Number Of Deer Research Articles

Genetic Population Structure of Sika Deer, Cervus nippon, Derived from Multiple Origins, Around Toyama Prefecture of Japan.

Recently, expansion of the number and distribution of sika deer, Cervus nippon, in the Japanese Archipelago has resulted in the disturbance of indigenous gene pools and ecosystems. There are also concerns that the artificial introduction of sika deer to certain areas may aggravate this situation. In order to contribute to the conservation of ecosystems, I examined the current state of genetic disturbance and dispersal routes in the sika deer populations around Toyama Prefecture, one of the main areas of expanding sika deer distribution. Of 12 haplotypes detected by mitochondrial DNA D-loop sequence analysis, 10 were found to belong to a previously detected sika deer group in northern Japan, although the remaining two haplotypes corresponded to the southern Japanese sika deer group. The latter two haplotypes were detected at especially high frequencies in the southern area of Toyama Prefecture, suggesting that these haplotypes may derive from artificially introduced individuals. Occurrence patterns of indigenous haplotypes around Toyama Prefecture revealed immigration into Toyama Prefecture through different routes, mainly in the east and south-west. The genetic results presented here may have application in predicting future dispersal routes, as well as aid in the establishment of effective measures for management of sika deer.

Study of Nutrition Content Food Drop in Deer in PT. Gunung Madu Plantations

Increasing the number of individual deer in captivity indicates an increase in the deer population. One of the factors affecting the increase in the deer population is a drop in the quality of feed and nutritional value adequate for deer. Therefore it is necessary to investigate the type of feed and feed nutrient content in captive deer drop in PT Gunung Madu Plantations (GMP). Nutrient content of feed drop in deer obtained through the proximate analysis by taking a sample of 100 grams per sample feed. This type of feed given drop in manager consists of the main feed forage consisting of grass and leaves, in the form of rice bran concentrate feed, and feed the tubers were given every month. Based on proximate analysis that has been made known that the feed drop-in provided by the organizer captivity contains good nutrition, as seen in the high water content, extract ingredients without nitrogen (BETN) high, protein and fibers that do not differ greatly in value and fat content is not excessive. Keywords: Drop in Feed Nutrition, Feeding Deer, Captive Deer PT. GMP

Using Distance-sampling to Estimate Density of White-tailed Deer in Forested, Mountainous Landscapes in Virginia

Abstract Although Odocoileus virginianus (White-tailed Deer, hereafter, Deer) are abundant on private lands throughout much of the western Virginia mountain region, populations are comparatively low on publicly owned lands in this area. Concerns voiced by sportsmen regarding declining numbers of Deer on public lands in western Virginia prompted research to estimate the population density in selected areas within this region. From January 2012 through April 2013, we used ground-based transect sampling with forward-looking infrared (FLIR) techniques in a distance-sampling framework to estimate seasonal Deer density in mountainous western Virginia. We included habitat variables and abiotic factors thought to influence detection and ranked models using AICc model selection in the program DISTANCE. We observed 430 groups of Deer (mean group size = 2.9) during 5 sampling sessions conducted along 562.5 km traveled in Bath County, versus 102 groups (mean group size = 2.6) along 643.6 km in Rockingham County. Wind...

Linking annual variations of roe deer bag records to large-scale winter conditions: spatio-temporal development in Europe between 1961 and 2013

Synchrony in bag records over large spatio-temporal scales point to factors acting simultaneously on population size. In this manuscript, we analysed time series of annual roe deer (Capreolus capreolus) bag records for 17 European countries for the time span 1961–2013. Even though a synchronous increase in bag records was identified in 14 of 17 countries between 1986 and 1992, bag records were not synchronised at the European level. We detected a significant positive correlation between the North Atlantic Oscillation winter index (December–March) and annual changes in roe deer bag records for Czech Republic, Germany, Latvia, Lithuania, Norway and Sweden. Further time-series analyses revealed a significant lag length (L) in 13 of 17 time series on roe deer bag records which highlights that the number of bagged deer in year t was significantly correlated to the number of bagged deer in year t + L (negative association). We conclude that large-scale environmental variations or human-induced changes will not only induce periodic fluctuations in wildlife populations but also in wildlife harvest. By incorporating the knowledge about population dynamics of large herbivores into management concepts, wildlife management will not only decrease the chances of serious pitfalls but also optimise measures for population control and conservation.

Long-term population dynamics of the red deer and European roe deer at the protected and not-protected areas in Mountain Crimea

<p>The long-term population dynamics of the red deer (<em>Cervus elaphus</em> L.) and European roe deer (<em>Capreolus</em> <em>capreolus</em> L.) at the mountain and forest zone of Crimea during 1980-2017 is presented. Fluctuations in numbers of both species are cyclical and partly synchronous. Period of oscillations in the population of red deer is about 25 years, the average duration of the oscillation period of number of roe deer is 12.3 years. During the fluctuations in the number the increasing and fall in population number of the red deer had been as 26-47 %, and roe deer – as 22-34 %. Basing on the dada obtained we have assumed that together with large-scale cycles of fluctuations in population number of both red deer and roe deer the short cycles of fluctuations in the number of these species with period from 3.5 to 7.5 years take place. Significant differences of the parameters of cyclical fluctuations in the number of roe deer at some sites of the Mountainous Crimea: breaches of synchronicity, as well as significant differences in the duration of cycles are revealed. The greatest deviations from the average values of parameters of long-term dynamics of the number of roe deer in Crimea are noted for groups of this species at two protected areas. At the Crimean Nature Reserve the cycle time of fluctuations of the numbers of roe deer was 18 years. At the Karadag Nature Reserve since 1976 we can see an exponential growth in number of roe deer that is continued up to the present time. By 2016 the number of roe deer reached 750 individuals at a density of 437 animals per 1 thousand ha. Peculiarity of dynamics of number of roe deer at some sites proves the existence in the mountain forest of Crimea several relatively isolated groups of deer. We assumed that "island" location of the Crimean populations of red deer and European roe deer, their relatively little number and influence of permanent extreme factors of both natural and anthropogenic origination have contributed to a mechanism of survival of these populations. The elements of such a mechanism include the following features of long-term dynamics of the population: the reduction in the period of cyclic population fluctuations, while maintaining their amplitude and the appearance of additional small cycles, providing more flexible response of the population to the impact of both negative and positive environmental factors. From the totality of the weather conditions for the Crimean population of roe deer the recurring periods of increases and downs in the annual precipitation amount may have relevance. There was a trend of increase in the roe deer population during periods of increasing annual precipitation.</p>

Pumas affect elk dynamics in absence of other large carnivores

ABSTRACTWe investigated survival, reproduction, and population growth (λ) for a declining elk (Cervus canadensis nelsoni) population in South Dakota, USA, 2011–2015. We obtained survival data from 125 calves and 34 yearlings. We determined survival and pregnancy rates for 42 adults (2–8 years old) and 39 old adults (≥8 years old). We combined population vital rates into a matrix model, which indicated a slightly growing population but with considerable uncertainty ( = 1.03, 95% CI = 0.93–1.13). Our elasticity analysis suggested asymptotic growth rates were most sensitive to proportional changes in old adult and adult female survival, followed by proportional changes in calf and yearling survival. Our life‐stage simulation analysis further supported asymptotic growth rates being most sensitive to variation in survival, and most of the variation in λ we observed was a consequence of variation in annual calf survival (R2 = 0.58). Annual calf survival was low (0.26, 95% CI = 0.05–0.52), and puma (Puma concolor) predation was the primary cause‐specific mortality factor of calves (0.63, 95% CI = 0.51–0.76). Adult female survival was near its biological maximum (0.95, 95% CI = 0.87–0.99); therefore, managing for increased calf survival may be the most practical strategy for promoting elk population growth in this system. Managing this puma population at the lower end of the population objective and reducing white‐tailed deer (Odocoileous virginianus) numbers (primary prey source) may allow for elk population growth in this system. © 2017 The Wildlife Society.

Population dynamics affect the capacity of species distribution models to predict species abundance on a local scale

AbstractAimSpecies distribution models based on occurrence data (SDM) are used to derive broad‐scale estimates of relative abundance, but a triangular relationship between predicted suitability for species occurrence and abundance is commonly observed—that is, a low suitability would correspond to low abundances, whereas a high suitability would correspond to either low or high abundances. To properly understand the factors behind this triangular relationship, we assessed: (1) the capacity of SDM to explain variations in population abundance, and (2) the effect of population growth in the dynamics on the triangular relationship by comparing its variation in two sampling periods in the case of a species that is increasing in numbers.LocationMainland Spain.MethodsData on roe deer (Capreolus capreolus) relative abundance were obtained for 441 localities, of which 145 were surveyed twice (2006–2007 and 2011–2013). Species distribution was modelled using the favourability function. The relationship between favourability values for species occurrence and abundances were explored using quantile regressions.ResultsThe number of roe deer is increasing on a regional scale. The results from the earlier survey showed a weaker relationship than those obtained from the survey carried out later. Growth rates were significantly related to the residuals of the quantile regression fitted to the earlier survey (the higher the residual difference between observed and expected abundances, the higher the population growth rates).Main conclusionsOur results support the use of the residuals of the quantile regression as a proxy of the population growth rate. They also partly support the interpretation of the upper limit of abundance delimited by the regression as the environmental carrying capacity. Overall, the results are of general interest when using SDM to predict the population abundance of expanding species, such as alien species and/or in changing environments.

Forest management and hunting in areas adjacent to national parks: the example of the Magura National Park

Abstract the aim of the study was to evaluate arguments for hunting and its impact on forest management and conservation in national parks as well as areas directly adjacent to them. the issue was examined using the example of the Magura national Park (MnP) for which data on the number of deer and predatory mammals included in the statistical yearbooks for 2013-2014 were available. the quality and size of the food sources provided by this type of forest habitat were evaluated using data obtained from the literature. We also included data on the dietary habits of wolves and lynxes as well as their impact on the number of large ungulates in our analysis. the maximum carrying capacity of forest stands in the Magura national Park was determined to be 789 deer units (dear unit = 1 red deer or 0.3 elk or 5 roe deer), whereas in fact in 2014, the abundance of ungulates reached a total of 1230 deer units. our analysis evaluating the impact of wolf and lynx populations on ungulates in the area showed that these predators can kill up to 212 deer per year (140 individuals by wolves and 72 by lynxes). the growth in deer population, however, varies from 25.8% to 27.7%, which in the MnP amounts to 258-277 new born individuals per year, meaning that the wolf and lynx populations in the MnP are not able to prevent the number of deer from growing. the current population of ungulates (1230 deer units ) having reached a density of 6.6 deer units/km2 exceeds the capacity of the MnP and thus poses a real threat to maintaining both, the nature of the park and the adjacent stands. this article shows that the natural maintenance of balance in the predator-prey relationship is unlikely under these conditions and failure to allow for anthropogenic interference to regulate the number of ungulates in protected areas may result in an increase in the density of their population. Potential destruction of other valuable assets such as forest habitats may consequently follow. the current population of ungulates (1,230 deer units) having reached a density of 6.6 deer units/km2 exceeds the capacity of the MnP and thus poses a real threat to maintaining the nature of both the park and the adjacent stands. this article shows that the natural maintenance of balance in the predator-prey relationship is unlikely under these conditions and failure to allow for anthropogenic interference to regulate the number of ungulates in protected areas may result in an increase in the density of their population. Potential destruction of other valuable assets such as forest habitats may consequently follow.

Efficacy of N-mixture models for surveying and monitoring white-tailed deer populations

Automated cameras have become increasingly common for monitoring wildlife populations and estimating abundance. Most analytical methods, however, fail to account for incomplete and variable detection probabilities, which biases abundance estimates. Methods which do account for detection have not been thoroughly tested, and those that have been tested were compared to other methods of abundance estimation. The goal of this study was to evaluate the accuracy and effectiveness of the N-mixture method, which explicitly incorporates detection probability, to monitor white-tailed deer (Odocoileus virginianus) by using camera surveys and a known, marked population to collect data and estimate abundance. Motion-triggered camera surveys were conducted at Auburn University’s deer research facility in 2010. Abundance estimates were generated using N-mixture models and compared to the known number of marked deer in the population. We compared abundance estimates generated from a decreasing number of survey days used in analysis and by time periods (DAY, NIGHT, SUNRISE, SUNSET, CREPUSCULAR, ALL TIMES). Accurate abundance estimates were generated using 24 h of data and nighttime only data. Accuracy of abundance estimates increased with increasing number of survey days until day 5, and there was no improvement with additional data. This suggests that, for our system, 5-day camera surveys conducted at night were adequate for abundance estimation and population monitoring. Further, our study demonstrates that camera surveys and N-mixture models may be a highly effective method for estimation and monitoring of ungulate populations.

Molecular characterization of Fasciola flukes obtained from wild sika deer and domestic cattle in Hokkaido, Japan

The number of wild sika deer (Cervus nippon yesoensis) continues to increase in Hokkaido Prefecture, Japan. The major concern for the livestock industry is the transmission of pathogens between sika deer and cattle. Fasciolosis is an important disease that can occur in both animals. The aim of this study was to examine the possible mutual transmission of this disease in Hokkaido Prefecture. A total of 105 Fasciola flukes were obtained from sika deer and 96 from domestic cattle. The Fasciola flukes in Japan are reported to possess no mature sperm. However, in this study, 14 flukes from sika deer and eight flukes from cattle contained mature sperm in their seminal vesicles. All the Fasciola flukes from the two host animals had Fh/Fg type in nuclear phosphoenolpyruvate carboxykinase (pepck) gene, with a mixed fragment pattern derived from F. hepatica and F. gigantica, which are considered to be hybrid Fasciola flukes. However, almost all the flukes had Fsp1 haplotype in NADH dehydrogenase subunit 1 (nad1) gene, indicating that their maternal lineage was F. hepatica. A new haplotype, Fsp3, was detected in one fluke obtained from cattle and differed in one nucleotide from Fsp1. Therefore, the Fasciola flukes detected in both host species had almost identical molecular characteristics. These findings suggest the mutual transmission of Fasciola flukes between sika deer and domestic cattle in Hokkaido.

Time series data of a broadleaved secondary forest in Japan as affected by deer and mass mortality of oak trees.

BackgroundAbandonment of broadleaved secondary forests that have been used for various purposes may cause the loss of biodiversity. Some of these forests suffer from diseases such as Japanese oak wilt. An increasing number of deer also impact some of them. Monitoring and recording the status of such forests is important for their proper management.New informationThis data set provides a concrete example of temporal changes in a temperate broadleaved secondary forest. The forest has been damaged by mass mortality of oak trees caused by Japanese oak wilt disease. In addition, the forest has been under foraging pressure by sika deer (Cervus nippon Temminck). The data set can provide information on how such a forest has changed in species composition of the canopy and sub-canopy layers and in species occurrence in the understory layer.

Estimation of deer damage to soybean production in eastern Mississippi: Perception versus reality

ABSTRACTSoybean (Glycine max) is one of Mississippi's most profitable agricultural crops. White‐tailed deer (Odocoileus virginianus) consume soybeans each year because of the palatability and nutritional content of the plant and may cause economic damage to soybean producers. We estimated the amount of damage (browsing and loss of yield) caused by deer within 5 soybean fields in eastern Mississippi, USA, and compared damage with the number of deer using each field during the 2012 and 2013 growing seasons. Although deer browsing did reduce soybean height, soybean yield was unaffected during both years of our study. Our results suggest that perception of deer damage likely exceeds actual yield loss. Other environmental factors, such as competition from field border vegetation and field margin effects, may better explain spatial variation in soybean yield throughout fields. Soybean growers in the southeastern United States may benefit from targeting investment in deer damage control more efficiently. © 2017 The Wildlife Society.

Survival analysis and computer simulations of lethal and contraceptive management strategies for urban deer

I monitored survival of 34 female white-tailed deer (Odocoileus virginianus) in Bloomington, Minnesota, from October 1996 to December 1999. Twenty deer died: nineteen were killed by vehicles, and one was killed in a deer-removal program conducted by an adjacent suburb. Summer survival was high and varied little over the 3 years of study (range = 0.93 to 0.95). Fall survival ranged from 0.84 to 1.00, and winter survival was generally high during the 3 years of study, except during a severe winter (range = 0.72 to 0.95). I calculated population growth rates (λ) from Leslie matrix projections, using these survival estimates and productivity data collected from road-killed female deer in the Twin Cities (Minneapolis-St. Paul, Minnesota, USA) metropolitan area. When winter survival was high (0.94), my model simulations indicated the Bloomington deer population increased by 21% when no deer management program was in place. When a low winter survival rate (0.72) was modeled, the population decreased by 7%, even when no deer management program was implemented. I modeled what impact contraception may have on population growth and concluded that treating >50% of adult female deer was necessary to stabilize population growth, and treating all females was necessary to decrease population growth under high winter survival conditions. I concluded that removal programs are more effective than immunocontraception programs because survival contributes more to population growth rates in deer populations than fecundity. I recommend removing 20% and 40% of adult female deer in the population to cause the population to stabilize or to reduce deer numbers, respectively. I recommend managers collect deer-vehicle collision data because these data potentially represent the most accurate and easily-obtainable life history component of an urban deer herd.

Factors influencing survival of desert mule deer in the greater San Andres Mountains, New Mexico

Mule deer numbers have declined precipitously in the San Andres Mountains of southcentral New Mexico. To assess reasons for population declines, we monitored condition, survival, and causes of mortality for a range of 37 to 64 radio-collared, >1.5-year-old female mule deer annually, and a range of 14 to 31 radio-collared, >1.5-year-old male mule deer annually from 2003 to 2009, and modeled environmental factors affecting survival. We found annual survival rates of 0.74 to 0.86 for females and 0.74 to 0.92 for males, rates that were similar among years within sexes. Causes of mortality for 50 radio-collared females and 22 radio-collared males included predation (13 females, 2 males), accidents (4 females, 1 male), malnutrition (13 females, 7 males), disease (6 females, 2 males), unknown-not-predation (3 females, 6 males), unknown (11 females, 3 males), and harvest (0 females, 1 male). Condition of females varied among years and was poor in most years (i.e., lactating females had 1.0) > 0.937). Potential rates of increase of mule deer in the greater San Andres Mountains were limited by production and survival of fawns, rather than adult mortality.

The effect of natural and human-induced habitat conditions on number of roe deer: case study of Vojvodina, Serbia

Roe deer (Capreolus capreolus L.) have greatly expanded in both distribution and abundanceduring the last few decades, and are the most abundant cervids in Europe today. The aim of this paper is to determine the factors that have the most considerable impact on roe deer numbers in the Vojvodina region (North Serbia). Environmental (area in ha, total area of forest and total area of meadows and pastures in hunting ground) and anthropogenic (number of registered hunters, number of hunting sections, number of gamekeepers and roads in km on 1,000 ha) factors had been shown to influence the number of roe deer in Vojvodina region. A multiple regression analysis was carried out as the main statistical approach. The mapping of certain parameters was done using ArcGIS 9.2 software in order to establish the relation between the roe deer population and the different environmental and anthropogenic conditions. The results signify that the roe deer number dependency in the Vojvodina region is a very complex and multi-factorial phenomenon, strongly influenced by human induced modifications.

Dominance of the Enterocytozoon bieneusi genotype BEB6 in red deer (Cervus elaphus) and Siberian roe deer (Capreolus pygargus) in China and a brief literature review.

Enterocytozoon bieneusi is the most frequently diagnosed microsporidian species in humans and is also found in a wide range of animals. It is considered to be an important but neglected zoonotic pathogen. With the development of deer bred in captivity, the number of deer has been increasing in recent years in China and there are more people involved in this work. The aims of this study were to determine prevalence and genotypes of E. bieneusi in red deer (Cervus elaphus) and Siberian roe deer (Capreolus pygargus), and to assess their potential zoonotic transmission. A total of 122 fecal specimens were collected from 104 red deer and 18 roe deer from three deer farms in Heilongjiang and Jilin Provinces, China. Enterocytozoon bieneusi was detected and genotyped by PCR and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. The average infection rate was 8.2% (10/122), with 7.7% (8/104) for red deer and 11.1% (2/18) for roe deer. Two genotypes were identified: a known genotype BEB6 (n = 9) and a novel genotype named HLJD-VI (n = 1). This is the first report of E. bieneusi infection in Siberian roe deer. The fact that genotype BEB6 was detected previously in one human case of microsporidiosis, and that genotype HLJD-VI fell into zoonotic group 1, suggest the possibility of transmission to humans. A brief review of E. bieneusi genotypes in deer worldwide shows that 40 genotypes have been found in seven deer species, with genotype BEB6 being predominant.

Spring spotlight counts provide reliable indices to track changes in population size of mountain‐dwelling red deer Cervus elaphus

Monitoring changes in animal abundance is a central issue in conservation biology. Population indices may be a valuable support to wildlife managers in coarse‐scale survey programs, as they normally represent more intuitive and less expensive monitoring tools if compared with absolute estimates. Reliable indices of relative abundance, however, require validation against some known standards. We used mark‐resight estimates to investigate the performance of indices derived from spring spotlight surveys to track changes in a mountain‐dwelling population of red deer Cervus elaphus within the Stelvio National Park, central Italian Alps. Every spring between 2008 and 2015 we conducted four sessions of roadside‐counts using spotlights, recording all sightings of marked and unmarked individuals; the zero‐truncated Poisson log‐normal estimator was applied in a robust‐design fashion to return absolute estimates of spring abundance. We then compared the mark‐resight estimates with two indices of abundance, the maximum number (MNC) and the average number (ANC) of deer counted every spring in the four sampling occasions, using linear models on log‐transformed data. Both the MNC and the ANC proved reliable indices of relative abundance, as their relationships with mark‐resight estimates were positive and highly significant, and the beta coefficients of linear models were not significantly different from 1. The same analysis conducted on subsets of secondary sampling occasions suggested that at least 3 repeated counts every spring are necessary to consistently track changes in deer population size. The reliability of spotlight‐based indices to monitoring deer population changes has been widely debated, possibly owing to inconsistent performances of the method in different landscapes. For mountain‐dwelling deer populations living in similar habitats, our results suggest that spring spotlight surveys represent valuable tools in support of wildlife managers for long‐term, large‐scale monitoring programs; furthermore, they can provide appropriate indices to estimating population growth rates and thus modelling deer population dynamics.

Efficacy of surgical sterilization for managing overabundant suburban white‐tailed deer

ABSTRACTBased on decades of increasing deer effects on local biodiversity, agricultural damage, and deer–vehicle collisions, we implemented a suburban white‐tailed deer (Odocoileus virginianus) research and management program in 2007 on Cornell University lands in Tompkins County, New York, USA. We attempted to reduce deer numbers by surgically sterilizing female deer in the 445‐ha suburban core campus via tubal ligation and ovariectomy. From 2007 to 2013, we sterilized 93 deer and radiocollared 67 adult females to monitor fawning. Tubal ligation and ovariectomy surgeries appeared to prevent birth in 96% and 100% of treated female deer, respectively. We implemented a camera survey, used a mark–resight model in Program NOREMARK to estimate annual deer abundance, and observed no reduction in female abundance by winter 2013. Conversely, we noted a 38% and 79% decrease of total adult females and fawns visible in sampled photographs, respectively, and an 873% increase in adult male visitation to camera traps on core campus. Surgical sterilization appeared to be ineffective for reducing the abundance of a geographically open population of white‐tailed deer in the absence of lethal management. We do not recommend surgical sterilization as a stand‐alone method for communities wishing to pursue mitigation of deer impacts with nonlethal approaches. © 2016 The Wildlife Society.

Management of on-farm risk to livestock from bovine tuberculosis in Michigan, USA, white-tailed deer: Predictions from a spatially-explicit stochastic model

The eradication of bovine tuberculosis (bTB), caused by Mycobacterium bovis, from cattle in many locations worldwide is complicated by endemic foci of the disease in free-ranging wildlife. Recent simulation modeling of the bTB outbreak in white-tailed deer (WTD) in Michigan, USA, suggests current management is unlikely to eradicate bTB from the core outbreak area (DMU 452) within the next three decades. However, some level of control short of eradication might sufficiently reduce transmission from deer to cattle to a point at which the negative effects of bTB on the cattle industry could be reduced or eliminated, while minimizing the negative consequences of reducing deer numbers. We extended our existing spatially-explicit, individual-based stochastic simulation model of bTB transmission in WTD to incorporate transmission to cattle, to characterize the effects of vaccination and increased harvest of WTD on cattle herd breakdown rates, to examine the effects of localized culling or vaccination of WTD in the vicinity of cattle farms, to assess the effects of concurrent deer baiting, and to determine the effect of progressive restriction of deer/cattle contact on herd breakdowns. A spatially-explicit “cattle layer” was constructed describing the spatial locations, farm size and cattle density of all farms within and directly adjacent to DMU452. Increased hunter harvest or vaccination of deer, or a combination, would likely decrease the number of cattle herd breakdowns to <1 per year in less than 15 years. Concurrent deer baiting variably increased the time necessary to achieve zero breakdowns. The prevalence of bTB in deer needed to fall below ∼0.5% before ≤1 herd breakdown per year could be expected, and below 0.1% before zero breakdowns were likely. Locally applied post-harvest deer culling or vaccination also rapidly reduced herd breakdowns. On farm biosecurity measures needed to reduce deer to cattle contact by >95% in order to reliably reduce herd breakdowns, and did not achieve zero breakdowns in the absence of other deer controls.

Overpasses and underpasses: Effectiveness of crossing structures for migratory ungulates

Maintenance of movement corridors is a fundamental component of the conservation of biological diversity, and is especially critical for terrestrial species that migrate extended distances. Highways and interstate freeways fragment corridors and often result in increased mortality of terrestrial migrants from collisions with vehicles. Wildlife crossing structures are an important tool in multiple ecosystems to allow safe passage for wildlife across roadways. Indeed, crossing structures have been used extensively in Europe and with increasing frequency in North America to reconnect fragmented habitats for numerous species. Few projects, however, have documented responses to >1 structure type simultaneously that are close to one another. We used mule deer (Odocoileus hemionus), a widespread species across diverse bioregions in western North America, to test hypotheses about efficacy of 2 different types of crossing structures for ungulates. We documented behavioral responses and use of overpasses and underpasses by mule deer. Our metrics to evaluate success included passage rates and the number of animals that crossed each structure. Crossing structures were used by mule deer immediately following construction and although all of the crossing structures were used, we observed greater passage rates at overpasses than underpasses. Wildlife crossing structures reduced habitat fragmentation and enhanced connectivity by allowing safe passage across US 93. More importantly, those structures succeeded in removing a large number of mule deer from the roadway making US 93 safer for wildlife and motorists. © 2016 The Wildlife Society.