野放普氏野马(Equus przewalskii)家域面积及其影响因素

采用MCP方法研究了2011年至2012年新疆卡拉麦里山有蹄类自然保护区野放普氏野马家域的变化。通过方差分析验证了年间、季节间不同群体家域及其两两重叠无差异。以家族群大小为协变量进行了野放野马家域协方差分析。利用野放野马家族大小为协变量的协方差分析分析检验了野放野马家族大小与家域关系。结果表明:(1)野马平均家域面积由2011年的(20±2)km~2/匹扩大到2012年的(30±2)km~2/匹。对部分野放群体中头马未发生更替的野马群的研究表明,随着野马群体增大,其家域面积显著增大(P0.05)。(2)单因素方差分析显示,不同野马群的家域面积在不同年份差异显著,且春季家域秋季家域夏季家域。(3)2011年不同群家域两两间相互重叠面积与群大小无显著相关(r=0.256,P=0.5800.05)。而2012年野马群家域两两之间重叠面积有显著差异(F=4.521,df=8,P0.001)。家域两两相互重叠面积与群大小显著相关(r=0.706,P=0.0330.05)。(4)不同季节间野马群家域重叠面积有显著差异(F=5.695,df=8,P0.001)。5号群、7号群和8号群的自身家域重叠面积(P0.05),3号群、6号群和9号群的家域重叠面积(P0.05)。(5)影响野放野马家域面积的生物因子有草本盖度、灌木盖度,非生物因子主要有温度、湿度、风速、最近水源地距离和最近居民点距离等。温度与草本盖度是影响野放野马家域面积大小的主要因素,两者与野放野马家域面积显著相关(P0.01)。     

青海省都兰县藏狐家域范围及重叠度

2006年9月21日至10月21日、2007年1月14～20日、2月6～12日和3月13日至4月8日,应用无线电追踪技术对青海省都兰县沟里乡3只藏狐(2雄,1雌)进行追踪定位,采用Kernel方法计算了3只藏狐的家域面积,确定了该物种的核域,并探讨了不同藏狐个体间家域及核域的重叠状况.结果表明,沟里乡藏狐平均家域面积为6.4±0.4 km2,平均核域面积为1.6±0.2 km2,核域约占家域总面积的1/5～1/4.3只藏狐总体家域面积相差不大,藏狐家域及核域均有一定程度的重叠,家域重叠程度约为50%～60%,核域重叠程度则远远减小,约为7%～20%.     

罗布泊野骆驼的家域特征及其意义

野双峰骆驼(Camelus ferus)生活在荒漠戈壁, 种群数量稀少, 栖息地地形复杂多样, 且有长距离迁徙习性, 目前对其家域面积和重要栖息地范围的研究只有定性描述。本研究于2012年5月至2013年7月, 在阿奇克谷地和阿尔金山北麓捕捉了8峰野骆驼并安装GPS卫星跟踪项圈, 分别获得了12-423天的13,748个GPS位点记录。研究结果表明, 8峰野骆驼的100%最小凸多边形(minimum convex polygons, MCP)家域面积分别为1,775-11,768 km², 总家域面积为32,821 km², 占罗布泊野骆驼分布区面积的23.1%, 平均家域面积为7,349 ± 1,323 km²。野骆驼个体家域面积季节间差异显著, 秋季最大, 其次是冬季和夏季, 春季最小, 秋季是春季的4.4倍。野骆驼在繁殖季节的家域平均面积为879 ± 320 km², 非繁殖季节为998 ± 106 km², 二者间无显著差异。除了项圈编码为135号的野骆驼和其他7峰野骆驼的家域没有重叠外, 其余7峰野骆驼的家域都有重叠。这7峰野骆驼的家域总面积是24,910 km², 占罗布泊野骆驼分布区总面积的17.5%, 重叠区面积是515 km²。鉴于野骆驼主要分布在阿奇克谷地及以南区域、阿尔金山北麓, 建议将罗布泊野骆驼国家级自然保护区位于阿奇克谷地北山以北的核心区部分区域、磁海低地以南的山区和阿尔金山西部原为实验区的部分区域调整为缓冲区, 而将阿尔金山北麓至库姆塔格沙漠之间的戈壁地带原为缓冲区的部分区域调整为核心区。     

小兴安岭南坡野猪家域分析

采用笼式活捕野猪,利用无线电遥测技术、R2V、Arcview 和SPSS 软件技术,于2004 年7 月15 日至2006年1 月19 日,对小兴安岭南坡野猪家域进行测定、计算和分析,以了解该地区野猪的家域变化规律。研究结果表明:季节变化影响野猪家域面积,在春、秋季,野猪的家域面积显著大于冬季,而春、夏季间无显著差异;不同性别及年龄野猪家域大小也不同,成体雄性秋季发情期和亚成体春季分窝期家域面积显著增加;在冬、春季家族群野猪的家域面积显著大于独体野猪家域面积,说明家族群对家域面积有影响;亚成体家域大小主要受家族群家域的影响,家族群野猪面积大,相应地家族野猪中亚成体家域面积也大。     

海南文昌昌洒荒坡地生境中蜡皮蜥繁殖期家域

为掌握蜡皮蜥(Leiolepis reevesii)繁殖期家域大小、家域内是否存在核域,以及家域与核域的重叠程度,分别于2010年和2011年的3月至5月在海南文昌荒坡地生境中,应用无线电遥测技术对蜡皮蜥家域进行了研究,采用最小凸多边形、固定核域、线家域等方法分析了13只个体(10雄3雌)的家域、核域及其重叠度。雄性最小凸多边形(100%MCP)家域面积为(14 091.6±5 718.0)m2,显著大于雌性的(253.3±106.5)m2(t=4.064,df=11,P=0.002);雄性95%固定核域(FK)和75%FK面积为(10 707.8±2 388.5)m2和(3 282.7±1 022.8)m2,分别显著大于雌性的(379.1±74.1)m2(t=7.262,df=11,P0.001)和(172.1±37.9)m2(t=5.107,df=11,P0.001);雄性线家域为(205.8±52.5)m,显著大于雌性的(25.0±2.0)m(t=5.781,df=11,P=0.034);分析遥测个体位点利用方式,蜡皮蜥个体家域内核域明显,雄性核域为(1 380.5±429.1)m2,显著大于雌性的(80.2±18.5)m2(t=5.088,df=11,P0.001),且雄性核域占100%最小凸多边形家域面积的比例为10.9%±3.9%,显著低于雌性的33.3%±6.1%(t=﹣7.834,df=11,P0.001);雄性100%MCP面积不仅与头体长(SVL)之间线性相关显著(n=10,r=0.815,P=0.004),而且与体重(BM)之间也具有明显的线性相关(n=10,r=0.683,P=0.029);个体之间具有家域和核域重叠,雄性个体之间100%MCP家域重叠指数为0.26±0.17,显著低于雌性的0.66±0.02(t=﹣3.372,df=34,P=0.002),而雄性核域重叠面积占核域比例为2.50%±1.70%、重叠指数为0.02±0.02,雌性比例为0.34%±0.01%、重叠指数为0.01,表明蜡皮蜥具有明显的领域性,且雌性在繁殖季节其领域性明显高于雄性。     

城市公园中赤腹松鼠的家域特征及昼间活动规律初探

2015年12月至2016年5月,对上海动物园内活动的9只赤腹松鼠进行无线电遥测,应用Homing法进行空间定位,基于最小凸多边形（MCP）和95%固定 核空间（95%Kernel）模型估算城市绿地中赤腹松鼠的家域面积、空间分布特征及个体间的重叠情况,同时记录赤腹松鼠的昼间行为规律。赤腹松鼠 家域面积平均值为12376（MCP）~18146 m²（95%Kernel）,雌雄个体间家域面积无显著差异（Independent-sample test,t= -0.101,P=0.922）。 赤腹松鼠冬季家域面积与春季家域面积间无显著差异（One way ANOVA,MCP：F=3.900,P=0.070;95%FK：F=3.566,P=0.081）。部分赤腹松鼠家域 间存在重叠,冬季重叠指数0.36~0.63,春季重叠指数0.02~0.43。赤腹松鼠的昼间行为以移动（29.4%）、取食（25.1%）和休息行为（24.7%）为主 。在不同季节,赤腹松鼠的取食行为发生显著变化（One way ANOVA,F=119.268,P<0.001）,冬季取食行为发生频率最高（33.3%）,夏季最低 （16.4%）;领域行为在夏（15.8%）、秋（16.2%）季发生频率较高,春季（5.8%）降低（One way ANOVA,F=140.416,P<0.001）。赤腹松鼠昼间 活动呈“U”型分布,主要集中于05:00—08:00和15:00—18:00,休息主要分布于12:00—13:00。     

地形因素对羚牛家域估算的影响分析——以固定核域法与最小凸边形法为例

家域特征对物种基础生物学的认识和提出相关管理及保护对策有重要作用.本研究利用地理信息系统相关软件,以4只(2♀、2 ♂)佩戴GPS无线电颈圈的四川羚牛定位数据使用固定核域法(FKE)和最小凸多边形法(MEP)对春季(2007年和2008年)家域特征进行了估算,显示地形因素对家域估算结果影响显著,表面家域(FKE 95％ =7.50 ±2.27,MCP =7.01±1.99)要显著大于平面家域(FKE 95％=5.94±1.54,t=3.31,df=3,P=0.045,MCP=5.47±1.52,df=3,t=3.43,P=0.041).其次,固定核域法(95％)与最小凸多边形法所获得的平面家域(t =0.718,df=3,P=0.524)和表面家域(t=0.612,df=3,P=0.584)差异不显著.个体间家域差异显著(df=3,F=7.226,P=0.001),组间两两比较显示,M1与F1 (P =0.001)、F2(p=0.031)、M2(P=0.02),F1与F2 (P =0.044)间的家域均有显著差异,而M2与F2 (P =0.221)、M2与F1(P=0.598)间差异不显著.两种家域估算方法对计算羚牛的家域重叠程度没有明显优劣之分(95％ Kernel VS 100％ MCP),但不同密度的核域可能得出不同的甚至是完全相反的结论,因此在选择核域密度时应尽量同时参照其他数据和其他估算方法.     

库木塔格沙漠地区野骆驼活动节律与家域特征

野生双峰驼(Camelus ferus)生存于中亚沙漠腹地, 是国家I级重点保护野生动物。为探究野骆驼活动节律和家域状况, 了解其时间和空间尺度上的活动模式, 为其有效保护管理提供支持。本研究于2012年5月至2013年7月利用GPS跟踪项圈先后对库木塔格沙漠地区7峰野骆驼进行轨迹跟踪。利用跟踪数据对野骆驼活动节律进行分析, 并采用布朗桥模型对野骆驼家域进行分析。结果表明: (1)野骆驼日活动节律呈现明显双峰模式, 属晨昏活动类型, 活动高峰期主要出现于上午6:00-9:00及下午15:00-20:00。(2)野骆驼晨昏活动高峰存在明显的季节性变动, 双峰从暖季到冷季向中午移动, 按间隔时间长短排序为: 夏季 > 春季 > 秋季 > 冬季。(3)野骆驼日活动强度有明显的季节性差异, 大小关系为: 夏季 > 秋季 > 春季和冬季, 春季和冬季间差异不显著。(4)野骆驼为核心家域利用类型, 且存在多个核心家域, 一些野骆驼家域分布于沙漠南北两侧, 意味着其具有横跨沙漠的运动能力。(5)野骆驼个体间家域面积差异显著, 性别间家域面积差异不显著。季节间家域面积差异显著, 从大到小排序为: 夏季(1,256.27 ± 427.45 km²) > 春季(556.90 ± 259.35 km²) > 秋季(396.77 ± 82.31 km²) > 冬季(250.83 ± 99.64 km²)。     

不同色型棕背伯劳的冬季家域对比研究

棕背伯劳Lanius schach具有典型的羽色多态现象.于2008年11月14日至12月24日,采用野外直接观察法,利用GPS存取地理坐标点信息,对广东海丰鸟类自然保护区公平保护站黑、棕两种色型棕背伯劳家域进行对比研究,所得数据利用Arcview3.2和SPSS13.0软件技术分析,以探讨不同色型间在家域行为的差异.结果表明:(1)黑、棕两种色型棕背伯劳家域的平均面积分别为11270.96 m2±1807.72 m2、13425.83 m2±3038.82 m2,两者之间无显著差异(P>0.05);(2)被调查个体的家域形状均不规则,相邻家域间的重叠幅度均<1%;(3)不同色型棕背伯劳日平均活动时间区间和时间长度无显著差异(P>0.05).据此认为,棕背伯劳两种色型在家域行为上未表现出明显的分化.     

Seasonal migration by a large forest ungulate: a study on takin (Budorcas taxicolor) in Sichuan Province, China

Migration in large mammals is a biological phenomenon that involves seasonal movements over a vertical or horizontal scale that encompasses distances of more than several home ranges. Takin are large bovid herbivores that conduct seasonal migrations. From 2006 to 2009, we utilized data from 9 GPS-collared animals and 22 trail event recorders to describe takin migration pattern at the level of both individuals and population. We found seasonal migration of takin over an elevation gradient which contained two migration cycles, with takin inhabiting the highest elevations in summer, lowest elevations in spring and autumn, and intermediate elevations during winter. These movements did not involve expansion of home range size but rather shifts in distribution. Habitat availability analysis based on five forest types indicated that takin showed significant monthly forest preferences. Based on both telemetry and trail monitors, mature forest with bamboo understory was the habitat favored by takin for more than 8 months of the year. Both methods also indicated that not all individuals migrated to the highest elevations during summer or the lowest elevations in winter. We also found that individual takin do not necessarily follow the same annual movement, as three out of the four animals with at least 2 years of data changed their migration pattern between years. Current protocols for annual surveys conducted at high-elevation meadows or low-elevation valleys are not adequate to detect all individuals. We suggest that surveys must include all potential habitats and include detection functions in order to accurately estimate takin numbers or relative changes in their density.     

Distinct seasonal habitat selection by annually sedentary mountain hares (Lepus timidus) in the boreal forest of Sweden

Mountain hares (Lepus timidus) show high site fidelity even though they are non-territorial and sometimes make long excursions to new areas outside their home range. This study investigates how far apart consecutive annual and seasonal home ranges of the same individual are situated, how much they overlap and if habitat preference can explain the observed high site fidelity. The results show that hares usually overlap their previous home range, both between seasons and years, although the seasonal overlap is smaller, indicating that hares show a more pronounced change of areas between seasons than between years. The seasonal habitat selection was very distinct, tracking changing resource availability between seasons, while the annual selection was difficult to interpret as it mixed the seasonal patterns. Consequently, the annual selection seems to be merely an artefact from the more important seasonal selection. I therefore caution that results from habitat selection studies based on annual home ranges that are estimated from animals in seasonally differing environments should be treated with care. It appears that while seasonal home ranges are selected on the basis of resource availability, there is sufficient variation in the strength of this response to suggest that a mountain hares local knowledge of an area could also explain fidelity to their annual home ranges.     

Space use and site fidelity of wintering whooping cranes on the Texas Gulf Coast

The Aransas-Wood Buffalo population (the only non-reintroduced, migratory population) of endangered whooping cranes (Grus americana) overwinters along the Texas Gulf Coast, USA. Understanding whooping crane space use on the wintering grounds reveals essential aspects of this species' ecology, which subsequently assists with conservation. Using global positioning system telemetry data from marked whooping cranes during 2009–2017, we fit continuous-time stochastic process models to describe movement and home range using autocorrelated kernel density estimation (AKDE) and explored variation in home range size in relation to age, sex, reproductive status, and drought conditions. We used the Bhattacharyya coefficient of overlap and distance between home range centroids to quantify site fidelity. We examined the effects of time between winter home ranges and the sex of the crane on site fidelity using Bayesian mixed-effects beta regression. Winter whooping crane 95% AKDE home range size averaged 30.1 ± 45.2 (SD) km² (median = 14.3, range = 1.1–308.6). Home ranges of sub-adult females were approximately 2 times larger than those of sub-adult males or families. As drought worsened, home ranges typically expanded. Between consecutive years, the home ranges of an adult crane exhibited 68 ± 31% overlap (site fidelity), but fidelity to winter sites declined in subsequent winters. The overlap of adult home ranges with the nearest unrelated family averaged 33 ± 28%. As a whooping crane aged, overlap with its winter home range as a juvenile declined, regardless of sex. By 4 years of age, a whooping crane had approximately 14 ± 28% overlap with its juvenile winter home range. Limited evidence suggested male whooping cranes return to within 2 km of their juvenile home range by their fifth winter. Previous data obtained from aerial surveys led ecologists to assume that whooping crane families normally used small areas (~2 km²) and expressed persistent site fidelity. Our analyses showed <8% of families had home ranges ≤2 km², with the average area 15 times greater, and waning site fidelity over time. Our work represents an analysis of whooping crane home ranges for this population, identifying past misconceptions of winter space use and resulting in better estimates of space requirements for future conservation efforts.     

Staying close to home: Ecological constraints on space use and range fidelity in a mountain ungulate

Understanding patterns of animal space use and range fidelity has important implications for species and habitat conservation. For species that live in highly seasonal environments, such as mountain goats (Oreamnos americanus), spatial use patterns are expected to vary in relation to seasonal changes in environmental conditions and sex‐ or age‐specific selection pressures. To address hypotheses about sex, age, and seasonality influence on space‐use ecology, we collected GPS location data from 263 radio‐collared mountain goats (males, n = 140; females, n = 123) in coastal Alaska during 2005–2016. Location data were analyzed to derive seasonal and sex‐specific fixed‐kernel home range estimates and to quantify the degree of seasonal range and utilization distribution overlap. Overall, we determined that home range size was smallest during winter, expanded coincident with the onset of green‐up and parturition, and was largest during summer. Home range size of males and females did not differ significantly during winter, but females had larger home ranges than males during summer, a relationship that was switched during the mating season. Pairwise comparisons involving individual females across subsequent years indicated home ranges were significantly smaller during years when they gave birth to offspring. Mountain goats exhibited a strong degree of range fidelity, and 99% (n = 138) of individual animals returned to their previous year''s seasonal range with an average annual Bhattacharyya''s affinity utilization distribution overlap index of 68%. Similarity of seasonal home range utilization distributions varied in relation to sex and season in some respects. Home range overlap was highest during the summer vegetation growing season, particularly among females. These findings advance our understanding about how environmental variation and sex‐ and age‐related reproductive constraints influence space use and range fidelity among alpine ungulates. Documentation of the high degree of range fidelity among mountain goats has important conservation implications in landscapes increasingly altered by anthropogenic activities.     

Home ranges of raccoon dogs (<Emphasis Type="Italic">Nyctereutes procyonoides</Emphasis>, Gray, 1834) in Southern Brandenburg,Germany

The raccoon dog Nyctereutes procyonoides, a medium-sized canid, is a representative of the East Asian fauna and has been introduced to Europe during the years 1928–1953. Today, this alien carnivore is a widespread species in Eastern Europe, Finland and Germany. In our study, we determined home range sizes of raccoon dogs in an agricultural landscape in Northeast Germany between 2001 and 2004 by very high frequency radio tracking. Those data are useful for estimation of predator densities in respect to conservation of biodiversity and also to develop models for disease and parasite transmission. Yearly average home range sizes were calculated as 95% fixed kernel: 1.83 km² ± 1.54 and as 50% fixed kernel (=core areas): 0.50 km² ± 0.49. We documented seasonal differences in home range sizes as well as overlapping of home ranges from 0.65% up to 67%. Some individuals’ home ranges recorded during the same season showed a clear shifting between different years. Abandoned badger dens, located in the core areas of raccoon dogs home ranges, were important during the whole year and particularly used in the winter period. Therefore, distribution of those dens had some influence on the spatial distribution of raccoon dogs in the study area. Based on mean annual home range size, we estimated the mean local population density during winter as 1.1 individuals per square kilometre and during summer as 4.90 individuals per square kilometre.     

Home range and habitat selection of an insular fallow deer (<Emphasis Type="Italic">Dama dama</Emphasis> L.) population on Little St. Simons Island,Georgia, USA

A better understanding of habitat use and home range size for an exotic fallow deer (Dama dama L.) population in coastal Georgia is needed to understand the relationship between this introduced species and the barrier island ecosystem. These spatial requirements will aid in management decisions to limit negative impacts to the deer or sensitive habitats. We describe annual and seasonal home range and habitat use of seven fallow deer fitted with GPS collars. Home ranges of females averaged 130.3 ± 0.45 ha based on a 95% local convex hull (LoCoH) nonparametric kernel method. Home ranges of adult males were highly variable, ranging from 56.9 to 354.8 ha. We examined site fidelity by analyzing shifts in core areas and percent overlap across seasons. Only one individual exhibited a seasonal range shift; all other deer demonstrated a high level of site fidelity. Based on compositional analysis of habitat use versus availability, fallow deer avoided salt marshes but showed individual variation in selection of other habitats. Maritime shrub was the most commonly preferred habitat type on the barrier island. Fallow deer have adapted to effectively use available habitats on the barrier island and have successfully excluded native white-tailed deer from recolonizing LSSI.     

Habitat Selection and Home Range Dynamics of Eastern Spotted Skunks in the Ouachita Mountains,Arkansas, USA

ABSTRACT Since the 1940s, eastern spotted skunks (Spilogale putorius) have declined dramatically throughout the Midwest. One hypothesis for the decline is the loss of suitable habitat, although little is known about the ecological requirements of this species. To elucidate seasonal home range and habitat selection by eastern spotted skunks, we conducted telemetry-based field work in the Ouachita Mountains of western Arkansas, USA. During 2 years of field work, we collected day- and nighttime radiolocations for 33 eastern spotted skunks. We used kernel-based utilization distributions, volume of intersection indices, and weighted compositional analysis to evaluate seasonal home range dynamics and habitat selection. Although we found moderate adult male site fidelity, there were large seasonal differences in home range size, with ranges of between 76 ha and 175 ha (± 22–62 SE) during summer, fall, and winter, and home ranges of 866 ha (± 235 SE) during spring. Male home range increases in the spring were likely caused by questing behavior in search of reproductive females. Females maintained home ranges of 54 ha to 135 ha (± 7–30 SE) and moderate site fidelity during all seasons. During each season, we observed selection of young shortleaf pine (Pinus echinata) and hardwood stands over other available cover types, likely due to a preference for a dense, complex understory and a closed canopy overstory to reduce predation risk. Most habitats in the study region were managed for an herbaceous understory and an older, more open canopy, in part to benefit red-cockaded woodpecker (Picoides borealis) populations. Thus, if simultaneous management for these 2 vertebrates is a goal, a balance of early and late successional habitat should be reached.     

Spatial organisation and dynamics of the pine marten Martes martes population in Białowieza Forest (E Poland) compared with other European woodlands

We studied factors affecting density and spacing patterns in the pine marten Martes martes population inhabiting temperate forests of Bia?owieza National Park, eastern Poland. From 1985/1986 to 1995/1996 marten densities ranged from 3.63 to 7.57 individuals 10 km^?2 (mean 5.4) and were positively correlated with abundance of forest rodents in the previous year. The rate of marten population growth was inversely density‐dependent and positively related to rodent density. Annual mortality rate averaged 0.384 and tended to be negatively related to marten densities. Mean annual home range of males (2.58 km², SE=0.24) was larger than that of females (1.41 km², SE=0.20). Seasonal home ranges also differed significantly between males and females. Both sexes held the smallest ranges in December–January. Female ranges increased in April–May, whereas those of males increased in June–September when they were mating. Fidelity of pine martens to their home ranges was very high. The mean shift between arithmetic centres of seasonal ranges was 0.25 km, and the ranges recorded in two consecutive seasons overlapped, on average, by 87–90%. We observed very little home range overlap between neighbouring male (mean 4–6%) or female (mean 6%) marten. Year round the neighbouring individuals of the same sex neither avoided nor attracted each other. Females attracted males only during the spring‐summer mating season. A review of other studies has documented that winter severity and seasonal variation in ecosystem productivity were essential factors shaping the biogeographic variation in pine marten densities between 41^o and 68^oN. The density of marten populations increased in areas with mild winters and lower seasonality. Maximum population densities (indicative of habitat carrying capacity) were correlated with mean winter temperature. In Europe, male home ranges increased with decreasing forest cover in a study area, whereas female ranges varied positively with rodent abundance.     

Spatial ecology and habitat use of giraffe (Giraffa camelopardalis) in South Africa

The lack of long-term studies remains a limiting factor in understanding the home range, spatial ecology and movement of giraffes. We equipped eight giraffes with GPS satellite units and VHF capacity, which were built in to the collars for the remote collection of data on their movements and home ranges over two years on Khamab Kalahari Nature Reserve (KKNR) within the Kalahari region of South Africa. Giraffe numbers in KKNR dropped from 135 individuals to 111 in just five years, revealing the lack of knowledge about their required habitat needs, space use and diet. With over 1000 km² available for roaming within the reserve, habitat selection, principle and preferred food species played a significant role in home range size and overlap between individuals. These giraffes used an average annual home range of 206 km² (20 602 ha) as calculated by a 95% minimum convex polygon (MCP) with a standard deviation core home range calculated by a 50% MCP of 10.1 km² to satisfy their annual needs for survival and reproduction in their preferred vegetation. In the wet, hot season (summer: December–February) when food was abundant, giraffes frequented smaller areas (average 177 km²), while in the dry, cool season (winter: June to August) the mean home range size increased to approximately 245 km². Rainfall influenced spatial distribution since it determined vegetation productivity and leaf phenology. The different seasons influenced giraffe movements, while different vegetation types and season influenced their home range size. Season and food availability also influenced home range overlap between different giraffe herds. Home range overlap occurred when giraffes were forced to roam in overlapping areas during the dryer months when the winter deciduous nature of the majority of the tree species resulted in lower food availability. In winter, the overlap was approximately 31% and in autumn approximately 23%. During the wet and warmer months, overlapping was 15% in summer and 19% in spring, respectively. The percentage of time spent in different vegetation type areas was influenced by the abundance of the principal food species of that plant community. It is thus concluded that the movements of giraffes were primarily influenced by a combination of environmental factors such as season, rainfall and vegetation density.     

Population Structure and Ranging Patterns of <Emphasis Type="Italic">Rhinopithecus roxellana</Emphasis> in Zhouzhi National Nature Reserve,Shaanxi, China

We describe the population structure and ranging patterns of a troop of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) based on a study conducted between November 2002 and November 2003 in Zhouzhi National Nature Reserve, Shaanxi Province, China. The troop comprised several 1-male units and an all-male unit. Opportunistic censuses revealed that there were ≥112 individuals in the troop. The adult sex ratio (male vs. female) was 1:3.7. The ratios of adults to immatures and infants to adult females were 1:0.7 and 1:2, respectively. Via a grid system, we estimated the home range of the troop to be 18.3 km², of which 7.4 km² was the core area. The subjects exhibited distinct seasonal ranging patterns. Their movement across the home range was extensive in spring and restricted in autumn. In addition, reuse of quadrats was highest in winter and lowest in spring in comparison with other seasons. The daily path length (DPL) varied from .75 to 5 km, with a mean of 2.1 km. Seasonal analysis showed that DPL is significantly shorter in winter than in spring or summer; however, there is no significant difference between the DPLs of spring and summer or those of spring and autumn. The monkeys occupied elevations 1500–2600 m above sea level; the annual mean of altitudinal range is 2137 m. Contrary to early studies that reported Rhinopithecus roxellana migrates to lower elevations in winter, we found no evidence supporting a seasonal altitudinal shift. Using the highest troop count and home range estimate, and considering the extent of range overlap between neighboring troops, we calculated the population density and biomass of Rhinopithecus roxellana to be 7.2 individuals/km² and 68.3 kg/km², respectively. The temporal and spatial distribution of food resources may be the most important determinant of ranging behavior in Rhinopithecus roxellana, though understanding the relationship between resource distribution and seasonal range use may require further investigation.