冶勒自然保护区林麝对生境选择研究

1995年在相岭山系的冕宁冶勒自然保护区，采用作者新近提出的临时空间样方法，以Vanderloeg和Scavia选择指数对林麝对生境的选择进行了研究，结果表明7～8月份，林麝喜欢活动于竹子密度不大（n＝0～15m     

四川9种有蹄类动物夏秋季活动节律研究

基于全国哺乳动物观测网络中四川王朗、四姑娘山、贡嘎山及亚丁4个自然保护区2017年6—11月红外相机数据,利用相对丰富度指数RAI对四川羚牛(Budorcas tibetanus)、中华鬣羚(Capricornis milneedwardsii)、水鹿(Cervus unicolor)、毛冠鹿(Elaphodus cephalophus)、林麝(Moschus berezovskii)、高山麝(Moschus chrysogaster)、小麂(Muntiacus reevesi)、中华斑羚(Naemorhedus griseus)和岩羊(Pseudois nayaur) 9种有蹄类动物的相对种群数量和日活动规律进行研究。结果表明:(1)毛冠鹿在九种有蹄类动物中的相对丰富度(64. 12%)最高,且明显高于其他动物。(2)小麂、毛冠鹿和中华斑羚的日活动模式呈双峰型,具有明显的晨昏习性。(3)水鹿和中华鬣羚是典型的夜行性动物。(4)毛冠鹿在不同地区日活动模式均呈双峰型,但不同地区其活动高峰出现的时间段存在差异。有蹄类动物种群数量与食物资源、捕食压力等有关,活动节律受多种生物和非生物因素影响。研究四川地区有蹄类活动节律,可以为该地区有蹄类的监测及有效保护管理提供依据,并能为其捕食者行为学研究和保护提供数据支持。     

芜湖市郊土壤污染对土壤动物群落结构的影响

研究表明，芜湖市郊农田土壤动物群落的组成与数量随污染程度的加重而减少，土壤动物密度也呈同样的变化趋势，特别是中小型土壤动物，优势类群数量发生较大消长，常见类群和稀有类群的组成逐渐减少．多样性指数H与重金属污染程度之间关系因受到季节的影响而变得复杂：冬季和初夏污染较重样地优势类群数量减少，群落均匀性指数E增加而优势度指数C减小，多样性指数H较高；而春季处于过渡阶段，某些类群(如螨类)数量爆发，C增高，H较小．土壤动物群落密度一类群指数DG随污染加重而减小．受到重金属污染的农田土壤动物的表聚性减弱，甚至出现逆分布现象．图1表4参15     

浑善达克沙地榆树疏林植被和土壤的空间分异特征

榆树(Ulmus pumila)疏林是分布在浑善达克沙地上的天然植被类型,也是沙地植被演替的顶级群落,在维持区域生态稳定性方面发挥着重要作用。深入研究榆树疏林植被和土壤的空间分异特征对于深化认识榆树疏林中的植物共生机制具有重要意义。以浑善达克沙地榆树疏林为研究对象,在东部、南部、西部和北部4个区域,采用改进的Whittaker取样法开展植被调查和样品取样,分析了榆树疏林植被的空间分布特征,同时探讨了影响植被分布的环境因子。结果表明,(1)榆树的种群密度在东部区域最高(270.00 plant·hm~(-2)),在南部区域最低(116.67 plant·hm~(-2)),北部和西部区域居中(分别为198.33plant·hm~(-2)和141.67plant·hm~(-2)),这与该区域内的年均温度呈现出一致的空间分布规律。(2)榆树的种群密度分别与胸径、树高、冠幅呈现相反的空间分布规律,随着榆树个体的生长,种群密度逐渐降低,存在"自疏"现象。(3)灌木的群落密度与榆树的种群密度之间呈现出显著的负相关关系(P0.05),表明榆树种群与灌木群落在空间上存在不同的分布区域。(4)土壤理化性质与榆树种群和灌木群落的各项指标之间未呈现出显著的相关关系(P0.05),而与草本群落的部分指标呈现显著的相关关系(P0.05)。土壤对草本植物空间分布的影响较大,而对本木植物(包括乔木和灌木)空间分布的影响较弱。研究结果可为浑善达克沙地榆树疏林的保护和恢复提供理论支持。     

长江中游农区洪涝灾害后鼠类数量动态

1998年至2001年在湖南安乡对洪灾后的啮齿动物数量进行了监测，并以正常区为对照；与此同时，也对曾遭受过洪灾的其它地区进行了对比调查．调查发现，虽然洪灾对啮齿动物的种群影响很大，但其数量回升速度较快，退水半年左右，种群数量就会超过未发生洪灾的相邻地区．主要原因是洪灾使害鼠的生态压力减少，如害鼠数量大幅减少，而食物相对丰富，栖息空间相对较大以及天敌的数量减少等，从而使残存鼠和迁入鼠的数量得以迅速回升．洪灾后鼠密度回升到很高的地区，即使进行大面积的化学防治降低鼠密度后，其回升速度也不同于正常地区，同样具有快速反弹的特征．图4表2参15     

基于多方法融合的张家界大鲵自然保护区功能分区研究

中国大鲵(Andrias davidianus)为两栖类野生保护动物,在淡水生态系统中扮演着重要的角色和功能,但目前探讨其自然保护区功能分区的研究较少。以张家界大鲵自然保护区为研究对象,综合考虑地理环境、人类活动和大鲵分布等因素,融合最小费用距离、空间统计学方法的Ripley′s K函数、核密度分析和Iso聚类等多种方法,对张家界市域内水域的地理空间数据进行分析,得到大鲵自然保护区范围和功能分区。结果表明:(1)聚类结果所处位置和河段符合大鲵生境要求,并通过野外实地调查加以验证;(2)保护区总面积为13 101 hm~2,其中核心区面积占保护区总面积的35. 46%,缓冲区面积占35. 73%,实验区面积占28. 81%。功能分区结果考虑了大鲵水陆两栖特性,且符合生态和经济发展双重需要,对两栖类野生动物自然保护区功能分区研究具有一定的指导意义。     

鄱阳湖越冬灰鹤和白枕鹤的数量与集群特征

2012年10月至2013年4月,对鄱阳湖越冬灰鹤(Grus grus)和白枕鹤(Grus vipio)种群数量和分布、集群特征以及灰鹤的年龄组成进行调查。结果显示,灰鹤和白枕鹤数量单次记录到的最大值分别为599和600只。4个保护区34个湖泊(或农田)有18个湖泊(或农田)记录到灰鹤种群。灰鹤种群数量在1月初至3月初达到高峰,62.87%的灰鹤集中在鄱阳县白沙洲自然保护区。在12个湖泊(或农田)记录到白枕鹤分布,种群数量在2月底至3月初达到高峰,95.77%的白枕鹤集中在鄱阳湖国家级自然保护区。与以往鄱阳湖越冬鹤类种群分布相比,灰鹤主要集中的区域发生变化,而白枕鹤未发生变化。灰鹤和白枕鹤平均集群大小分别为(8.50±19.84)和(7.52±21.47)只,各时期差异均不显著(P0.05)。灰鹤集群以家庭群为主(占70.07%),聚集群次之(占23.36%);家庭群中2成1幼比例最大(占46.88%),聚集群中以5~9只的集群比例最大(占71.88%)。灰鹤家庭群平均大小为(2.76±0.69)只,聚集群平均大小为(13.84±20.82)只,2种集群类型在各时期之间大小差异均不显著(P0.05)。灰鹤集群中幼体占20.21%。针对鄱阳湖2种鹤类分别提出了相应的保护措施。     

川金丝猴家域的季节性差异

野生动物家域与生境利用是种群生态学的重要研究内容。川金丝猴(Rhinopithecus roxellana)属树栖灵长类,其分类地位以及种群结构都具有明显的自身特征,是森林物种的典型代表之一。利用家域模型和景观格局指数相结合的方法,对比分析了四川省白河国家级自然保护区一数量约250只的川金丝猴群的家域和生境利用的季节性差异,以及不同利用强度的家域空间格局特征。结果显示川金丝猴群家域与生境利用的季节性变化明显,(1)家域面积上,冬季的家域面积最小,仅为4.94 km~2,而春季家域面积开始逐渐扩大,秋季的家域面积达到最大,为25.17 km~2,并有更多的核心区域,但斑块数目较少,表明川金丝猴的秋季家域破碎化程度较低。冬季家域面积最小;夏季各利用强度生境的斑块数量均为最大值,表明夏季家域具有最高的破碎化程度。随着各季节家域范围内利用强度等级的降低,其空间利用面积也逐渐增大。(2)空间连通性上,秋季家域的区域连通性最高,而夏季和冬季的连通性较低;冬季家域利用的空间分布也较其他季节稍有分散。(3)生境利用上,川金丝猴家域主要分布在海拔2 000—3 200 m,坡度10°—50°,坡向区间为0°—60°、180°—360°的针叶林和针阔混交林中,而各季节生境利用面积占比却有所不同。该研究揭示了川金丝猴家域的季节变化及空间格局,为针对性保护与管理提供了科学依据。     

北京松山油松种群结构及空间分布格局

研究了北京松山自然保护区天然油松(Pinus tabulaeformisr)林的树冠结构和个体胸径,通过Ripley's K函数探讨了油松种群不同层次个体(幼树、小树和大树)的空间分布及空间关系,并探讨了地形(海拔高度、坡度)对油松种群空间分布的影响.结果表明,油松种群的胸径分布呈双峰型,应用Weibull函数拟合效果较好;树冠分布呈倒J型;胸径与冠幅存在显著的指数关系.油松种群呈聚集分布,但随高度增Jm(幼树→树→大树)聚集强度逐渐减弱,枯立木在样地内呈随机分布.枯立木与油松大树在1 m、5 m和13～18 m距离为显著正相关,幼树与小树在2～4 m和6～18 m距离呈显著正相关.海拔高度与油松种群呈正相关,坡度与幼树分布呈正相关,与小树和大树分布呈负相关.图5表2参24     

岷江上游刺旋花种群格局研究

在随机取样、解剖的基础上，对岷江上游灌丛优势种刺旋花（Convolvulustragacuthoiedes）建立种群静态生命表进行统计分析，以探索其在该地区特殊的生态学意义。结果表明：刺旋花种群的年龄结构为稳定发展型，存活曲线接近于decvyⅢ型；生活史中分别在1a和4～5a有两个死亡高峰；种群数量变化可用年龄结构模型Xx＝3．37·x－3．21（其中x表示年龄，Xx表示种群数量）来预测．X2检验法和区组样方方差法的格局分析结果都表明：刺旋花种群的分布格局随生境破碎程度和水分状况有很大差异，在不同样地分别趋向于随机分布和集群分布.     

Habitat and population modelling of roe deer using an interactive geographic information system

Management of German roe deer (Capreolus capreolus) populations is a challenge for wildlife managers and foresters because population densities are difficult to estimate in forests and forest regeneration can be negatively affected when roe deer density is high. We describe a model to determine deer population densities compatible with forest management goals, and to assess harvest rates necessary to maintain desired deer densities. A geographic information system (GIS) was used to model wildlife habitat and population dynamics over time. Our model interactively incorporates knowledge of field biologists and foresters via a graphical user interface (GUI). Calibration of the model with deer damage maps allowed us to evaluate density dependence of a roe deer population. Incorporation of local knowledge into temporally dynamic and spatial models increases understanding of population dynamics and improves wildlife management.     

Wildlife Loss through Domestication: the Case of Endangered Key Deer

Abstract:  Wildlife extinction represents the ultimate failure of wildlife conservation. It has many causes, some of them natural, but is increasingly tied to anthropogenic factors. Wildlife loss via domestication, however, is rarely considered. We evaluated the potential for inadvertent domestication of wildlife by determining the effect of feeding and watering on Key deer ( Odocoileus virginianus clavium ) density, group size, and distribution. Key deer sightings were significantly higher in areas (42 ha) surrounding the households that provided food and water (0.18 deer/m;  n = 8   ) than in randomly selected areas (0.03 deer/m;  t = 3.82, 14  df, p = 0.002   ). Average distance to a household providing food and water decreased logistically as group size increased, and large groups (>2 individuals each) were observed more frequently in areas where food and water were provided (27.5%) than in the randomly selected areas (7.5%). The incidence of large groups outside feeding areas (7.5%), however, was similar to the incidence of large groups during early urbanization (5.1%; 1968–1973). Our results suggest illegal feeding caused changes in density, group size, and distribution indicative of domestication. Because fresh water and food were primary selective pressures for Key deer before illegal feeding and watering, genetic changes may occur in the future. For those who value "wildness" in wildlife, domestication of wildlife species is a serious problem that must be addressed.     

Desert pastoralists’ negative and positive effects on rare wildlife in the Gobi

In arid regions of the developing world, pastoralists and livestock commonly inhabit protected areas, resulting in human–wildlife conflict. Conflict is inextricably linked to the ecological processes shaping relationships between pastoralists and native herbivores and carnivores. To elucidate relationships underpinning human–wildlife conflict, we synthesized 15 years of ecological and ethnographic data from Ikh Nart Nature Reserve in Mongolia's Gobi steppe. The density of argali (Ovis ammon), the world's largest wild sheep, at Ikh Nart was among the highest in Mongolia, yet livestock were >90% of ungulate biomass and dogs >90% of large‐carnivore biomass. For argali, pastoral activities decreased food availability, increased mortality from dog predation, and potentially increased disease risk. Isotope analyses indicated that livestock accounted for >50% of the diet of the majority of gray wolves (Canis lupus) and up to 90% of diet in 25% of sampled wolves (n = 8). Livestock composed at least 96% of ungulate prey in the single wolf pack for which we collected species‐specific prey data. Interviews with pastoralists indicated that wolves annually killed 1–4% of Ikh Nart's livestock, and pastoralists killed wolves in retribution. Pastoralists reduced wolf survival by killing them, but their livestock were an abundant food source for wolves. Consequently, wolf density appeared to be largely decoupled from argali density, and pastoralists had indirect effects on argali that could be negative if pastoralists increased wolf density (apparent competition) or positive if pastoralists decreased wolf predation (apparent facilitation). Ikh Nart's argali population was stable despite these threats, but livestock are increasingly dominant numerically and functionally relative to argali. To support both native wildlife and pastoral livelihoods, we suggest training dogs to not kill argali, community insurance against livestock losses to wolves, reintroducing key native prey species to hotspots of human–wolf conflict, and developing incentives for pastoralists to reduce livestock density.     

On estimating Hooded crow density from line transect data through exponential mixture models

Line transect sampling is a distance sampling method widely used for estimating wildlife population density. Since the usual approach assumes a model for the detection function, the estimate depends on the shape of such a function. In particular, the estimate is influenced by the so-called shoulder condition, which ensures that detection is nearly certain at small distances from the line transect. For instance, the half-normal model satisfies this condition, whereas the negative exponential model does not. The aim of this paper is to propose the exponential mixture model of the half-normal and the negative exponential in order to estimate the population density in the case where the shoulder condition is not guaranteed. Such a case study on Hooded crow is described in the paper.     

Modelling landscape effects on density-contact rate relationships of deer in eastern Alberta: Implications for chronic wasting disease

Managing wildlife diseases requires an understanding of disease transmission, which may be strongly affected by host population density and landscape features. Transmission models are typically fit from time-series disease prevalence data and modelled based on how the contact rate among hosts is affected by density, which is often assumed to be a linear (density-dependent transmission) or constant (frequency-dependent transmission) relationship. However, long-term time-series data is unavailable for emerging diseases, and this approach cannot account for independent effects of landscape. We developed a mechanistic model based on ecological data to empirically derive the contact rate-density relationship in white-tailed and mule deer in an enzootic region of chronic wasting disease (CWD) in Alberta, Canada and to determine whether it was affected by landscape. Using data collected from aerial surveys and GPS-telemetry, we developed empirical relationships predicting deer group size, home range size, and habitat selection to iteratively simulate deer distributions across a range of densities and landscapes. We calculated a relative measure of total per-capita contact rate, which is proportional to the number of other deer contacted per individual per unit time, for each distribution as the sum of pairwise contact rates between a target deer and all other individuals. Each pairwise contact rate was estimated from an empirical relationship developed from GPS-telemetry data predicting pairwise contact rates as a function of home range overlap and landscape structure. Total per-capita contact rates increased as a saturating function of density, supporting a transmission model intermediate between density- and frequency-dependent transmission. This pattern resulted from group sizes that reached an asymptote with increasing deer density, although this relationship was mediated by tree and shrub coverage in the landscape, such that in heavily wooded areas, the contact rate saturated at much lower densities. These results suggest that CWD management based on herd reductions, which require a density-dependent contact rate to be effective, may have variable effects on disease across a single management region. The novel mechanistic approach we employed for estimating effects of density and landscape on transmission is a powerful complement to typical data-fitting approaches for modelling disease transmission.     

The Conflict between Wildlife and Local People Living Adjacent to Protected Areas in Tanzania: Human Density as a Predictor

A questionnaire survey was conducted in Tanzania of 1396 local people living adjacent to Arusha, Kilimanjaro, Tarangire, Lake Manyara, and Mikumi National Parks and the Selous Game Reserve. Over 71% of local people surveyed reported problems with wildlife. The relative frequency of reported conflict with wildlife was significantly and inversely related to human density on lands adjacent to a protected area. Of those local people who reported having problems with wildlife, 86% reported crop damage, while 10% reported the killing of livestock and poultry. The problematic wildlife species also varied significantly with human density. Large animals were more problematic at low human densities, while small animals were more problematic at high human densities. Local people were generally less effective in controlling small-bodied species than large-bodied species. The relative frequency of reported success in controlling wildlife varied significantly with human density and was bimodal: local people were less effective in controlling wildlife at lower and higher human densities. This bimodal relationship suggests that, even if all protected areas in Tanzania were abolished, local people would continue to experience problems with wildlife at high human densities. To minimize the conflict between wildlife and local people, land uses associated with low human density that are non-attractive to wildlife should be encouraged on lands adjacent to protected areas in Tanzania.     

Should consumptive sustainable use of Sika Deer (Ceruus nippon) in Dilijan Reserve,NE Armenia be instituted?

SUMMARY

Numbers of sika deer (Ceruus nippon), resident in the Dilijan Reserve in 1969 (52 animals), 1970 (50), 1972 (1), and 1976 (28) dramatically increased in number until 1981, when the population reached a ceiling, being the number which can subsist in the area—300 individuals (density—11–12.5 deer per 1000 ha). Thus, Dilijan Reserve's C. nippon population develops in a way which resembles an S-like log curve equation.

Actually, Dilijan Reserve no longer has the status of a protected area—nowadays lumbering activities predominate and, inevitably, the unique broadleaf deciduous forest ecosystem will run down to extinction. Such economically valuable species as oak, beech, and sika deer are likely to be the first victims of this large-scale devastation.

The present article does not reject exploitation of any resource (including sika deer), if necessary. The key question is: how C. nippon can be sustainably utilized, so that the number of culled animals is replenished within the same year and and so that eventually the population size will remain constant?     

Emerging prion disease drives host selection in a wildlife population

Infectious diseases are increasingly recognized as an important force driving population dynamics, conservation biology, and natural selection in wildlife populations. Infectious agents have been implicated in the decline of small or endangered populations and may act to constrain population size, distribution, growth rates, or migration patterns. Further, diseases may provide selective pressures that shape the genetic diversity of populations or species. Thus, understanding disease dynamics and selective pressures from pathogens is crucial to understanding population processes, managing wildlife diseases, and conserving biological diversity. There is ample evidence that variation in the prion protein gene (PRNP) impacts host susceptibility to prion diseases. Still, little is known about how genetic differences might influence natural selection within wildlife populations. Here we link genetic variation with differential susceptibility of white-tailed deer to chronic wasting disease (CWD), with implications for fitness and disease-driven genetic selection. We developed a single nucleotide polymorphism (SNP) assay to efficiently genotype deer at the locus of interest (in the 96th codon of the PRNP gene). Then, using a Bayesian modeling approach, we found that the more susceptible genotype had over four times greater risk of CWD infection; and, once infected, deer with the resistant genotype survived 49% longer (8.25 more months). We used these epidemiological parameters in a multi-stage population matrix model to evaluate relative fitness based on genotype-specific population growth rates. The differences in disease infection and mortality rates allowed genetically resistant deer to achieve higher population growth and obtain a long-term fitness advantage, which translated into a selection coefficient of over 1% favoring the CWD-resistant genotype. This selective pressure suggests that the resistant allele could become dominant in the population within an evolutionarily short time frame. Our work provides a rare example of a quantifiable disease-driven selection process in a wildlife population, demonstrating the potential for infectious diseases to alter host populations. This will have direct bearing on the epidemiology, dynamics, and future trends in CWD transmission and spread. Understanding genotype-specific epidemiology will improve predictive models and inform management strategies for CWD-affected cervid populations.