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LOUIS C. BENDER LAURIE A. LOMAS JASON BROWNING 《The Journal of wildlife management》2007,71(4):1118-1124
Abstract: From December 2001 to December 2004 we monitored 30–44 adult female mule deer (Odocoileus hemionus) annually to assess the factors affecting survival and cause-specific mortality. We found adult female survival of 0.63 (SE = 0.08), 0.90 (SE = 0.05), and 0.91 (SE = 0.04), 2002–2004, respectively. Starvation was the most common cause of mortality, accounting for 11/23 mortalities. Mean ingesta-free body fat (IFBF) levels of adult females in December were low (6–9%), despite few (0–13%) lactating adult females, indicative of extremely nutritionally deficient summer—autumn ranges throughout the study site. A priori levels of IFBF and rump body condition scores (rBCS) were higher in deer that survived the following year regardless of cause of mortality. Logistical analysis indicated that models containing individual body fat, rBCS, mean population body fat, winter precipitation, precipitation during mid- to late gestation, and total annual precipitation were related (x2 ≥ 9.1; P ≤ 0.003) to deer survival, with individual IFBF (β =-0.47 [SE = 0.21]; odds ratio = 0.63 [0.42-0.94]) and population mean IFBF (β = -1.94 [SE = 0.68]; odds ratio = 0.14 [0.04-0.54]) the best predictors; with either variable, probability of dying decreased as fat levels increased. Fawn production was low (2–29 fawns/100 ad F) and, combined with adult survival, resulted in estimated population rates of increase of -35%, -5%, and +6% for 2002–2004, respectively. Deer survival and population performance were limited in north-central New Mexico, USA, due to poor condition of deer, likely a result of limited food resulting from both drought and long-term changes in plant communities. Precipitation during mid- to late gestation was also important for adult female survival in north-central New Mexico. 相似文献
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《Ethology, Ecology and Evolution》2012,24(1):115-119
The present study investigates the prediction that, given the energy-intensive nature of male courtship and rutting behavior in mule deer, bucks will preferentially mate with those does most likely to breed successfully. Does without fawns in a given breeding season are in better physical condition and are more likely to rear fawns conceived in the current breeding season than are does with fawns. In those cases where both categories of females were present, significantly more courtship behaviors were directed towards does without fawns than towards does with fawns. The consequences of such a choice by bucks are discussed. 相似文献
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Chloe A. Wright Ian T. Adams Patrick Stent Adam T. Ford 《The Journal of wildlife management》2020,84(8):1457-1472
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
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Madelon Van de Kerk Brock R. McMillan Kent R. Hersey Annette Roug Randy T. Larsen 《The Journal of wildlife management》2020,84(4):813-820
Capture techniques to deploy radio-collars often risk mortality and injury to the animal. Capture-induced mortality can affect population sizes but also introduces bias in survival estimates based on data from captured animals. In recent years, a large-scale research and monitoring project in Utah, USA, has involved capturing and radio-collaring hundreds of mule deer (Odocoileus hemionus), a species of great interest in large parts of North America. Our objective was to investigate how the survival rates of these mule deer were affected by capture and handling. During winters of 2014–2018, an experienced capture crew net-gunned and fitted 1,805 animals with global positioning system (GPS)-collars. We estimated survival rates during the first 6 weeks after capture using Cox proportional hazard regression, and compared the survival rates of animals that were captured in a particular year to those of animals that were not captured but fitted with a GPS-collar in a previous year. We used a model selection framework to evaluate how long survival rates of captured animals were different from those of animals that were not captured. Our results indicated that weekly survival rates of captured animals were 0.985 ± 0.003 (SE), 0.988 ± 0.002, and 0.990 ± 0.001 in weeks 1, 2 and 3, respectively. Weekly survival rates of captured deer during weeks 4–6 were 0.993 ± 0.001, the same as those of deer that were not captured at the same time. Furthermore, post-capture survival rates were positively influenced by body size and negatively influenced by age. We conclude that the mortality resulting from helicopter capture was low but recommend comparing newly captured and previously captured individuals to examine what proportion of observed mortality is likely capture-related. © 2020 The Wildlife Society. 相似文献
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Roadways may pose barriers to long-distance migrators such as some ungulates. Highway underpasses mitigate wildlife-vehicle collisions and can be an important management tool for protecting migration corridors. In northern California, 3 underpasses were built on United States Route 395 (Route 395) in Hallelujah Junction Wildlife Area (HJWA) in the 1970s for a migratory mule deer (Odocoileus hemionus) herd that had been negatively affected by highway traffic. To determine whether these underpasses were still reducing mule deer mortalities >40 years after construction, we investigated deer use of the underpasses from 2006–2019 using cameras, global positioning system (GPS) collars, and roadkill records. We used occupancy models, approximations of GPS-collared mule deer movement paths, and roadkill locations to estimate the highway crossing patterns of deer. From camera data, there was higher use of the underpasses by deer during migration (spring [Mar–Jun], fall [Oct–Dec]) than in summer (Jul–Sep), when only resident deer were present. Higher underpass usage occurred in the spring compared to fall migrations. Eleven of 21 GPS-collared migrating mule deer crossed Route 395. We estimated 30% of the crossings (by 7 of the 11 deer) occurred south of the underpasses where deer could easily access the highway because of short (1-m high) and deteriorating highway fencing. Roadkill data confirmed that deer-vehicle collisions were occurring south of the underpasses and at the underpasses. This was likely due to deteriorating infrastructure at the underpasses that allows wildlife access to the highway. Overall, our study indicated that although underpasses can provide safe passage for migratory deer decades (>40 yr) after their construction, deteriorating infrastructure such as fencing and gates can lead to wildlife mortalities on highways near underpasses. © 2021 The Wildlife Society. 相似文献
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Effects of population density of mule deer Odocoileus hemionus on forage selection were investigated by comparing diet characteristics of two subpopulations of deer in southern California, USA, that differed in population density during winter. Quality of diet for deer, as indexed by faecal crude protein, was higher at the low-density site than at the high-density site in winter, when deer densities were different. Quality of diet was similar in summer when both areas had comparable densities of deer. Both outcomes are consistent with predictions from density-dependent selection of diets by deer. Dietary niche breadth, however, differed in a manner opposite to predictions of niche theory based on diet selection under an ideal-free distribution. During winter, when differences in density between the two study sites were pronounced, niche breadth along the dietary axis in the low-density area was twice that of the high-density site. Generalist herbivores feeding primarily on low-quality browse at high population density in winter would be expected to increase their dietary breadth by feeding on additional species of plants as they depleted their food supply. Mule deer in our study, however, decreased the breadth of their dietary niche as population density increased. We hypothesize that by rapidly eliminating high-quality forages from an area by heavy grazing, deer at higher population densities narrowed their dietary niche. Theoretical models for changes in niche dimensions, including the ideal-free distribution, need to consider such empirical outcomes. 相似文献
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CHAD J. BISHOP DAVID J. FREDDY GARY C. WHITE THOMAS R. STEPHENSON LISA L. WOLFE BRUCE E. WATKINS 《The Journal of wildlife management》2007,71(3):945-954
Abstract: Estimating survival of the offspring of marked female ungulates has proven difficult in free-ranging populations yet could improve our understanding of factors that limit populations. We evaluated the feasibility and efficiency of capturing large samples (i.e., >80/yr) of neonate mule deer (Odocoileus hemionus) exclusively from free-ranging, marked adult females using vaginal implant transmitters (VITs, n = 154) and repeated locations of radiocollared females without VITs. We also evaluated the effectiveness of VITs, when used in conjunction with in utero fetal counts, for obtaining direct estimates of fetal survival. During 2003 and 2004, after we placed VIT batteries on a 12-hour duty cycle to lower electronic failure rates, the proportion that shed ≤ 3 days prepartum or during parturition was 0.623 (SE = 0.0456), and the proportion of VITs shed only during parturition was 0.447 (SE = 0.0468). Our neonate capture success rate was 0.880 (SE = 0.0359) from females with VITs shed ≤ 3 days prepartum or during parturition and 0.307 (SE = 0.0235) from radiocollared females without VITs or whose implant failed to function properly. Using a combination of techniques, we captured 275 neonates and found 21 stillborns during 2002-2004. We accounted for all fetuses at birth (i.e., live or stillborn) from 78 of the 147 females (0.531, SE = 0.0413) having winter fetal counts, and this rate was heavily dependent on VIT retention success. Deer that shed VITs prepartum were larger than deer that retained VITs to parturition, indicating a need to develop variable-sized VITs that may be fitted individually to deer in the field. We demonstrated that direct estimates of fetal and neonatal survival may be obtained from previously marked female mule deer in free-ranging populations, thus expanding opportunities for conducting field experiments. Survival estimates using VITs lacked bias that is typically associated with other neonate capture techniques. However, current vaginal implant failure rates and overall expense limit broad applicability of the technique. 相似文献
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We evaluated the precision of age estimates produced by cementum annuli analysis (CAA) of blind-duplicate specimens taken from 994 southern mule deer (Odocoileus hemionus) collected over 15 years. We found that the mean annual proportion of unreliably aged incisor pairs was greater for females (0.48, SD = 0.13) than for males (0.22, SD = 0.07). Most of the 308 unreliably aged tooth pairs disagreed by only 1 year. Sex, precipitation, and certainty codes assigned by Matson's Lab to the age estimates were the best predictors for agreement of estimated ages within incisor pairs. Our estimated overall age error rate of CAA (17%) was >2 times as large as estimated error rates from Montana and South Dakota, but less than half of error rates estimated for Mississippi and south Texas. Knowing the error rate of age estimates from a specific deer population allows wildlife managers to perform tasks requiring specific age class information such as monitoring the harvest rate of older female deer in a hunted population or performing population reconstruction. © 2011 The Wildlife Society. 相似文献
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CHAD J. BISHOP GARY C. WHITE PAUL M. LUKACS 《The Journal of wildlife management》2008,72(5):1085-1093
Abstract: The assumption of independent sample units is potentially violated in survival analyses where siblings comprise a high proportion of the sample. Violation of the independence assumption causes sample data to be overdispersed relative to a binomial model, which leads to underestimates of sampling variances. A variance inflation factor, c, is therefore required to obtain appropriate estimates of variances. We evaluated overdispersion in fetal and neonatal mule deer (Odocoileus hemionus) datasets where more than half of the sample units were comprised of siblings. We developed a likelihood function for estimating fetal survival when the fates of some fetuses are unknown, and we used several variations of the binomial model to estimate neonatal survival. We compared theoretical variance estimates obtained from these analyses with empirical variance estimates obtained from data-bootstrap analyses to estimate the overdispersion parameter, c. Our estimates of c for fetal survival ranged from 0.678 to 1.118, which indicate little to no evidence of overdispersion. For neonatal survival, 3 different models indicated that ĉ ranged from 1.1 to 1.4 and averaged 1.24–1.26, providing evidence of limited overdispersion (i.e., limited sibling dependence). Our results indicate that fates of sibling mule deer fetuses and neonates may often be independent even though they have the same dam. Predation tends to act independently on sibling neonates because of dam-neonate behavioral adaptations. The effect of maternal characteristics on sibling fate dependence is less straightforward and may vary by circumstance. We recommend that future neonatal survival studies incorporate additional sampling intensity to accommodate modest overdispersion (i.e., ĉ = 1.25), which would facilitate a corresponding ĉ adjustment in a model selection analysis using quasi-likelihood without a reduction in power. Our computational approach could be used to evaluate sample unit dependence in other studies where fates of individually marked siblings are monitored. 相似文献
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HILARY S. COOLEY HUGH S. ROBINSON ROBERT B. WIELGUS CATHERINE S. LAMBERT 《The Journal of wildlife management》2008,72(1):99-106
Abstract Widespread mule deer (Odocoilus hemionous) declines coupled with white-tailed deer (O. virginianus) increases prompted us to investigate the role of cougar (Puma concolor) predation in a white-tailed deer, mule deer, and cougar community in northeast Washington, USA. We hypothesized that cougars select for and disproportionately prey on mule deer in such multiple-prey communities. We estimated relative annual and seasonal prey abundance (prey availability) and documented 60 cougar kills (prey usage) from 2002 to 2004. White-tailed deer and mule deer comprised 72% and 28% of the total large prey population and 60% and 40% of the total large prey killed, respectively. Cougars selected for mule deer on an annual basis (αmd = 0.63 vs. αwt = 0.37; P = 0.066). We also detected strong seasonal selection for mule deer with cougars killing more mule deer in summer (αmd = 0.64) but not in winter (αmd = 0.53). Cougars showed no seasonal selection for white-tailed deer despite their higher relative abundance. The mean annual kill interval of 6.68 days between kills varied little by season (winter = 7.0 days/kill, summer = 6.6 days/kill; P = 0.78) or prey species (white-tailed deer = 7.0 days/kill, mule deer = 6.1 days/kill; P = 0.58). Kill locations for both prey species occurred at higher elevations during summer months (summer = 1,090 m, winter = 908 m; P = 0.066). We suspect that cougars are primarily subsisting on abundant white-tailed deer during winter but following these deer to higher elevations as they migrate to their summer ranges, resulting in a greater spatial overlap between cougars and mule deer and disproportionate predation on mule deer. 相似文献
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Abstract: Because of significant declines in mule deer (Odocoileus hemionus) populations across New Mexico, USA, we investigated survival of fawns in north-central New Mexico, USA. We captured 19 fawns, 34 fawns, and 47 fawns in 2002, 2003, and 2004, respectively, and used fawn morphological measurements, habitat characteristics, and adult female (hereafter “female”) condition to model preweaning fawn survival. Survival was 0.0, 0.12, 0.52 for 2002, 2003, and 2004, respectively, and was related to birth mass (χ12 = 9.5, P = 0.002), birth date (χ12= 8.4, P = 0.004), litter size (χ22 = 9.4, P = 0.009), female body fat (χ12 = 40.9, P < 0.001), annual precipitation (χ12 = 35.0, P < 0.001), summer precipitation (χ12= 37.5, P < 0.001), and winter precipitation (χ12 = 32.0, P < 0.001). Total ingesta-free body fat of females (β = 3.01, SE = 0.75; odds ratio = 20.19, 95% CI = 4.64-87.91) and birth mass of fawns (β = 1.188, SE = 0.428; odds ratio = 3.38, 95% CI = 1.42-7.59) were the best predictors of survival of individual fawns, although few of the logistic models differed in model selection criteria. Fawn survival in north-central New Mexico was driven by an interaction of total and seasonal precipitation and its effect on plant production, consequential effects on female nutrition, and ultimately, fawn birth attributes. Habitat conditions were so poor throughout north-central New Mexico during 2002 and 2003 (and likely during other drought yr) that, based upon birth attributes, few fawns could have survived regardless of proximate causes of mortality. In 2004, precipitation enhanced security cover, maternal body condition, birth attributes and, thus, survival of fawns. However, more habitat enhancements are needed to improve the nutritional quality of mule deer habitats in north-central New Mexico and further enhance maternal and fawn condition to recover mule deer populations in this region. 相似文献
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Abstract: We selected 2 adjacent populations of mule deer (Odocoileus hemionus hemionus) in the Bridger Mountains, Montana, USA, to measure effects on survival rates and causes of mortality of 2 hunting regulations designed to enhance representation of mature males. We compared male survival between the West Slope and South 16 Mile populations considering both hunting and nonhunting sources of mortality with respect to age (fawn, yearling, and mature), month (Jun-May), and year (1990-1995). Harvest rates of mature males were greater than for yearlings, demonstrating hunter preferences. We found no differences in yearling monthly survival rates between October and November or between areas or years. In contrast, we found survival of mature males differed between October and November and across years and study areas. During these months, survival rates of mature males averaged 0.602 on the West Slope under the 2-point regulation and 0.762 on South 16 Mile under the outfitted hunt. Monthly survival during summer also differed by age class, but not area, with estimates of 0.963 for yearling males, and corresponding mature male survival estimates of 0.991, demonstrating greater yearling summer mortality. Winter survival rates of yearlings and matures were similar for both areas with a monthly estimate of 0.986. We found differences in spring monthly survival estimates for the 2 areas, mainly for matures. Yearling male monthly survival estimates were 0.959 and 0.958 for the 2 areas, whereas corresponding mature male estimates during spring were 0.991 and 0.936 on the West Slope and South 16 Mile, respectively. Fawn survival rates varied from 0.101 to 0.770 among years and between areas overwinter. Cumulative effects of nonhunting mortality among all age classes reduced the effectiveness of 2 hunting regulations designed to enhance survival of males to age classes ≥4 years associated with maximum antler development despite accomplishing reductions in harvest rates. Low and variable fawn survival and relatively high nonhunting-related losses of yearling and mature males might be typical of many populations in the Northern Rocky Mountains. Deer managers should avoid populations coexisting with a diversity of large predators in environments with strong year effects when considering opportunities for implementing harvest regulations to improve representation of mature males. 相似文献
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Tayler N. LaSharr Samantha P. H. Dwinnell Brittany L. Wagler Hall Sawyer Rhiannon P. Jakopak Anna C. Ortega Luke R. Wilde Matthew J. Kauffman Katey S. Huggler Patrick W. Burke Miguel Valdez Patrick Lionberger Douglas G. Brimeyer Brandon Scurlock Jill Randall Rusty C. Kaiser Mark Thonhoff Gary L. Fralick Kevin L. Monteith 《The Journal of wildlife management》2023,87(1):e22333
Capture and handling techniques for individual-based, long-term research that tracks the life history of animals by recapturing the same individuals for several years has vastly improved study inferences and our understanding of animal ecology. Yet there are corresponding risks to study animals associated with physical trauma or capture myopathy that can occur during or following capture events. Rarely has empirical evidence existed to guide decisions associated with understanding the magnitude of capture-related risks, how to reduce these risks when possible, and implications for mortality censoring and survival estimates. We used data collected from 2,399 capture events of mule deer (Odocoileus hemionus) via helicopter net-gunning to compare daily survival probabilities within a 10-week period centered on a capture event and evaluated how animal age, nutritional condition (body fat), and various handling methods influenced survival before, during, and following a capture event. Direct mortality resulting from capture efforts was 1.59%. Mean daily survival was 0.9993 ± 0.0001 (SE) during the 5-week pre-capture window, was depressed the day of capture at 0.9841 ± 0.0004, and rebounded to 0.9990 ± 0.0008 during the 5-week post-capture window. Neither capture nor handling had a detectable effect on post-capture survival, including handling time (
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Daniel W. Sallee Brock R. McMillan Kent R. Hersey Steven L. Petersen Randy T. Larsen 《The Journal of wildlife management》2023,87(1):e22318
Ungulates often alter behavior and space use in response to interspecific competition. Despite observable changes in behavior caused by competitive interactions, research describing the effects of competition on survival or growth is lacking. We used spatial modeling to determine if habitat use by female mule deer (Odocoileus hemionus) was affected by other ungulate species prior to, during, and after parturition. We conducted our study in the Book Cliffs region of eastern Utah, USA, during 2019 and 2020. We used resource selection function (RSF) analysis to model space use of 4 ungulate species that potentially competed with mule deer: bison (Bos bison), cattle, elk (Cervus canadensis), and feral horses. We incorporated RSF models for competing species into a random forest analysis to determine if space use by mule deer was influenced by these other ungulate species. We used survival and growth data from neonate mule deer to directly assess potential negative effects of other ungulates. Habitat use by elk was an important variable in predicting use locations of mule deer during birthing and rearing. The relationship was positive, suggesting interference competition was not occurring. Survival of neonate mule deer increased as the probability of use by elk increased (hazard ratio = 0.185 ± 0.497 [SE]). Further, probability of use by elk in rearing habitat had no influence on growth of neonate mule deer from birth to 6 months of age, suggesting that exploitative competition was not occurring. 相似文献
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Casey L. Brown Joshua B. Smith Michael J. Wisdom Mary M. Rowland Derek B. Spitz Darren A. Clark 《The Journal of wildlife management》2020,84(7):1246-1255
Mule deer (Odocoileus hemionus) are widely hunted throughout western North America and are experiencing population declines across much of their range. Consequently, understanding the direct and indirect effects of hunting is important for management of mule deer populations. Managers can influence deer mortality rates through changes in hunting season length or authorized tag numbers. Little is known, however, about how hunting can affect site fidelity patterns and subsequent habitat use and movement patterns of mule deer. Understanding these patterns is especially important for adult females because changes in behavior may influence their ability to acquire resources and ultimately affect their productivity. Between 2008 and 2013, we obtained global positioning system locations for 42 adult female deer at the Starkey Experimental Forest and Range in northeast Oregon, USA, during 5-day control and treatment periods in which hunters were absent (pre-hunt), present but not actively hunting (scout and post-hunt), and actively hunting male mule deer (hunt) on the landscape. We estimated summer home ranges and 5-day use areas during pre-hunt and hunt periods and calculated overlap metrics across home ranges and use areas to assess site fidelity within and across years. We used step selection functions to evaluate whether female mule deer responded to human hunters by adjusting fine-scale habitat selection and movement patterns during the hunting season compared to the pre-hunt period. Mule deer maintained site fidelity despite disturbance by hunters with 72 ± 4% (SE) within-year overlap between summer home ranges and hunt use areas and 54 ± 7% inter-annual overlap among pre-hunt use areas and 56 ± 7% among hunt use areas. Mule deer diurnal movement rates, when hunters are active on the landscape, were higher during the hunting period versus pre-hunt or scout periods. In contrast, nocturnal movement rates, when hunters are inactive on the landscape, were similar between hunting and non-hunting periods. Additionally, during the hunt, female mule deer hourly movements increased in areas with high greenness values, indicating that mule deer spent less time in areas with more vegetative productivity. Female mule deer maintained consistent habitat selection patterns before and during hunts, selecting areas that offered more forest canopy cover and high levels of vegetative productivity. Our results indicate that deer at Starkey are adopting behavioral strategies in response to hunters by increasing their movement rates and selecting habitat in well-established ranges. Therefore, considering site fidelity behavior in management planning could provide important information about the spatial behavior of animals and potential energetic costs incurred, especially by non-target animals during hunting season. © 2020 The Wildlife Society. 相似文献