Allozyme and mitochondrial DNA analysis of a hybrid zone between white-tailed deer and mule deer (Odocoileus) in west texas

Thirty allozyme loci and 35 mitochondrial DNA (mtDNA) restriction sites were examined in 24 white-tailed deer and 46 mule deer from a hybrid zone in West Texas. A common mtDNA genotype is shared by all of the mule deer with 67% of the white-tailed deer. At the albumin locus, 13% of the white-tailed deer and 24% of the mule deer are heterozygous, sharing alleles that are otherwise species-specific in allopatric populations; 7% of the mule deer are homozygous for the allele that is characteristic of allopatric white-tailed deer. Gene flow appears to have been bidirectional, with greater genetic introgression into mule deer. The mtDNA data suggest that matings between white-tailed and mule deer have occurred in the past. Despite evidence of genetic introgression, analysis of multilocus genotypes indicates that none of the deer examined is an F₁ hybrid. Production of such hybrids appears to be generally uncommon in North American deer; management plans that assume otherwise should be reconsidered.This work was supported by an NIH Biomedical Research Support Grant, Texas Agricultural Experiment Station Program Development and Expanded Research Awards, the Caesar Kleberg Research Program in Wildlife Ecology, and a Natural Sciences and Engineering Research Council Operating Grant.     

The effect of agricultural land use practice on habitat selection of red deer

The population of red deer (Cervus elaphus) has increased substantially in many western European countries during recent decades. Simultaneously, agricultural practices have undergone major changes. Observations suggest that meadows and pastures are important sources of nutrients for deer, but there are few studies quantifying the selection of agricultural land by deer in general. Here, we study red deer selection of various types of agricultural land and the history of land use (times of fertilisation and since renewal) in Norway. We used data from 14 female and 12 male red deer with GPS collars during the years 2007–2010. Our study design was to compare pairs of agricultural fields that had received “low” and “high” use by a given individual red deer and data were analysed by using case–control logistic regression. Our results showed that both sexes selected meadows over other types of agricultural land. Females selected intensively fertilised meadows and meadows of intermediate age, while male selection did not depend on meadow age (time since renewal) or fertilisation. The smaller females thus selected meadows of high quality, while the larger males continued to use old meadows of lower quality but rich in biomass. Our analysis suggests that a decreasing supply of meadows in the future due to lower production of livestock fodder may also affect management of red deer, and that a future change in the intensity of agricultural practices may affect sexes of wild large herbivores differently.     

Stopover ecology of a migratory ungulate

1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus- a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18-144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5·3 and 6·7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa.     

Increases in residential and energy development are associated with reductions in recruitment for a large ungulate

Land‐use change due to anthropogenic development is pervasive across the globe and commonly associated with negative consequences for biodiversity. While land‐use change has been linked to shifts in the behavior and habitat‐use patterns of wildlife species, little is known about its influence on animal population dynamics, despite the relevance of such information for conservation. We conducted the first broad‐scale investigation correlating temporal patterns of land‐use change with the demographic rates of mule deer, an iconic species in the western United States experiencing wide‐scale population declines. We employed a unique combination of long‐term (1980–2010) data on residential and energy development across western Colorado, in conjunction with congruent data on deer recruitment, to quantify annual changes in land‐use and correlate those changes with annual indices of demographic performance. We also examined annual variation in weather conditions, which are well recognized to influence ungulate productivity, and provided a basis for comparing the relative strength of different covariates in their association with deer recruitment. Using linear mixed models, we found that increasing residential and energy development within deer habitat were correlated with declining recruitment rates, particularly within seasonal winter ranges. Residential housing had two times the magnitude of effect of any other factor we investigated, and energy development had an effect size similar to key weather variables known to be important to ungulate dynamics. This analysis is the first to correlate a demographic response in mule deer with residential and energy development at large spatial extents relevant to population performance, suggesting that further increases in these development types on deer ranges are not compatible with the goal of maintaining highly productive deer populations. Our results underscore the significance of expanding residential development on mule deer populations, a factor that has received little research attention in recent years, despite its rapidly increasing footprint across the landscape.     

Red deer hunting—commercializing versus availability

Many deer populations in Europe and North America have increased in abundance over the last decades. The increasing populations potentially entail both ecological and economic challenges and opportunities, but in practice we still know little about the extent to which these opportunities are being exploited in different management systems. The Norwegian red deer population has increased in density and expanded rapidly since the 1950s. Traditionally, red deer hunting has been undertaken by the local landowner and his relatives and friends. The present large population raises the question whether attracting other hunters could provide a higher economic return for the landowners and, if so, if they are interested in providing such hunting opportunities. We designed a survey to learn more about the landowners, both with respect to the present level of hunting income as well as economic costs of, for example, forest and agricultural damage; we also sought to understand their interest in increasing their income from red deer hunting and potential obstacles to realizing such an increased economic benefit. The results indicate that landowners on average think that red deer populations on their land result in higher costs than income but are nevertheless satisfied with the way things are. This highlights that increased numbers of deer need not automatically lead to more income for landowners and that the potential for income may be hindered by cultural factors such as reluctance to allow access to non-local hunters.     

Golden Eagles Aquila chrysaetos: land use and food in northeast Scotland

This paper contrasts changes in breeding numbers and breeding success of Golden Eagles Aquila chrysaetos on four areas with different land uses. On land primarily used for deer stalking but also for grouse shooting, and supporting abundant prey, the number of eagle pairs was steady in 1944-80. On deer land with fewer prey, the number of pairs declined greatly in the 1960s, when deer carrion became scarcer following increased shooting of red deer. On grouse moors incorporating deer stalking, the number of pairs declined in the 1950s due to persecution by gamekeepers, and then largely recovered as this lessened. On grouse moors with little or no stalking, the number of pairs fell after 1946 and remained low due to persecution, which has continued since then. Eagles on grouse moors bred poorly due to persecution. On deer land they were seldom persecuted by estate staff, and bred well. On an area of deer land, the mean annual number of young reared per undisturbed clutch in summer was related to the estimated weight of prey in the spring of the same year. The eagles have remained fairly pesticide-free, and bred well in 1963-65 when more contaminated birds in west Scotland bred poorly.     

Land abandonment and changes in snow cover period accelerate range expansions of sika deer

Ongoing climate change and land‐use change have the potential to substantially alter the distribution of large herbivores. This may result in drastic changes in ecosystems by changing plant–herbivore interactions. Here, we developed a model explaining sika deer persistence and colonization between 25 years in terms of neighborhood occupancy and habitat suitability. We used climatic, land‐use, and topographic variables to calculate the habitat suitability and evaluated the contributions of the variables to past range changes of sika deer. We used this model to predict the changes in the range of sika deer over the next 100 years under four scenario groups with the combination of land‐use change and climate change. Our results showed that both climate change and land‐use change had affected the range of sika deer in the past 25 years. Habitat suitability increased in northern or mountainous regions, which account for 71.6% of Japan, in line with a decrease in the snow cover period. Habitat suitability decreased in suburban areas, which account for 28.4% of Japan, corresponding to land‐use changes related to urbanization. In the next 100 years, the decrease in snow cover period and the increase in land abandonment were predicted to accelerate the range expansion of sika deer. Comparison of these two driving factors revealed that climate change will contribute more to range expansion, particularly from the 2070s onward. In scenarios that assumed the influence of both climate change and land‐use change, the total sika deer range increased by between +4.6% and +11.9% from the baseline scenario. Climate change and land‐use change will require additional efforts for future management of sika deer, particularly in the long term.     

Ecological function losses caused by monotonous land use induce crop raiding by wildlife on the island of Yakushima,southern Japan

Mass production is a logical outcome of price competition in a capitalist economy. It has resulted in the need for large-scale logging and planting of commercial crops. However, such monotonous land use, or monoculture, has damaged various ecological functions of forests and eroded the beneficial public service provided by forests. In Japan, the most widespread monotonous land use is associated with coniferous plantations, the expansion of which was encouraged by Forest Agency policies from 1958 that were aimed at increasing wood production. By 1986, half of all forested lands had been transformed into single-species conifer plantations. These policies may damage the ecological functions of forests: to provide stable habitats for forest wildlife. In particular, food supplies for wildlife have fluctuated greatly after several decades of logging. Some species have therefore changed their ecology and begun to explore novel environments proactively in order to adapt to such extreme fluctuations. Such species have started to use farmlands that neighbor the plantations. In this sense, crop raiding by wildlife can be regarded as a negative result of monotonous land use due to the loss of ecological functions. Therefore, habitat management to rehabilitate ecological functions and to reorganize the landscape will be required in order to resolve the problem of crop raiding by wildlife. This study examines crop raiding by Japanese deer (Cervus nippon) and monkeys (Macaca fuscata) on the island of Yakushima, which typifies crop-raiding situations in Japan.     

我国人工养麝研究进展及养麝效益问题

我国人工养麝已历经半个世纪,人工养麝研究取得了重要进展,但从整体上看,疾病控制、产香量及养麝的整体效益仍是有待深入研究的课题.为进一步推进我国人工养麝研究和养麝业的发展,现就一些主要的研究进展进行了综述,提出了麝场的经济效益公式,认为在现有的管理体制下,养麝规模越大,经济效益反而越低.鉴于我国养麝业的特殊性及其存在的具体问题,国家应该将养麝业作为一项公益性的事业予以特殊的政策和资金方面的扶持.同时,鼓励医药企业积极投身于养麝研究与麝场建设,以共同推进养麝业的持续健康发展,从而使人工养麝能够为我国麝资源的保护和传统中药的传承做出应有的贡献.     

Regional-Scale Assessment of Deer Impacts on Vegetation Within Western Connecticut,USA

Abstract: High densities of white-tailed deer (Odocoileus virginianus) are believed to cause broad-scale forest regeneration failure and loss of plant diversity. But, the empirical basis for such presumptions is limited. We, therefore, conducted a survey in western Connecticut, USA, woodlots to examine how spatial variation in deer densities influences variation in impacts on plant species abundance, identity and diversity, and tree regeneration. We also used a Geographic Information System to quantify trends between land-cover type and deer density. Deer density was not correlated with any vegetation or land use variable. This suggests that deer density is not a leading factor determining variation in vegetation impacts across western Connecticut.     

Spatial distribution and landscape associations of large-antlered deer

For more than a century, the Boone and Crockett Club has kept records of harvest locations for 38 categories of North American big game, which includes measurement details and sizes of enduring characteristics (e.g., antlers, skulls, horns). All white-tailed deer (Odocoileus virginianus) entered in the Club records (i.e., record deer) have large antlers because the measurements must meet or exceed a minimum size to qualify for entry. We used the records from the Club to test the hypothesis that the spatial distribution in the harvest of record deer was related to the number of antlered deer harvested, variations in land productivity, soil mineral content, and attributes of land cover for 9 states in the midwestern United States. We used a Bayesian theoretical framework to develop a spatial model that examined the influence of explanatory variables on the number of record deer harvested in each county. In our study area, 3,658 record deer were harvested in 692 of the 856 counties (80.8%). More record deer were harvested in counties that had more high-contrast edges, less contiguous land cover, and greater variation in soil productivity. These results provide information for managers and hunters to better understand the spatial distribution of record deer and factors that are correlated with their distribution. © 2019 The Wildlife Society.     

Assessing landscape resistance to roe deer dispersal using fuzzy set theory and multicriteria analysis: a case study in Central Spain

The central Iberian Peninsula has one of the highest densities of roe deer populations in Spain. A new motorway is planned to pass through the middle of the distribution of roe deer, thus making it necessary to conduct a connectivity analysis. A map of resistance to roe deer dispersal movements was obtained based on the literature and expert judgment. Three factors were selected: land use (defined by the ability to hide movements, food source, and degree of naturalness), landforms, and influence due to proximity to elements that increase (such as roads and urban areas) or decrease (water resources and proximity to optimal habitat patches) resistance at the local level. Different combinations of factors derived using the analytical hierarchy and fuzzy logic processes were analysed and compared with the real distribution of the species. More realistic resistance (cost) values were obtained for gamma values close to 0.9. This highlights the greater predominance of the fuzzy sum over the fuzzy product in modelling the cost surface. Better results were obtained in scenarios where the predominant factors were either land use and landforms or land use and proximity to human-modified areas. This indicates that roe deer will readily range far from their optimal patches if the land use provides partial cover. These movements appear to be conditioned by steep terrain. Our case study offers a good example of building a cost resistance matrix to help locate areas where the expansion of the species may be curbed or encouraged.     

Climate change is the primary driver of white‐tailed deer (Odocoileus virginianus) range expansion at the northern extent of its range; land use is secondary

Quantifying the relative influence of multiple mechanisms driving recent range expansion of non‐native species is essential for predicting future changes and for informing adaptation and management plans to protect native species. White‐tailed deer (Odocoileus virginianus) have been expanding their range into the North American boreal forest over the last half of the 20th century. This has already altered predator–prey dynamics in Alberta, Canada, where the distribution likely reaches the northern extent of its continuous range. Although current white‐tailed deer distribution is explained by both climate and human land use, the influence each factor had on the observed range expansion would depend on the spatial and temporal pattern of these changes. Our objective was to quantify the relative importance of land use and climate change as drivers of white‐tailed deer range expansion and to predict decadal changes in white‐tailed deer distribution in northern Alberta for the first half of the 21st century. An existing species distribution model was used to predict past decadal distributions of white‐tailed deer which were validated using independent data. The effects of climate and land use change were isolated by comparing predictions under theoretical “no‐change between decades” scenarios, for each factor, to predictions under observed climate and land use change. Climate changes led to more than 88%, by area, of the increases in probability of white‐tailed deer presence across all decades. The distribution is predicted to extend 100 km further north across the northeastern Alberta boreal forest as climate continues to change over the first half of the 21st century.     

Estimating abundance of Sitka black-tailed deer using DNA from fecal pellets

Densely vegetated environments have hindered collection of basic population parameters on forest-dwelling ungulates. Our objective was to develop a mark–recapture technique that used DNA from fecal pellets to overcome constraints associated with estimating abundance of ungulates in landscapes where direct observation is difficult. We tested our technique on Sitka black-tailed deer (Odocoileus hemionus sitkensis) in the temperate coastal rainforest of Southeast Alaska. During 2006–2008, we sampled fecal pellets of deer along trail transects in 3 intensively logged watersheds on Prince of Wales Island, Alaska. We extracted DNA from the surface of fecal pellets and used microsatellite markers to identify individual deer. With genotypes of individual deer, we estimated abundance of deer with moderate precision (±20%) using mark–recapture models. Combining all study sites, we identified a 30% (SE = 5.1%) decline in abundance during our 3-year study, which we attributed to 3 consecutive severe winters. We determined that deer densities in managed land logged >30 years ago (7 deer/km², SE = 1.3) supported fewer deer compared to both managed land logged <30 years ago (10 deer/km², SE = 1.5) and unmanaged land (12 deer/km², SE = 1.4). Our study provides the first estimates of abundance (based on individually identified deer) for Sitka black-tailed deer and the first estimates of abundance of an unenclosed ungulate population using DNA from fecal pellets. Our tool enables managers to accurately and precisely estimate the abundance of deer in densely vegetated habitats using a non-invasive approach. © 2011 The Wildlife Society.     

基于最大熵模型的野生马麝夏季生境适宜性研究

野生马麝(Moschus chrysogaster)是珍稀濒危资源动物,分布于我国青藏高原及周边地区。甘肃兴隆山国家级自然保护区是野生马麝最重要的分布区之一,深入了解保护区的生境结构、质量及分布是对区域内野生马麝进行成功保护的前提和基础,但迄今缺乏大尺度的马麝生境适宜性研究。利用实地调查得到的兴隆山保护区的野生马麝夏季分布点数据,采用最大熵(MaxEnt)模型,结合地形、归一化植被指数、距河流距离、距道路距离等环境变量数据,进行野生马麝的夏季生境适宜性分析。结果表明：影响野生马麝夏季生境适宜性的主要生态因子是海拔、坡向、植被和河流,其贡献率分别达40.3%,23.4%,18.6%和10.9%;兴隆山保护区野生马麝的夏季潜在适宜生境分布面积为123.34 km²,占整个保护区的41.11%,占保护区林地的61.92%;野生马麝夏季潜在适宜生境主要集中在保护区的中部和西部,其中高适宜性生境约为保护区的4.47%,各适宜区间及适宜区之内均存在一定程度的不连续分布。为加强对兴隆山保护区野生马麝种群及生境的就地保护,建议通过生境保育措施,提高野生马麝潜在分布区的生境适宜性,...     

The economic value of publicly accessible deer hunting land

Access to lands for hunting is widely recognized as critical to sustaining and developing participation in hunting. Deer hunters comprise a substantial portion of recreational hunters in the United States, and numerous stakeholders benefit from the deer management services provided by hunters on public lands. We estimated the economic value of publicly accessible deer hunting land in Michigan using economic models of hunting destinations for hunters in the archery season and for hunters in the firearm season. We found that the amounts of state-owned hunting land, federally owned hunting land, and publicly accessible, privately owned Commercial Forest Act land are significant (P < 0.001) and positive determinants of hunting destinations. The annual economic value of Michigan's publicly accessible hunting land to archery and firearm deer hunters, beyond hunter expenditures, was estimated to be over $80 million. Access to state-owned land accounted for approximately $50 million in annual economic value to Michigan deer hunters. The average per-acre value of publicly accessible hunting land is greatest in the Southern Lower Peninsula of Michigan, where public access is scarce and the majority of hunters reside. Understanding the economic values hunters derive from publicly accessible hunting lands will enable managers and policy makers to make better decisions when considering policy options that involve reducing or increasing public access. © 2011 The Wildlife Society.     

Influence of Holocene environmental change and anthropogenic impact on the diversity and distribution of roe deer

Extant patterns of population structure and levels of diversity are a consequence of factors that vary in both space and time. Our objective in this study is to investigate a species that has responded to both natural and anthropogenic changes in ways that have shaped modern populations and provide insight into the key processes. The roe deer (Capreolus capreolus) is one of the two species of deer native to Britain. During the last glacial maximum (LGM), the British habitat was largely under ice and there was a land bridge to mainland Europe. As the Earth warmed during the early Holocene, the land bridge was lost. Subsequent hunting on the British mainland left the southern region extirpated of roe deer, whereas a refugial population remained in the north. Later reintroductions from Europe led to population expansion, especially in southern United Kingdom. Here, we combine data from ancient and modern DNA to track population dynamics and patterns of connectivity, and test hypotheses about the influence of natural and anthropogenic environmental change. We find that past expansion and divergence events coincided with a warming environment and the subsequent closure of the land bridge between Europe and the United Kingdom. We also find turnover in British roe deer haplotypes between the late-Holocene and modern day that have likely resulted from recent human disturbance activities such as habitat perturbation, overhunting and restocking.     

New developments reproductive technologies in deer

In vitro embryo production is the platform for advanced reproductive technologies, such as cloning. The in vitro embryo production system developed for farmed red deer (Cervus elaphus) evolved along similar lines to that pioneered by other domestic species researchers. However, applying existing in vitro embryo production methods from these other species resulted in limited success and has necessitated developing a species-specific methodology for red deer based on the their physiology. Analysis of oviduct fluid led to the development of a semi-defined fertilization and culture media system, Deer Synthetic Oviduct Fluid (DSOF), which resulted in successful culture of red deer embryos to the blastocyst stage. Transvaginal ultrasound-guided ovarian examination and ovum pickup has enabled the study of seasonality constraint and propagation from selected female genetics, respectively. During the 4-month breeding season (April-July), 15% of cleaved oocytes developed to blastocysts, whereas no blastocysts developed from oocytes collected after July. The process of developing an in vitro embryo production system for farmed red deer may serve as a beneficial model for the propagation of endangered cervine species.     

Relationships between musk extraction, social rank and tail-rubbing in male Alpine musk deer, Moschus sifanicus

Musk deer (Moschus spp.) are small, solitary forest ruminants well-known for the musk secreted by adult males. Because of illegal hunting and habitat degradation and loss, the five species of musk deer are classified as endangered. Musk deer farming has been a positive example of ex situ conservation, maintaining deer numbers whilst sustaining musk production. This study was conducted at the Xinglongshan Musk Deer Farm in Gansu Province in northwest China, and was designed to explore the relationships among musk extraction, fighting ability and social rank in captive, male alpine musk deer (Moschus sifanicus). Results showed that musk production was related to a male’s rank in the dominance hierarchy. Males in the middle rank of the dominance hierarchy tended to produce more musk than deer of higher and lower ranks. This is due to the time-energy budgeting patterns and captive stress of males with different status in the dominance hierarchy. That is, high-ranking males need to budget more time and energy to maintain their higher rank, while low-ranking males are exposed to more aggression from higher-ranking individuals, thus limiting their access to resources such as food and shelter. Accordingly, high-ranking and low-ranking males endured more stress than middle-ranking males, negatively affecting their annual musk production. Supporting the correlation between musk production and the frequency of tail-rubbing behavior was not significant, average musk extraction could not be predicted based on the frequency of tail-rubbing alone. Status in the dominance hierarchy, however, was positively correlated with tail-rubbing frequency, with males of higher rank tending to tail-rub more frequently. Conflict winners tended to initiate tail-rubbing after the conflict; tail-rubbing accounted for 83.33% of the post-conflict behavior expressed by the winner. Tail-rubbing was one of the behavioral rewards of winning a conflict and was also related to releasing aggression; not solely for scent marking territory and trails. Based on the results of this study, there was no direct relationship between musk production and captive males’ status in the dominance hierarchy (and, therefore, in the intensity of aggression displayed). If the sole aim of musk deer farms is to domesticate musk deer for maximum production of musk, we suggest that highly aggressive males be removed from the population. Musk production will remain unchanged, however, aggression level and intensity of fighting could be lessened thus reducing farming costs.