theories of dispersal and senescence (or aging) predict that dispersal, and ongoing survival and body condition, are influenced by evolutionary drivers, along with intrinsic and extrinsic factors. Such theories are relevant to translocations of animals where high mortality, loss of body condition, and dispersal beyond the area of release are commonly reported. However, these theories have rarely been tested using data from translocations.
  2. We explore whether theories of dispersal and senescence, together with biological knowledge and management interventions, can predict rates of postrelease dispersal, survival and change in body condition of a translocated endangered meso‐predator, the eastern quoll Dasyurus viverrinus.
  3. Captive‐bred quolls (n = 60) from three sanctuaries were translocated to an unfenced, predator‐managed reserve (Booderee National Park) over 2 years (2018, 2019). Survival, dispersal and body mass were monitored via GPS/VHF tracking and targeted trapping for 45 days postrelease.
  4. We found support for the “social subordinate” hypothesis, with smaller quolls dispersing further. Consistent with theories of senescence and the biology of our species, survival was marginally greater for females, and females regained losses in body mass in both years following release. In contrast, males recovered body condition in the first but not the second release as this coincided with breeding. Quolls that originated from the mainland sanctuary were on average heavier at release and, after accounting for weight, dispersed further.
  5. Synthesis and applications. Using theory to test outcomes of wildlife translocations can provide insights into patterns across taxa and under different conditions, enabling useful improvements to future fauna translocations. This allows for better predictions to be made about the likelihood of success from proposed translocations, changes to planning to improve outcomes (e.g., modifying sex ratios, individual selection and release cohort), and improved animal welfare as fewer animals are subjected to trials.
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3.
Deer can have severe effects on plant communities, which in turn can affect insect communities. We studied the effects of Key deer herbivory on the incidence of insect herbivores that occur within deer habitats in the lower Florida Keys, within the National Key Deer Refuge (NKDR). We analyzed plant chemistry (tannins, nitrogen) and surveyed for the occurrence of insects (above the browse tier) among plant species that were either deer-preferred or less-preferred. Results indicated higher levels of foliar tannins on islands with fewer Key deer and larger amounts of foliar nitrogen on islands with a high density of Key deer. Consequently, leaf miners were significantly more abundant on islands with high deer density, irrespective of deer-preference of plant species. On islands with a high deer density, incidence of leaves damaged by chewing insects was lower on preferred plant species but greater on less-preferred species than on islands with fewer deer. No apparent patterns were evident in the distribution of leaf gallers among plant species or islands with different deer density. Our results imply that plant nutrition levels—either preexisting or indirectly affected by deer deposition—are more important than plant defenses in determining the distribution of insect herbivores in the NKDR. Although high densities of the endangered Key deer have negative effects on some plant species in the NKDR, it seems Key deer might have an indirect positive influence on insect incidence primarily above the browse tier. Further research is warranted to enable fuller understanding of the interactions between Key deer and the insect community.  相似文献   

4.
Monitoring postrelease establishment and movement of animals is important in evaluating conservation translocations. We translocated 39 wild pine martens Martes martes (19 females, 20 males) from Scotland to Wales. We released them into forested areas with no conspecifics in 2015, followed by a second release in 2016, alongside the previously released animals. We used radio‐tracking to describe postrelease movement and habitat selection. Six martens (15%) were not re‐encountered during the tracking period, of which four undertook long‐distance dispersal. For the remaining individuals, we characterized two phases of movement, “exploration” followed by “settlement,” that differed between releases. In the first release, martens remained in exploration phase for a mean of 14.5 days (SE = 3.9 days) and settled at a mean distance of 8.7 km (SE = 1.8 km) from release sites, whereas martens released in year two, alongside resident conspecifics, traveled away from release sites at a faster rate, settling sooner, at a mean of 6.6 days (SE = 1.8 days), but further, at a mean distance of 14.0 km (SE = 1.7 km) from release sites. Animals released in year one did not exhibit habitat preferences overall but within forests they favored recently felled areas, whereas animals released in year two showed strong selection for forested habitat but did not discriminate between forest types. The presence of conspecifics appeared influential for settlement and site fidelity of translocated martens and was associated with more rapid but more distant dispersal of the later cohort. Releases of animals in close proximity appeared to promote site fidelity and rapid establishment of ranges in the recipient environment.  相似文献   

5.
Movements of male white-tailed deer (Odocoileus virginianus) are of great concern with respect to spread of chronic wasting disease (CWD) across landscapes because most yearlings males disperse and adult males have higher prevalence of CWD than do females and younger deer. We radiocollared and monitored 85 male white-tailed deer in the middle Missouri River Valley of eastern Nebraska and western Iowa, USA from 2004 to 2008. Average size (±SE) of fixed-kernel annual home ranges (95%) and core areas (50%) for resident deer were 449 (±32) ha and 99 (±7) ha, respectively. Resident deer exhibited a high-degree of fidelity to their home ranges. Mean overlap between consecutive annual home ranges and core areas was 81% and 74%, respectively. Average dispersal distance was 17.7 ± 4.5 km (range = 3–121 km) for 22 radio-marked and 6 ear-tagged yearlings. Mean spring dispersal distance (25 km) was 150% greater than fall (10 km). Dispersal direction from Desoto National Wildlife Refuge (DNWR) was bimodal on a northwest to southeast axis that followed the Missouri River corridor. Of 22 yearlings that dispersed, 18 (82%) established adult home ranges within the river valley. Dispersal movements of yearling males represent the greatest risk for rapid spread of diseases from infected source populations. Disease management efforts in riparian habitats should target male fawns and yearling males for removal in areas within or immediately adjacent to river corridors. © 2011 The Wildlife Society.  相似文献   

6.
A pneumonia epidemic reduced bighorn sheep (Ovis canadensis) survival and recruitment during 1997-2000 in a population comprised of three interconnected wintering herds (Kenosha Mountains, Sugarloaf Mountain, Twin Eagles) that inhabited the Kenosha and Tarryall Mountain ranges in central Colorado, USA. The onset of this epidemic coincided temporally and spatially with the appearance of a single domestic sheep (Ovis aires) on the Sugarloaf Mountain herd's winter range in December 1997. Although only bighorns in the Sugarloaf Mountain herd were affected in 1997-98, cases also occurred during 1998-99 in the other two wintering herds, likely after the epidemic spread via established seasonal movements of male bighorns. In all, we located 86 bighorn carcasses during 1997-2000. Three species of Pasteurella were isolated in various combinations from affected lung tissues from 20 bighorn carcasses where tissues were available and suitable for diagnostic evaluation; with one exception, beta-hemolytic mannheimia (Pasteurella) haemolytica (primarily reported as biogroup 1(G) or 1(alphaG)) was isolated from lung tissues of cases evaluated during winter 1997-98. The epidemic dramatically lowered adult bighorn monthly survival in all three herds; a model that included an acute epidemic effect, differing between sexes and with vaccination status, that diminished linearly over the next 12 mo best represented field data. In addition to the direct mortality associated with epidemics in these three herds, lamb recruitment in years following the pneumonia epidemic also was depressed as compared to years prior to the epidemic. Based on observations presented here, pasteurellosis epidemics in free-ranging bighorn sheep can arise through incursion of domestic sheep onto native ranges, and thus minimizing contact between domestic and bighorn sheep appears to be a logical principle for bighorn sheep conservation.  相似文献   

7.
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   

8.
Recent improvements in genetic analyses have paved the way in using molecular data to answer questions regarding evolutionary history, genetic structure, and demography. Key deer are a federally endangered subspecies assumed to be genetically unique, homogeneous, and have a female-biased population of approximately 900 deer. We used 985 bp of the mitochondrial cytochrome b gene and 12 microsatellite loci to test two hypotheses: (1) that Key deer are isolated and have reduced diversity compared to mainland deer and (2) that isolation of the Florida Keys has led to a small population size and a high risk of extinction. Our results indicate that Key deer are indeed genetically isolated from mainland white-tailed deer and that there is a lack of genetic substructure between islands. While Key deer exhibit reduced levels of genetic diversity compared to their mainland counterparts, they contain enough diversity to uniquely identify individual deer. Based on genetic identification, we estimated a census size of around 1000 individuals with a heavily skewed female-biased adult sex ratio. Furthermore, our genetic and contemporary demographic data were used to generate a species persistence model of the Key deer. Sensitivity tests within the population viability analysis brought to light the importance of fetal sex ratio and female survival as the primary factors at risk of driving the subspecies to extinction. This study serves as a prime example of how persistence models can be used to evaluate population viability in natural populations of endangered organisms.  相似文献   

9.
In many parts of North America, deer (Odocoileus spp.) have adapted to live in urban areas and are a source of negative human-wildlife interactions. Management strategies such as culling, immunocontraceptives, sterilization, and translocation have been implemented to manage urban deer populations. In the East Kootenay region of southern British Columbia, urban mule deer (Odocoileus hemionus) populations have been increasing, whereas non-urban mule deer populations have decreased. In 2014 a non-urban mule deer research project began in the area and in 2016 an urban deer translocation trial was approved in the same region. We fit 121 non-urban deer with global positioning system (GPS)-collars and translocated 135 urban mule deer to non-urban areas, of which 57 were fit with GPS-collars. We tested if annual survival between urban translocated (i.e., translocated) and non-urban deer differed, and if translocated deer survival increased in subsequent years after translocation. We also determined if age, body condition, release site, capture area and distance between capture and release sites affected translocated deer survival. We evaluated if translocated deer exhibited different movement behaviors than non-urban deer by comparing probability of migration, maximum net displacement, home range size, and probability of crossing a paved road. Finally, during our study we observed some translocated deer return to a municipal area after translocation and assessed if any covariates such as age, release site, or capture city could help predict this behavior. Annual survival of translocated deer was 0.48 and was significantly lower than survival of non-urban deer, which was 0.77. We observed 20 of 57 collared translocated deer return to a town after translocation. Translocated deer had larger net displacements and larger seasonal home range sizes than non-urban deer. Non-urban deer were more likely to migrate than translocated deer and crossed fewer paved roads than translocated deer. The management effectiveness of translocation to reduce urban deer densities is mixed because annual survival of translocated deer may be lower than may be acceptable to some stakeholders. Additionally, some translocated deer returned to an urban area, and the large distances traveled by deer after translocation may unintentionally spread disease. © 2020 The Wildlife Society.  相似文献   

10.
ABSTRACT To maximize success, reintroduction programs generally select predator-free release areas having high habitat quality. Past studies provide little insight into recovery efforts where multiple, potentially novel, mortality hazards occur. The ability of translocated animals to cope with novel environments can be affected by both pre- and postrelease experiences with habitat and mortality risks. We experimentally released elk (Cervus elaphus) having different background experiences into an area where predators and hunters were prevalent and habitat quality varied. Using a competing risks approach, we predicted the postrelease survival of individuals and their fidelity to release areas as a function of animal source and postrelease encounters with forage resources and areas used by wolves (Canis lupus) or humans. Mortality patterns were consistent with prerelease exposure to mortality risks but not habitat differences among source areas. Wolf predation, poaching, and legal Native hunting were equivalent in magnitude and accounted for the majority of elk mortalities. Familiarity with either wolves or hunters prior to release yielded first-year survival rates 1.9-2.2 times greater than observed for animals naive to both risks. These 2 primary sources of mortality traded off temporally as well as spatially given the proximity of roads, which wolves avoided. The prevalence of forage resources in release areas increased fidelity to release sites but coincided with higher mortality risk during the critical first year, potentially setting an ecological trap for animals naïve to local risks. Translocated individuals largely mediated their respective vulnerabilities over time, showing second-year survival rates equivalent to resident elk. In addition to using source populations that are able to adjust to mortality risks in release areas, spatial and temporal variation in mortality risks might be exploited when planning releases to increase the success of translocations into risky landscapes. (JOURNAL OF WILDLIFE MANAGEMENT 71(2):541–554; 2007)  相似文献   

11.
We gathered data over a 3-year period (1988–1990) on two free-ranging, island populations of rhesus macaques (Macaca mulatta)to test hypotheses concerning birth seasonal asynchrony and the relationship between climate and reproductive seasonality. Rhesus macaques from Kashmir, India, were translocated to Key Lois in 1973 and from Key Lois to Raccoon Key in 1978. Both sites are low-lying mangrove islands in the Florida Keys. Floral diversity and abundance are greater on Raccoon Key than on Key Lois. Average maximal and minimal temperatures per month did not vary significantly between Raccoon Key and Key Lois over the 3-year period. Average minimal temperatures per month on Key Lois, but not Raccoon Key, varied significantly between years. There were no significant variations in either the amount or the dates of rainfall over the 3-year period for the study area. A combined total of 1524 births was recorded for Raccoon Key (N = 879) and Key Lois (N =645). The birth season on Raccoon Key began 6 weeks earlier than on Key Lois. Births were associated with warmer, rainier months on both islands. Conceptions were associated with cooler, drier months at both study sites. No significant correlations were found between the date of the onset of the summer rains and either median conception or median birth dates on Raccoon Key or Key Lois. Our results do not substantiate the hypothesis that the onset of rainfall, within the temporal period set by photoperiod, regulates seasonal reproduction in rhesus macaques. We suggest that reproductive seasonality in the study populations may be influenced by a variety of factors.  相似文献   

12.
Mitochondrial DNA (mtDNA) was used to characterize patterns of geographic variation among white-tailed deer (Odocoileus virginianus) populations in the southeastern United States. Fifteen restriction enzymes were employed to survey and map 99 restriction sites in 142 deer from 18 localities in five southeastern states. Phylogenetic analysis revealed three primary groups of haplotypes: (1) southern Florida and the Florida Keys, (2) the remainder of peninsular Florida northward to South Carolina, and (3) the Florida panhandle westward to Mississippi. Geographical heterogeneity in haplotype frequencies suggests that stochastic lineage sorting or isolation by distance are not important determinates of mtDNA differentiation among deer populations. The pattern of mtDNA variation in white-tailed deer is concordant spatially with those observed in unrelated taxa suggesting the common influence of historical biogeographic events. The data (1) support previous hypotheses that relate contemporary patterns of intraspecific phylogeography in northern Florida to the physiogeographic history of the region; and (2) suggest that genetic differentiation in southern Florida may be attributable to episodes of Pleistocene dispersal. Despite potentially high vagility and human intervention, ecological and demographic characteristics of deer have effectively preserved the historical pattern of intraspecific mtDNA differentiation.  相似文献   

13.
Translocation is an important component of northern bobwhite (Colinus virginianus) recovery efforts, given the scale of their decline and inability to rapidly recolonize recently restored habitat. Repopulating sites in northern latitudes that are distant from reliable source populations may require long-distance trap and transport from southern locales, potentially compounding existing obstacles for this renascent population recovery technique. The landscape connectivity hypothesis predicts that site fidelity and survival would be lower if release properties are small and fragmented and home range sizes would be smaller and dispersal distances would be lower if habitat quality at the release site is perceived to be high and the surrounding matrix is of low permeability. We evaluated this hypothesis to determine if northern bobwhite survival, site fidelity, and resource selection following translocation differed between 2 contrasting landscapes in the Mid-Atlantic region of the United States. We translocated 508 radio-collared northern bobwhites from northern Florida and southern Georgia, to small, fragmented properties on the eastern shore of Maryland and large, contiguous properties in southern New Jersey, USA. We monitored northern bobwhites via radio-telemetry from approximately 1 April through 30 September, 2015–2018, 2–7 times a week. Breeding season (182 days after release) survival varied among sites, and was generally higher at the 2 New Jersey release sites than at the 2 Maryland sites, yet an acclimation period is ostensibly required to obtain reasonable breeding survival estimates to elicit population growth. Site fidelity, maximum dispersal distances, and home range sizes were lower at the smaller, fragmented Maryland properties than the larger New Jersey properties. These results support the landscape connectivity hypothesis such that reduced connectivity in our study decreased site fidelity and survival. Temporal variation in survival was potentially an artifact of translocation stress or maladaptive behavior during initial acclimation to the release sites, indicating that higher stocking rates may be needed to provide adequate founder abundance for translocation success. Northern bobwhites used early-successional cover at all sites, though selection varied based on scale of analysis and landscape context. These vital rate estimates and resource use patterns should be used to guide future translocations within the Mid-Atlantic, provide perspective for this population restoration technique range wide, and stimulate further investigation into limiting factors. © 2020 The Wildlife Society.  相似文献   

14.
Wildlife translocations, the deliberate movement of wild individuals from one part of their distribution to another, are increasingly being used as a conservation tool. Despite the popularity of translocations as a conservation technique, translocations are often not successful as a result of excessive movement, poor release site fidelity, and low survival. This study compares the movement patterns, site fidelity, and survival probability of resident and hard-released musk turtles (Sternotherus odoratus) in a complex of patchy distributed wetlands. Our results are different from most translocation studies as the majority of translocated turtles had movement (minimum convex polygon area, total distance moved, number of wetlands used, and the number of movement shifts between wetlands), release site fidelity, and wetland fidelity patterns that were similar to resident turtles. In addition, the survival probabilities of resident and translocated turtles were both high. We believe the combination of poor overland movement capabilities and the patchy distribution of wetlands surrounded by a strong boundary matrix of terrestrial habitat, potentially increased the costs of leaving the wetland. The high costs of travelling overland to more distant wetlands may have constrained the translocated turtles dispersal from the release site and increased release site fidelity. Our study suggests that hard-release translocations may be an effective conservation method for highly aquatic species unlikely to leave the wetland and travel long overland distances.  相似文献   

15.
16.
Abstract: Natural and anthropogenic landscape features, such as rivers, mountain ranges, and roads can alter animal dispersal paths and movement patterns. Consequently landscape, through its effects on dispersal, may influence many ecological processes, including disease transmission, invasion dynamics, and gene flow. To investigate influences of landscape features on dispersal patterns of a large mammal, we captured and radiomarked 363 juvenile male white-tailed deer (Odocoileus virginianus), including 212 confirmed dispersers, in 2 topographically dissimilar study areas in Pennsylvania, USA. Dispersal azimuths were uniformly distributed in the western study area (WSA), where there was irregular, hilly topography. Mean dispersal azimuths paralleled ridge direction in the eastern study area, where long parallel ridges were aligned northeast-southwest. Major roads in both areas and a large river in the WSA were semipermeable barriers to dispersal of juvenile males; dispersal paths were less likely to intersect these linear features. Dispersal movements were direct and brief, typically lasting <12 hours. For all dispersers, we found no evidence for preference or avoidance of establishing adult, postdispersal ranges in proximity to roads; however, deer that encountered roads near the terminus of their dispersal path were more likely to stop on the near side. Further, for deer that established postdispersal home ranges near major roads, these features influenced range placement such that locations were typically clustered on one side of the road. The influence of roads, rivers, and mountains on dispersal paths and postdispersal locations of white-tailed deer suggest that landscape-specific features should be considered in conservation and management of this and possibly other species of large mammals.  相似文献   

17.
ABSTRACT Delineating populations is critical for understanding population dynamics and managing habitats. Our objective was to delineate subpopulations of migratory female white-tailed deer (Odocoileus virginianus) in the central Black Hills, South Dakota and Wyoming, USA, on summer and winter ranges. We used fuzzy classification to assign radiocollared deer to subpopulations based on spatial location, characterized subpopulations by trapping sites, and explored relationships among survival of subpopulations and habitat variables. In winter, Kaplan-Meier estimates for subpopulations indicated 2 groups: high (S = 0.991 ± 0.005 [x̄ ± SE]) and low (S = 0.968 ± 0.007) weekly survivorship. Survivorship increased with basal area per hectare of trees, average diameter at breast height of trees, percent cover of slash, and total point-center quarter distance of trees. Cover of grass and forbs were less for the high survivorship than the lower survivorship group. In summer, deer were spaced apart with mixed associations among subpopulations. Habitat manipulations that promote or maintain large trees (i.e., basal area = 14.8 m2/ha and average dbh of trees = 8.3 cm) would seem to improve adult survival of deer in winter.  相似文献   

18.
Camera traps are commonly used to study mammal ecology and they occasionally capture previously undocumented species interactions. The key deer (Odocoileus virginianus clavium) is an endangered endemic subspecies of the Florida Keys, where it exists with few predators. We obtained a camera trap sequence of 80 photos in which a key deer interacted with two northern raccoons (Procyon lotor). One of the raccoons groomed the deer’s face for ∼1 min. This interaction is peculiar and appears mutualistic because the deer was not concerned and willingly remained still throughout the physical contact. Although mutualistic relationships between deer and birds are common, we are unaware of any previously documented mesocarnivore-deer mutualisms. Key deer have evolved in the absence of mammalian predators and we hypothesize that they exhibit reduced vigilance or concern when encountering other species because of predator naivety. Key deer and raccoons are commonly associated with humans and urbanization and an alternative hypothesis is that the interactions are a consequence of heightened deer density, causing a greater probability of sustained interactions with the common mesocarnivores.  相似文献   

19.
Scaled quail (Callipepla squamata) decline caused by habitat loss and fragmentation increased interest in translocation to reestablish populations. Yet factors determining translocation success are poorly understood. We tested hypotheses concerning the influence of source population and variation in delayed release strategy (1–9 weeks) on mortality and dispersal of wild-caught, translocated scaled quail. We trapped and translocated quail from 2016–2017 from source populations in the Edwards Plateau and Rolling Plains ecoregions to a large contiguous (>40,000 ha) release site in Knox County, Texas, USA. We evaluated mortality and dispersal of translocated females as a function of source population, holding time prior to release, age, release location, and year using a multi-state mark-recapture model with state uncertainty. Scaled quail translocated within the Rolling Plains were more likely to exhibit philopatry to the release site. Quail with longer holding times had higher mortality but lower dispersal rates. The Edwards Plateau is a suitable source site for translocation in the Rolling Plains. The reduced dispersal but higher mortality of translocated scaled quail associated with longer holding times creates a decision tradeoff for managers.  相似文献   

20.
ABSTRACT Approximately 26% of annual mortality for the endangered Florida Key deer (Odocoileus virginianus clavium) occurs as deer-vehicle collisions (DVCs) on the 5.6-km section of United States Highway 1 (US 1) on Big Pine Key (BPK), but extensive urban development adjacent to sections of US 1 complicates efforts to reduce DVCs. Our objective was to evaluate the effectiveness of the US 1 Project (continuous 2.6-km system of 2.4-m fencing, 2 underpasses, and 4 experimental deer guards constructed on US 1 on BPK) in reducing DVCs along US 1. Deer used the underpasses all 3 postproject years (2003–2005); however, we observed higher underpass use in 2004 and 2005 compared to 2003. Exclusion fencing reduced deer intrusions onto the fenced section of US 1 during the 3-year period (2003, n = 7 deer; 2004, n = 4; 2005, n = 12). With a reduction of deer intrusions onto this section of US 1, DVCs decreased in the fenced area by 73–100%; however, US 1 DVCs within the unfenced sections of US 1 also increased (40%) as expected. In controlling for effects of increasing deer density and traffic volume, study results suggest that highway improvements have decreased the net risk of DVCs along US 1, which indicates that use of deer fencing, deer guards, and underpasses is applicable in other urban communities experiencing unacceptable levels of DVCs.  相似文献   

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