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1.
Troy W. Grovenburg Robert W. Klaver Jonathan A. Jenks 《The Journal of wildlife management》2012,76(5):944-956
Environmental factors, such as forest characteristics, have been linked to fawn survival in eastern and southern white-tailed deer (Odocoileus virginianus) populations. In the Great Plains, less is known about how intrinsic and habitat factors influence fawn survival. During 2007–2009, we captured and radiocollared 81 fawns in north-central South Dakota and recorded 23 mortalities, of which 18 died before 1 September. Predation accounted for 52.2% of mortality; remaining mortality included human (hunting, vehicle, and farm accident; 26.1%) and hypothermia (21.7%). Coyotes (Canis latrans) accounted for 83.3% of predation on fawns. We used known-fate analysis in Program MARK to estimate summer (15 May–31 Aug) survival rates and investigated the influence of intrinsic and habitat variables on survival. We developed 2 a priori model sets, including intrinsic variables and a test of annual variation in survival (model set 1) and habitat variables (model set 2). Model set 1 indicated that summer survival varied among years (2007–2009); annual survival rates were 0.94 (SE = 0.06, n = 22), 0.78 (SE = 0.09, n = 27), and 0.54 (SE = 0.10, n = 32), respectively. Model set 2 indicated that survival was further influenced by patch density of cover habitats (Conservation Reserve Program [CRP]-grasslands, forested cover, and wetlands). Mean CRP-grassland and wetland patch density (no. patches/100 ha) were greater (P < 0.001) in home-range areas of surviving fawns ( = 1.81, SE = 0.10, n = 63; = 1.75, SE = 0.14, n = 63, respectively) than in home-range areas of fawns that died ( = 0.16, SE = 0.04, n = 18; = 1.28, SE = 0.10, n = 18, respectively). Mean forested cover patch density was less (P < 0.001) in home-range areas of surviving fawns ( = 0.77, SE = 0.10, n = 63) than in home-range areas of fawns that died ( = 1.49, SE = 0.21, n = 18). Our results indicate that management activities should focus on CRP-grassland and wetland habitats in order to maintain or improve fawn survival in the northern Great Plains, rather than forested cover composed primarily of tree plantings and shelterbelts. © 2012 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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TROY W. GROVENBURG CHRISTOPHER N. JACQUES ROBERT W. KLAVER JONATHAN A. JENKS 《The Journal of wildlife management》2010,74(6):1250-1256
Abstract: Bed site selection is an important behavioral trait influencing neonate survival. Vegetation characteristics of bed sites influence thermal protection of neonates and concealment from predators. Although previous studies describe bed site selection of neonatal white-tailed deer (Odocoileus virginianus) in regions of forested cover, none determined microhabitat effects on neonate bed site selection in the Northern Great Plains, an area of limited forest cover. During summers 2007–2009, we investigated bed site selection (n = 152) by 81 radiocollared neonate white-tailed deer in north-central South Dakota, USA. We documented 80 (52.6%) bed sites in tallgrass-Conservation Reserve Program lands, 35 (23.0%) bed sites in forested cover, and 37 (24.3%) in other habitats (e.g., pasture, alfalfa, wheat). Bed site selection varied with age and sex of neonate. Tree canopy cover (P < 0.001) and tree basal area (P < 0.001) decreased with age of neonates, with no bed sites observed in forested cover after 18 days of age. Male neonates selected sites with less grass cover (P < 0.001), vertical height of understory vegetation (P < 0.001), and density of understory vegetation (P < 0.001) but greater bare ground (P = 0.047), litter (P = 0.028), and wheat (P = 0.044) than did females. Odds of bed site selection increased 3.5% (odds ratio = 1.035, 95% CI = 1.008–1.062) for every 1-cm increase in vertical height of understory vegetation. Management for habitat throughout the grasslands of South Dakota that maximizes vertical height of understory vegetation would enhance cover characteristics selected by neonates. 相似文献
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CHRISTOPHER S. ROSENBERRY ERIC S. LONG HEATHER M. HASSEL-FINNEGAN VINCENT P. BUONACCORSI DUANE R. DIEFENBACH BRET D. WALLINGFORD 《The Journal of wildlife management》2009,73(3):357-361
ABSTRACT Behavioral studies of white-tailed deer (Odocoileus virginianus) often assign mother-offspring relationships based on common capture of juveniles with adult deer, assuming that fawns associate closely with mothers. We tested this assumption using genetic parentage to assess mother-offspring relationships within capture groups based on data from 10 polymorphic microsatellite loci. At the 80% confidence level, we assigned maternity to 43% and 51% of juveniles captured with an adult female in 2 respective study areas. Capture with their mother did not differ by sex of juveniles in either study area, and limiting our analysis to capture groups that most represent family groups (i.e., one ad F with 1–3 juv) did not increase maternity assignment (35%). Our results indicate that common capture may be a poor indicator of mother-offspring relationships in many field settings. We recommend genetic verification of family relationships. 相似文献
6.
STEPHEN L. WEBB JOHN S. LEWIS DAVID G. HEWITT MICKEY W. HELLICKSON FRED C. BRYANT 《The Journal of wildlife management》2008,72(1):310-314
Abstract The helicopter and net gun is a technique used to capture white-tailed deer (Odocoileus virginianus) and is useful in a variety of habitat types and at various population densities with the ability to be highly selective. During capture, deer may sustain injuries or even die as a result of capture and handling, and may also be prone to capture myopathy. Therefore, our objectives were to determine 1) type and frequency of injuries sustained during the helicopter and net-gun capture, and 2) the effects of capture on survival of radiocollared deer. We captured 3,350 white-tailed deer from 1998 to 2005 using a net gun fired from a helicopter on 5 southern Texas, USA, ranches. Additionally, we captured 51 yearling males and 49 mature (≥4 yr of age) males and fitted them with radiocollars to monitor their survival. We recorded injuries and mortalities during capture and ranked the seriousness of injuries on a scale from 0 to 4. We recorded 281 injuries (8.4%) and as a result of capture, at least 206 deer had broken antlers (6.1%), 55 were injured (1.6%), and 20 were direct mortalities (0.6%). The most common antler injury was broken antler tines and the most common body injury was broken legs. Postcapture mortality rates were low (1%) for this capture method. Based on capture-related injuries, mortalities, and postcapture survival, we found the helicopter and net gun to be a safe capture technique compared to other capture techniques, particularly when conditions are favorable. 相似文献
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STEPHEN L. WEBB DAVID G. HEWITT MICKEY W. HELLICKSON 《The Journal of wildlife management》2007,71(2):555-558
ABSTRACT Understanding sources of male deer mortality is a prerequisite to a successful management program, especially in Texas, USA, where white-tailed deer (Odocoileus virginianus) are the most economically important game species. South Texas, USA, is one of the few areas where males reach older age classes (> 4.5 yr), in part because of intense population management. Therefore, we obtained survival rates and causes of mortality of 48 mature male deer in south Texas, USA, over 2 years. We calculated Kaplan—Meier survival estimates during 2 study years modified for a staggered-entry design and annual survival rates for one cohort of deer from 1998 to 2004 using recapture and radiotelemetry data. We documented 21 mortalities (16 harvest and 5 nonhunting mortalities). Average annual survival of the known-aged 1998 cohort was 82% with 52% of surviving to 6.5 years of age. Survival in study year 2 (0.497 ± 0.069) was less than in study year 1 (0.781 ± 0.073; P = 0.0047), largely because males had finally reached harvestable age (> 6.5 yr old). All but one non-harvest mortality occurred during the rut or postrut periods. It appears that a large percentage of males can reach mature age classes under intense population management, making them available for harvest when at peak antler size. This allows for increased economic returns on intensively managed white-tailed deer populations. 相似文献
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Abstract: Past studies using penned deer provide conflicting results on the age when reliable predictions about antler growth potential in white-tailed deer (Odocoileus virginianus) can be made. We captured wild whitetail males via aerial net gun on 12 ranches in 5 counties in south Texas, USA, from 1999 to 2007 to determine if a reliable juvenile-to-adult relationship in antler development existed. We individually marked and released captured animals at the trap site after we took antler and body measurements. We recaptured marked animals as possible in subsequent years or until we obtained final measurements after legal harvest. Amount of growth in the first set of antlers in whitetail males was a poor predictor of antler growth at maturity. By 4.5 years of age there were no differences (P > 0.05) in antler measurements regardless of the amount of development of the first set of antlers at 1.5 years. We concluded culling of yearling males based on number of antler points would have little positive effect on overall antler quality in future years. 相似文献
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ABSTRACT Demarais and Strickland presented several questions about the scope and validity of conclusions regarding predictability of mature antler size based on yearling antler size and produced a simulation model reported to demonstrate measurement bias in our 2008 study. We believe our conclusions were appropriate with our research hypothesis and demonstrated the assumed differential selection bias by hunters used in Demarais and Strickland was unwarranted. Demarais and Strickland provided no metadata to document the provenance of data used in their model and did not account for location, year, cohort, nutrition of research animals, or loss of individuals from their sample population by accidents or death: the same questions raised in their critique. Additionally, selection and experimental design problems in a portion of their sample population indicate their model results are questionable. Our responses to Demarais and Strickland will aid wildlife managers in making future culling decisions in white-tailed deer management. 相似文献
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Sharpshooting is a proven management technique to lower white-tailed deer (Odocoileus virginianus) densities in areas where hunting is precluded. A donation program that allows for the consumptive use of these culled deer is often necessary to gain public approval for such a program. We culled 40 deer in Indiana using sharpshooting methods (head and neck shot placement) and radiographed the carcasses to determine if lead fragmentation spread throughout the skeletal muscle system. In 30 deer where shot placement was between the cranium and fourth cervical vertebrae, we observed no lead fragments in any thoracic or crural muscle tissue. Of 10 deer where shot placement was between the fifth and seventh cervical vertebrae, 8 deer experienced lead fragments in the extensor spinae muscle. Deer culled with highly frangible bullets via sharpshooting in the cranium or upper cervical spine have minimal risk of experiencing lead fragmentation in the thoracic or crural muscle systems. Deer shot in the lower neck may experience lead fragmentation in the anterior extensor spinae muscle, and up to 40 cm of that muscle should be removed before consumption. © 2011 The Wildlife Society. 相似文献
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Christopher N. Jacques Timothy R. van Deelen Wayne H. Hall Jr. Karl J. Martin Kurt C. Vercauteren 《The Journal of wildlife management》2011,75(1):221-231
Fates of individuals outfitted with radiotransmitters commonly are used for estimating survival rates in populations of large animals that are hunted. Despite precautions, this practice may be subject to complex biases associated with hunter reaction to presence of radiotransmitters. To assess this potential bias we conducted an experiment using artificial deer (i.e., decoys) to measure hunters' abilities to see deer and determine if deer seen were wearing radiocollars. We used logistic regression to quantify probabilities that seeing deer and subsequently seeing radiocollars might be influenced by distance, percent visual obstruction, body orientation, hunter experience, and antler characteristics of deer. Additionally, we evaluated how experience and antler characteristics of deer might influence a hunter's decision to harvest a radiocollared deer. We found that 25.8% of the potentially observable collared deer (n = 663) were subsequently observed by hunters. Odds of observing deer and radiocollars increased 95% and 230%, respectively, for each additional log(yr) of hunting experience. Willingness to harvest radiocollared deer increased 89% for each additional log(yr) of hunting experience and 144% for large-antlered deer relative to antlerless deer. When hunting is an important source of mortality, analysts need to understand how potential biases associated with observing deer are associated with hunters' reactions to and subsequent decisions to harvest radiocollared animals. Our study suggested that presence of radiocollars may influence a deer's potential risk of being harvested and in turn bias telemetry-based estimates of survival, given that hunting mortality is the largest component of total mortality in hunted deer populations. Collar-based telemetry is used nearly universally by wildlife managers and researchers throughout North America and elsewhere to estimate and monitor the survival of big game populations that are managed through hunting. Our findings demonstrate that these estimates are likely subject to complex and systematic biases that managers should consider when evaluating future population-level effects of managed hunting. © 2011 The Wildlife Society 相似文献
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MEREDITH A. BARRETT SABRINA MORANO GLENN D. DELGIUDICE JOHN FIEBERG 《The Journal of wildlife management》2008,72(2):555-560
ABSTRACT Wildlife management and research have depended upon trapping as an essential tool for decades. Although deer (Odocoileus spp.) capture by Clover traps remains a basic technique that has changed little over time, researchers use it as an integral part of field operations to support increasingly sophisticated and costly project objectives. Despite reports of deer preference for certain baits, no study has determined if bait preference can effectively increase capture success of free-ranging deer. By supplementing corn bait with salt, peanut butter, or molasses, we tested effects of these bait treatments on capture success of free-ranging white-tailed deer (O. virginianus), as well as levels of nontarget animal disturbance in Clover traps, during February-March 2005. With 1,446 adjusted trap-nights and a 6.5% capture success rate, the probability of capture increased over time and varied among 4 study sites (df = 3, P < 0.005); however, we did not detect a significant effect of bait supplementation on capture success (df = 3, P > 0.8). Nontarget animal activity in the trap varied by site (df = 3, P < 0.001), bait treatment (df = 3, P=0.04), and Julian date (df=3, P < 0.001). Our results are the first to suggest that bait preference may not translate into actual improved capture success of free-ranging deer. Future research should focus on testing additional baits or bait supplements to determine if an increase in trapping success and a minimization of trap disturbance by nontarget species occurs. 相似文献
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ABSTRACT Debate within the popular and technical literature regarding predictability of antler size at maturity based on 1.5-year antler size in white-tailed deer (Odocoileus virginianus) has led to confusion and uncertainty within constituent groups. Koerth and Kroll (2008) provided measures of age-related antler development using recaptures of known-age males from 12 deer populations in southern Texas. Several design and analysis issues reduce the scope and validity of their conclusion that amount of growth in the first set of antlers was a poor predictor of antler growth at maturity. Although unstated, the statistical hypothesis they tested did not coincide with their specific conclusions. Using a simulation, we show that their methods were susceptible to measurement bias. Their results are applicable only to populations with similar culling and management programs. Additionally, we provide recommendations for future research projects that evaluate predictability of antler size at maturity based on antler size at younger ages. 相似文献
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Abstract: The scale at which populations use the landscape influences ecological processes and management decisions. Dispersal and home-range size define the scale of landscape use for many large-mammal species. We measured dispersal and home-range size of yearling male white-tailed deer (Odocoileus virginianus) in southern Texas, and compared our results to values from the literature to understand the implications of dispersal in management of deer populations. We used radiotelemetry to monitor 22 yearling deer on 1 study site from October 1998 to October 1999, and 27 yearling deer on a second study site from October 1999 to October 2000. On the 2 study sites, 68% and 44% of yearling deer established new areas of use 4.4 ± 1.0 km and 8.2 ± 4.3 km, respectively, from the center of their autumn home range. Yearling males with spike antlers (2 points) were less likely to disperse than yearlings with fork antlers (>2 points) on 1 study site. Computer simulation showed that the scale at which deer use the landscape is large compared to property sizes in southern Texas and probably in other areas of the white-tailed deer's range. Differences in scale between land ownership patterns and landscape use by deer may result in a failure to meet management objectives and conflict among managers. High harvest rates for male deer occur in part because deer movements are large relative to property size, creating a “tragedy of the commons.” Cooperative management groups are beneficial if all landowners in an area agree on management objectives. Otherwise, deer-proof fences often are erected to reduce conflicts among property owners. 相似文献
15.
Jameson Mori;William Brown;Daniel Skinner;Peter Schlichting;Jan Novakofski;Nohra Mateus-Pinilla; 《Ecology and evolution》2024,14(11):e70487
White-tailed deer (Odocoileus virginianus) are a cervid species found mostly in the Americas. Managing white-tailed deer requires understanding their relationship with the environment, which was characterized by Roseberry and Woolf (Wildlife Society Bulletin 1, 1998, 252) for all counties in Illinois, USA, who incorporated habitat quantity and quality in a deer habitat suitability index. However, this index was based on satellite imagery from 1996 and did not explore the smaller spatial scales used by deer. Our study addressed these gaps by developing a deer land cover utility (LCU) score for each TRS (township, range, and section), township, and county in Illinois based on the methodology outlined in Roseberry and Woolf (Wildlife Society Bulletin 1, 1998, 252) but using data from the National Land Cover Database (2001–2021). These deer LCU scores were validated against minimum deer population data using Bayesian regression with additional covariates relevant to hunting and deer density. These models performed well with Bayesian R2 values of 0.501 (TRS), 0.5 (township), and 0.969 (county). The regression coefficients for the deer LCU scores were statistically significant (95% credibility interval not containing 0) and positive at the TRS, township, and county levels, reflecting the expected relationship between minimum deer density and deer LCU. Predictions made by these regression models on new data were accurate, with the median absolute difference between the true and predicted values being 0.398 deer/km2 for TRS', 0.085 deer/km2 for townships, and 0.066 deer/km2 for counties. This deer LCU could be used in other studies about deer in Illinois or studies in which deer are a relevant factor such as investigations about deer disease or tick distribution. This modeling approach could also be adapted to different wild species, locations, and/or time periods for which land cover data is available. 相似文献
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Andrew S. Norton Duane R. Diefenbach Bret D. Wallingford Christopher S. Rosenberry 《The Journal of wildlife management》2012,76(1):136-143
The performance of 2 popular methods that use age-at-harvest data to estimate abundance of white-tailed deer is contingent on assumptions about variation in estimates of subadult (1.5 yr old) and adult (≥2.5 yr old) male harvest rates. Auxiliary data (e.g., estimates of survival or harvest rates from radiocollared animals) can be used to relax some assumptions, but unless these population parameters exhibit limited temporal or spatial variation, these auxiliary data may not improve accuracy. Unfortunately maintaining sufficient sample sizes of radiocollared deer for parameter estimation in every wildlife management unit (WMU) is not feasible for most state agencies. We monitored the fates of 397 subadult and 225 adult male white-tailed deer across 4 WMUs from 2002 to 2008 using radio telemetry. We investigated spatial and temporal variation in harvest rates and investigated covariates related to the patterns observed. We found that most variation in harvest rates was explained spatially and that adult harvest rates (0.36–0.69) were more variable among study areas than subadult harvest rates (0.26–0.42). We found that hunter effort during the archery and firearms season best explained variation in harvest rates of adult males among WMUs, whereas hunter effort during only the firearms season best explained harvest rates for subadult males. From a population estimation perspective, it is advantageous that most variation was spatial and explained by a readily obtained covariate (hunter effort). However, harvest rates may vary if hunting regulations or hunter behavior change, requiring additional field studies to obtain accurate estimates of harvest rates. © 2011 The Wildlife Society. 相似文献
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JOSHUA J. MILLSPAUGH JOHN R. SKALSKI RICHARD L. TOWNSEND DUANE R. DIEFENBACH MARK S. BOYCE LONNIE P. HANSEN KENT KAMMERMEYER 《The Journal of wildlife management》2009,73(3):442-451
ABSTRACT The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and λ > 1, the SAK model underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to model violations and scale of analysis. Without changes to model formulation, the SAK model will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments. 相似文献
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R. TUCKER GILMAN NANCY E. MATHEWS BLAIRE G. SKINNER VICKI L. JULIS ELIZABETH S. FRANK JOANNE PAUL-MURPHY 《The Journal of wildlife management》2010,74(7):1484-1491
Abstract: Surgical sterilization by tubal ligation has been proposed as a technique for controlling white-tailed deer (Odocoileus virginianus) populations in urban or suburban areas where other forms of population control are impractical, but little is known about demographic rates in populations under management with surgical sterilization. We analyzed seasonal movement and mortality data collected during a 4-year study of surgical sterilization in suburban Chicago, Illinois, USA. We calculated 323 home range size estimates for 62 individual females within season and year. Non-gravid females without young exhibited home range sizes 52% larger than gravid females and females with fawns. Mortality rate was positively correlated with home range size. We suggest that the increased mortality rate observed in surgically sterilized females may be due to greater movement by non-maternal females. Population managers will need to account for potential effects of maternal status on movement and mortality when considering the use of sterilization for management of suburban populations of white-tailed deer. 相似文献