Habitat heterogeneity as the key determinant of the abundance and habitat preference of prey species of tiger in the Chitwan National Park,Nepal

Studies on the relationship between habitat heterogeneity and animal abundance are essential for understanding what determines biodiversity. Transect-based direct observations of eight principal prey species of tiger in the Chitwan National Park (CNP) were used to determine their abundances and habitat preferences. Chital was the most abundant prey species of tiger (Panthera tigris). Each of the prey species had significantly different habitat preferences except sambar deer and chital. Habitat preference was measured using Manly’s preference index, which revealed that short grassland, mixed forest, and riverine forest were the most preferred habitats of the prey species. The results indicate that large species of deer tend to be found in more diverse habitats than small species, except muntjac. The abundance of the principal prey species of tiger was positively correlated with habitat heterogeneity. The habitat, which contributes significantly to the heterogeneity of the landscape, is grassland in large patches of forest. The ongoing increase of forest cover in the CNP has led to a reduction in the area of grassland, which may negatively affect the abundance of the prey species of tiger. Hence, it is suggested that the restoration of landscape heterogeneity is the best way to manage the habitats in the CNP.     

Spatial variation in the density and vulnerability of preferred prey in the landscape shape patterns of Amur tiger habitat use

Theoretical and empirical research suggests that carnivore distributions are largely determined by prey availability. Availability depends not only on prey density but also on prey accessibility which is affected, in part, by the configuration of landscape attributes that make prey vulnerable to predation. Exactly how spatial variation in these processes shape patterns of carnivore habitat use at the home range scale remains poorly understood. We examined the influence of prey density (negative binomial resource selection function) and vulnerability (kill site resource selection function), mapped separately for each of three species of primary prey, on habitat use patterns within the home range for Amur tigers Panthera tigris altaica in Far East Russia over 20 winters. We developed spatially‐explicit mixed linear regression models to assess these patterns and found that models with parameters for specific primary prey were more robust than models with composite parameters for all primary prey species. This emphasizes the importance of evaluating predation dynamics at a species‐specific level. We also found that Amur tigers used habitat within the home range where red deer Cervus elaphus and wild boar Sus scrofa were dense. These two species were clearly preferred by tigers accounting for 72% (201 of the 278) of the tiger kills detected. The effect of red deer density however, was modulated by the vulnerability of red deer in the landscape. Amur tigers tended to establish their home ranges on habitat where red deer were most vulnerable to predation, but would use habitat where red deer were dense in the peripheral regions of their home ranges. This suggests that tigers may utilize two separate strategies for acquiring prey. As the configuration of resource patches within the home range influences carnivore survival and reproduction, our analysis has implications for tiger conservation that extend beyond our improved understanding of tiger‐prey ecology.     

老爷岭南部狍冬季移动、卧息生境选择及其适宜性评价

在动物生境研究中,移动生境和卧息生境是生境研究的焦点。开展移动生境和卧息生境选择,并在此基础上进行生境评价,有利于深入了解动物对移动和卧息生境条件的需求,制定科学合理的栖息地保护计划。以东北虎（Panthera tigris altaica）的主要猎物物种之一-狍（Capreolus pygargus）为研究对象,于2017-2019年冬季积雪覆盖期在老爷岭南部通过随机布设28个大样方和84条用于足迹链跟踪的样线收集狍的移动点和卧息点信息,再结合近年来收集的东北虎出现点,利用广义可加模型（GAM）和最大熵模型（MaxEnt）进行狍移动、卧息生境选择及评价研究。移动生境选择研究表明,狍在移动的过程中偏好选择坡度小、距农田距离>500 m、远离道路、居民点和低海拔或较高海拔的区域;移动生境评价分析表明,移动适宜和次适宜生境面积之和为1318.16 km²,占研究区域面积的51.28%,当加入虎活动点影响因子后,狍移动适宜和次适宜生境面积之和为901.52 km²,适宜和次适宜生境面积之和减少了31.61%。狍卧息生境选择研究表明,水源、农田、道路和雪深是影响狍卧息的关键因素,其中雪深对狍卧息生境选择的贡献率达到70.13%;卧息生境评价表明,卧息适宜和次适宜生境面积之和为1243.77 km²,占研究区域面积的48.39%,当加入虎出现点因子后,适宜生境和次适宜生境面积之和减少了61.00%,仅为485.02 km²。研究认为,虎的出现对狍移动和卧息生境选择均产生影响,虎的活动及捕食行为可能会减少狍的活动范围和频次,狍远离虎活动区域卧息休息,压缩了狍适宜卧息的空间。     

黑龙江省东完达山地区东北虎猎物种群现状及动态趋势

猎物种群丰度是限制虎分布和数量的关键因子,因此猎物种群密度监测和估算是虎保护的重要内容之一。应用采用大样方法,地理信息系统技术和多元统计分析,研究了黑龙江东完达山东部地区东北虎猎物种群(马鹿、狍子和野猪)现状及动态变化趋势。结果表明:研究地区马鹿的种群平均密度为(0.2010±0.0270)只/km²、狍子的平均种群密度为(0.4980±0.0436)只/km²、野猪的平均种群密度为(0.3423±0.0275)只/km²。单因素方差分析表明,在相同生境下,3种有蹄类密度在在阔叶混交林中和杂木林中差异极为显著;不同的生境,3种猎物的猎物的密度也存在着显著差异。相关分析表明马鹿密度和野猪密度程正相关,而马鹿密度和狍子密度、狍子密度和野猪密度则不相关。 同1989年该地区东北虎猎物种群相比:1989-2002年的13 a时间内马鹿的年平均递减率为13.48%、狍子的年平均递减率为12.69%、野猪的年平均递减率为1.89%。     

Estimating red deer abundance in a wide range of management situations in Mediterranean habitats

When human interventions interfere with the natural regulation of wildlife populations by favouring some species, overabundance can emerge. We evaluated different methods of estimating red deer abundance in a wide range of population densities from southern Spain. Distance sampling estimates were used as the reference method across 22 localities and were compared with two kilometric abundance indices (KAIs), four indices based on pellet group counts and two browsing indices (BWIs). The average red deer density estimated by distance sampling was 19.51±3.19 deer per 100 ha, showing a wide range across the study area (0.04–66.77). Distance sampling estimates correlated with the KAIs, pellet group-based index and the BWI. The agreement with distance sampling improved when groups were used instead of individuals in the KAIs, when the minimum pellet group size was fixed at 20 pellets in the dropping counts, and when only highly palatable species were used in the BWI. Thus, several direct and indirect methods can estimate red deer abundance in Mediterranean habitats from Southern Spain with appropriate modifications.     

黑龙江省完达山东部林区东北虎猎物生物量

研究一个地区猎物种群生物量能否满足捕食动物种群数量的需求,这对于了解濒危大型食肉动物是否受到来自于食物缺乏的威胁和制定相应的保护措施极其重要。为了掌握黑龙江省完达山东部林区东北虎食物需求与猎物生物量之间的关系,于2008年冬季至2009早春积雪覆盖期采用随机布设样线,通过收集有蹄类动物在雪地上留下的足迹等活动的方法,在东方红林业局和迎春林业局管辖境内3 692.06 km²的区域布设大样方48个,并在大样方里共布设样线240条开展有蹄类动物种群数量调查,确定东北虎猎物生物量。调查结果表明:研究地区野猪(成体502 606只,亚成体209 210只)、马鹿(成体331 357只,亚成体67 72只)和狍子(成体810 815只,亚成体202 203只)的生物量分别为74 767.50 87 825.00 kg、79 744.50 85 984.50 kg 和 31 337.00 31 525.50 kg,3种有蹄类动物生物量共计1 85 849.00 205 335.00 kg。研究地区猎物总生物量为209 619.89 231 598.24 kg。如果按8%的生物提供给东北虎,3种主要猎物生物量可满足5.22 6.92只东北虎个体的食物需求,研究地区猎物总生物量则可满足5.89 7.81只东北虎个体的食物需求。此外,对足迹遇见率与抽样强度、抽样强度与足迹遇见率的均值标准误差之间关系的分析表明,在完达山东部林区布设120条样线(抽样距离600 km)、150条样线(抽样距离750 km)和115条样线(抽样距离675 km)能满足野猪、马鹿、狍子种群数量调查准确性的最低需求。     

Spatial and temporal habitat use and selection by red deer: The use of direct and indirect methods

Given the importance of red deer Cervus elaphus for hunting and conservation purposes, understanding the interactions between this species and its habitats in the Mediterranean region is a crucial step for the sustainable management of this species. Aiming to compare pellet group counts and direct observations methods to study the habitat use and selection by red deer, the results obtained by both methods were compared, and their advantages and disadvantages were discussed. To understand the temporal patterns of habitat use and selection, the survey was conducted at three different seasons, birth period, rut season and winter. The habitat use and selection were studied in relation to land cover, watercourse, roads, ecotone zones and other topographic features (altitude, slope and aspect), using generalized linear models and selection ratios. The similarity of the results provided by pellet group counts and direct observations indicate that both methods may constitute useful tools to study the habitat use and selection by red deer. Globally, red deer seemed to select habitats that provide simultaneously food and some cover, as shown by its preference for shrublands, independently of the sampling season. The positive selection of ecotone zones embodies the need for open spaces. Males and females showed a similar use of shrubland, but selected patches with different characteristics therein. The spatial and temporal patterns exhibited by our results suggest that red deer balance their habitat requirements in respect to each phase of their reproductive cycle. Pellet group counts and direct observations seem to be useful methods to analyze habitat use and selection, and may provide helpful knowledge to the management and conservation of red deer.     

Distance sampling techniques compared for a New Zealand endemic passerine (

The effectiveness of line- and point-transect distance sampling methods was compared for estimating the density of a conspicuous endemic passerine, the North Island saddleback Philesturnus carunculatus rufusater, in two forest habitats on Tiritiri Matangi Island, Hauraki Gulf, New Zealand. The reference population abundance in each habitat was calculated through an intensive capture, colour-banding, and resighting effort. Line transects consistently produced unbiased estimates of density for both sites at two time periods (morning and afternoon), and proved to be the most efficient of the distance sampling methods tested. Point-transect methods proved to be biased in this instance, consistently producing overestimates of density for this species, and were unreliable as indices of the small differences in density between habitats. Transect counts conducted from established walking tracks underestimated both density and the variance of estimated density. We conclude that in situations requiring estimates of absolute density for North Island saddleback, a series of randomly positioned line transects will accurately represent the density of individuals. Furthermore, this study highlights the need to pilot distance survey techniques on the species of interest to detect possible violation of the assumptions underlying these methods. We question the widespread use of point-transect counts for censusing avian species without such preliminary investigation, and recommend further comparisons of distance sampling methods in New Zealand with reference populations where opportunity provides.     

Distance models as a tool for modelling detection probability and density of native bumblebees

Effective monitoring of native bee populations requires accurate estimates of population size and relative abundance among habitats. Current bee survey methods, such as netting or pan trapping, may be adequate for a variety of study objectives but are limited by a failure to account for imperfect detection. Biases due to imperfect detection could result in inaccurate abundance estimates or erroneous insights about the response of bees to different environments. To gauge the potential biases of currently employed survey methods, we compared abundance estimates of bumblebees (Bombus spp.) derived from hierarchical distance sampling models (HDS) to bumblebee counts collected from fixed‐area net surveys (“net counts”) and fixed‐width transect counts (“transect counts”) at 47 early‐successional forest patches in Pennsylvania. Our HDS models indicated that detection probabilities of Bombus spp. were imperfect and varied with survey‐ and site‐covariates. Despite being conspicuous, Bombus spp. were not reliably detected beyond 5 m. Habitat associations of Bombus spp. density were similar across methods, but the strength of association with shrub cover differed between HDS and net counts. Additionally, net counts suggested sites with more grass hosted higher Bombus spp. densities whereas HDS suggested that grass cover was associated with higher detection probability but not Bombus spp. density. Density estimates generated from net counts and transect counts were 80%–89% lower than estimates generated from distance sampling. Our findings suggest that distance modelling provides a reliable method to assess Bombus spp. density and habitat associations, while accounting for imperfect detection caused by distance from observer, vegetation structure, and survey covariates. However, detection/non‐detection data collected via point‐counts, line‐transects and distance sampling for Bombus spp. are unlikely to yield species‐specific density estimates unless individuals can be identified by sight, without capture. Our results will be useful for informing the design of monitoring programs for Bombus spp. and other pollinators.     

Long-term density-dependent changes in habitat selection in red deer (Cervus elaphus)

Understanding how habitat selection changes with population density is a key concept in population regulation, community composition and managing impacts on biodiversity and ecosystem services. At low density, it is expected that individuals select habitats in terms of their preference, but as population density increases, the availability of resources per individual declines on preferred habitats, leading to competition which forces some individuals to exploit less preferred habitats. Using spatial information of Scottish red deer (Cervus elaphus) winter counts, carried out in 110 areas across Scotland between 1961 and 2004 (a total of 1,206,495 deer observations), we showed how winter habitat niche breadth in red deer has widened with increasing population density. Heather moorland and montane habitats were most and least preferred for deer, respectively. Increasing density favoured the selection of grassland, to the detriment of the selection of heather moorland. The selection of heather and grassland decreased when temperature increased, while the selection of montane and peatland habitats increased. These findings are important for understanding how habitat use, density and population are likely to be affected by weather, and allow us to predict habitat impacts by large mammal herbivory and climate.     

Estimating occupancy of the Vulnerable northern tiger cat <Emphasis Type="Italic">Leopardus tigrinus</Emphasis> in Caatinga drylands

Understanding the distribution and habitat preference of threatened species is essential for their conservation. We conducted the first systematic camera trap survey of the Vulnerable northern tiger cat Leopardus tigrinus in Caatinga drylands (Brazil) and tested how its occupancy and detectability patterns are affected by environmental and anthropogenic factors. Species detection-non-detection data, obtained by 7263 camera-days distributed throughout 187 sampling sites on ten Caatinga landscapes, were used to evaluate species detectability and occupancy according to ten environmental and anthropogenic predictors. We built seven detection models and 30 hierarchical occupancy models that have been ranked based on the Akaike Information Criterion. The estimated average occupancy of 0.46 was 38% higher than the naïve occupancy rate (0.34). Species occupancy was higher in locations with greater forest cover and at greater distance to agrarian settlements. Hunting and persecution of northern tiger cats by residents and a possible reduction of their natural prey by hunting may explain the result. On the contrary, more forested environments may represent higher-quality habitats providing greater availability of prey and shelters and protection against anthropogenic threats and extreme temperatures. These results improve the understanding of the ecology of a threatened and poorly known small cat, and they can guide conservation actions such as the creation of dense forest protected areas and provide information for mitigating human-carnivore conflict.     

Estimating density of Kirk’s dik‐dik (Madoqua kirkii Günther), impala (Aepyceros melampus Lichtenstein) and common zebra (Equus burchelli Gray) at Mpala,Laikipia District,Kenya

This study compares two methods of estimating the density of three ungulate species: Kirk’s dik‐dik, impala and common zebra, in a dry savannah ecosystem. Fixed strip width and distance sampling involving direct animal counts were used in parallel, and tested for bias and precision in two habitats. Distance sampling was the method that achieved a better balance between accuracy and precision. The differences in sightability of ungulates, according to body size, colour and habitat characteristics, are taken into account by the distance sampling method, but not by the strip method, which produced, what we suspect are, underestimates of animal density.     

Habitat use,abundance, and persistence of Neotropical migrant birds in a habitat matrix in northeast Belize

ABSTRACT To ensure adequate protection of nonbreeding habitats used by Neotropical migratory landbirds, we must first address questions about habitat use and quality. On the Yucatan peninsula, migrants use many habitats, several of which remain unstudied, and methodological differences preclude interhabitat comparisons based on studies to date. We used distance sampling along line transects in six habitats in northeast Belize to examine use of previously unstudied habitats (e.g., salt marsh) by Neotropical migrants and to permit comparison across habitats. We calculated unadjusted and adjusted (for detectability) density estimates for individual migrant species and for all species combined to generate hypotheses about habitat quality based on the assumption that density and quality are positively correlated. Adjusted density estimates for all migrants were highest in black mangrove habitat (1799 ± 110 ind/km²), intermediate in three forest types and milpa (range 598–802 ind/km²), and lowest in salt marsh (207 ± 32.3 ind/km²). By combining density estimates with habitat availability in our study region, we estimated that evergreen forest and black mangrove supported 70% and 9% of the region's migrant population, respectively. At the species level, five of the 10 most common species had habitat preferences (>50% detections in one habitat). Given the diversity of habitat preferences among species and apparent seasonal movements, our results indicate that Neotropical migrants in northeast Belize are dependent on a matrix of interconnected habitats.     

张广才岭南部东北虎猎物种群冬季营养容纳量研究

猎物匮乏是影响东北虎（Panthera tigris altaica）种群恢复的关键因素之一。容纳量研究是开展东北虎猎物恢复工作的必要前提。通过Maxent模型、聚类分析和训练随机树分类等方法,结合调查数据,预测了吉林省张广才岭南部黄泥河林业局东北虎主要猎物的适宜栖息地空间分布,解译了植被类型,在此基础上基于不同植被类型动物可采食部分代谢能、不同生境等级食物可利用率、马鹿（Cervus elaphus）和狍（Capreolus capreolus）生境等级重叠情况以及动物冬季能量需求,分析了东北虎猎物的冬季营养容纳量。结果表明：黄泥河林业局狍、野猪（Sus scrofa）和马鹿的适宜栖息地分别占研究区域总面积的52.8%、40.7%和25.4%;从猎物获取能量来看,以山杨（Populus davidiana）、桦树（Betula）、核桃楸（Juglans mandshurica）为主的植被类型是马鹿、狍可获得能量较多的生境,以蒙古栎（Quercus mongolica）、核桃楸为主的植被类型是野猪可获得能量较多的生境。东北虎猎物种群的综合冬季营养容纳量为574只马鹿（0.29只/km²）,7016只狍（3.54只/km²）,4785只野猪（2.38只/km²）。     

Prey habitat selection under shared predation: tradeoffs between risk and competition?

An individual's choice of habitat should optimize amongst conflicting demands in a way that maximizes its fitness. Habitat selection by one species will often be influenced by presence and abundance of competitors that interact directly and indirectly with each other (such as through shared predators). The optimal habitat choice will thus depend on competition for resources by other species that can also modify predation risk. It may be possible to disentangle these two effects with careful analysis of density‐dependent habitat selection by a focal prey species. We tested this conjecture by calculating habitat isodars (graphs of density assuming ideal habitat selection) of chital deer living in two adjoining dry‐forest habitats in Gir National Park and Sanctuary, western India. The habitats differed only in presence (Sanctuary) and absence (National Park) of domestic prey (cattle and buffalo). Both species are preyed on by Asiatic lions. The habitat isodar revealed at low densities, that chital live in small groups and prefer habitat co‐occupied by livestock that reduce food resources, but also reduce predation risk. At higher densities, chital form larger groups and switch their preference toward risky habitat without livestock. The switch in chital habitat use is consistent with theories predicting that prey species should trade off safety in favor of food as population density increases.     

Patterns of habitat and invertebrate diet overlap between tiger salamanders and ducks in prairie potholes

During the breeding season, migratory waterfowl are attracted to wetlands characterized by high macroinvertebrate availability. Many of these prairie potholes are fishless and this apparent void is filled, at least partially, by tiger salamanders. Based on gut contents from 98 tiger salamanders and published diet data from over 1500 ducks, we show that there is general overlap in diet between both larval and adult tiger salamanders and 10 duck species. Furthermore, when the ducks were split into foraging guilds and compared with tiger salamanders, prey type overlap was 1.7 times higher and prey size was 1.8 times higher with dabbling ducks than diving ducks. Field surveys show that tiger salamander density is more highly correlated with diving duck density across potholes than dabbling duck density. Tiger salamanders have higher diet overlap with dabbling ducks than diving ducks whereas tiger salamanders have higher spatial overlap with diving ducks than dabbling ducks suggesting that these consumers coarsely partition diet and habitat resources. It has been reported that tiger salamanders have specialized diets that are associated with foraging preferences for benthic habitats. This view is too narrow: in southwestern Manitoba, Canada, tiger salamanders are more general consumers with diets more like dabbling ducks that forage mostly in planktonic and littoral habitats. Our results suggest that dabbling and diving ducks are, to different extents, liable to the effects of indirect interactions, specifically competition for common prey, with tiger salamanders.     

Breaking Dawn: Factors influencing mammalian habitat usage in western Assam following socio-political instability

The impacts of conflict on nature are devastatingly adverse but differ widely in different socio-economic-political regimes. Armed conflict often facilitates illegal plunder and unsustainable use of natural resources. We studied the response of mammals in Ripu (605.27 sq.km, westernmost part of Manas Tiger Reserve) Reserved Forest (RF) in Assam, India that suffers prolonged anthropogenic pressures due to armed conflict instigated by social unrest. We used standard single-season occupancy models using sign survey to assess factors affecting the space use of mammals. Our study revealed that Ripu RF has a high proportion of area occupied by prey species of large carnivores. Asian elephant, barking deer, and wild pig occupied most of the habitat, whereas gaur, sambar and spotted deer restricted themselves to selected patches. The probability of a site being occupied by the majority of ungulates declines with an increase in anthropogenic activities, including distance to human settlement (measure of prolonged disturbance) and an increase in the proportion of secondary degraded forest. Common leopard was found to be positively associated with prey occupancy and increase in semievergreen and moist-mixed deciduous forest. Our ground efforts to strengthen community patrolling and operational execution of various alternative livelihoods has helped to improve the economic condition of patrolling staff. Strategic implementation of law enforcement could support dispersal of tigers from Phibsoo Wildlife Sanctuary (Bhutan), potentially linked to the larger tiger and elephant landscape far west (Buxa Tiger Reserve in West Bengal) in the Terai region of India. Various community-based conservation initiatives and strategies with sustained support from various agencies, including national, international, and local bodies, is required to restore this critical habitat.     

Temporal variation in habitat selection breaks the catch‐22 of spatially contrasting predation risk from multiple predators

Predator avoidance depends on prey being able to discern how risk varies in space and time, but this is made considerably more complicated if risk is simultaneously present from multiple predators. This is the situation for an increasing number of mammalian prey species, as large carnivores recover or are reintroduced in ecosystems on several continents. Roe deer Capreolus capreolus in southern Norway illustrate a case in which prey face two predators with contrasting patterns of predation risk. They face a catch‐22 situation: spatially avoiding the risk from one predator (lynx Lynx lynx in dense habitat) implies exposure to the other (hunters in open habitat). Using GPS‐data from 29 roe deer, we tested for daily and seasonal variation in roe deer selection for habitat with respect to the habitats’ year‐round average risk level. Generally, roe deer altered their habitat selection between night and day in a pattern consistent with being able to avoid predicted risk from the nocturnal lynx during night and predicted risk from human hunters during day. However, seasonal variation in habitat selection only partially corresponded with the predicted seasonal variation in risk. Whereas roe deer avoided areas with high risk from hunters more strongly during the hunting season than in other seasons, there was a lack of selection towards areas and time periods lowering the risk of lynx predation during winter. It seems likely that the risk of starvation and thermal stress constrain roe deer habitat selection during this energetically challenging season with cold temperatures, snow cover and limited natural forage. The habitat selection pattern of roe deer fits thus only partly with the two contrasting risk gradients they face. Adjusting risk‐avoidance behavior temporally can be an adaptive response in the case of several predators whose predation patterns differ in space and time.     

Dietary preference of cheetahs (Acinonyx jubatus) in south‐eastern Kenya

The conversion of natural ecosystems due to anthropogenic activities has led to the destruction of natural habitats and to the deterioration of habitat quality. Top predators particularly respond sensitively to changes in habitat structures, including the availability of prey. The cheetah Acinonyx jubatus prefers small‐medium‐sized, wild ungulate prey due to the cheetah''s morphological adaptations. However, the majority of the species’ population is found beyond protected areas, where habitat structures, species abundances, and community composition are highly influenced by human activities. Only few studies have analyzed the diet preference of cheetahs in relation to prey availability and abundance for rangelands beyond protected areas in Eastern Africa. The study aimed to determine cheetah prey preference in the rangelands of south‐eastern Kenya based on scat analyses. We compared dietary preference of cheetah with prey availability. For this purpose, we conducted standardized game counts. We analyzed 27 cheetah scat samples collected across the same study area where we also conducted game counts. We found that Grant''s gazelle Gazella granti contributed the highest portion of cheetah''s diet, although Thomson''s gazelle Gazella thomsonii was the most abundant medium‐sized ungulate prey in the study areas. We also recorded two primate species, yellow baboon Papio cynocephalus and vervet monkey Chlorocebus pygerythrus, as well as the rock hyrax Procavia capensis in the cheetah diet. These species have never been documented as cheetah prey before. Furthermore, our results document livestock as potential prey for cheetahs. These observations underline that cheetah use diverse prey in rangelands outside protected areas, and that the abundance of specific prey does not influence cheetah prey preference.     

Habitat occurrence and prey distribution of a multi-species community of shrews in the Siberian taiga

The habitat occurrence and invertebrate prey distribution of nine species of shrew in the mid-taiga of central Siberia were investigated. Species richness ranged from 4–9 shrews per habitat. Sorex araneus and S. caecutiens were numerically dominant in all seven habitats (44 and 36% of the total catch, respectively) while Sorex minutus, S. tundrensis, S. isodon , and S. roboratus each constituted 4–6% and Sorex minutissimus, S. daphaenodon , and Neomys fodiens were rare (< 1% each). There was no overall correlation between abundance of shrews and invertebrate prey, but flood-plain habitats supported the greatest abundance and species richness of shrews, and high density and biomass of prey. Oligochaete-eating shrews were twice as numerous here as in other habitats, coincident with high abundance of oligochaetes. The large, earthworm-feeding Sorex roboratus occurred only here. The more acid, typical taiga habitats had lower adundance and species richness of shrews. They had the lowest density and biomass of prey, particularly oligochaetes, and far fewer oligochaete-eating shrews. The relative paucity of shrews in bush-meadow habitats, despite abundant prey, implied that habitat structure influences shrew distribution. Differential numbers of certain species in the presence or absence of larger congeners also suggested that interspecific competitive effects influence habitat selection by shrews. The high species richness of shrews here in the mid-taiga may be accounted for by the heterogeneous nature of the constituent habitats which provide niches for small and large species of shrew with a range of feeding habits.