达乌尔鼠兔扩散过程中的生境选择

通过调控牧压,研究了达乌尔鼠兔扩散过程中的生境选择。结果表明,放牧活动强了草原植被的斑块性,改变了植被为鼠兔提供的资源条件,导致鼠兔斑块间的扩散和扩散鼠兔对不同植被斑块的生境选择。     

江苏盐城滨海湿地外来种互花米草的时空动态及景观格局

基于1992—2007年的遥感影像和野外调查数据,在地理信息系统的支持下,应用景观生态学理论和转移矩阵方法,定量分析了江苏盐城滨海湿地外来种互花米草的时空动态及其景观格局的演变规律.结果表明：研究区互花米草面积由1992年的3561 hm²上升至2007年的14491 hm²,增幅达306.94%,累计转入和转出面积分别为26291和15361 hm²;其中,江苏盐城国家级自然保护区核心区的互花米草面积由1992年的597 hm²增长到2007年的2814 hm ²,年增幅达24.74%.研究期间,该区互花米草空间分布格局由初始的河口地带零星斑块逐渐演变为连续带状,并扩展到射阳河口至梁跺河口之间的滩涂外围;研究区互花米草的斑块重心向东南方向移动（2.92 km）,平均斑块面积先增（1992—2002年）后降（2002—2007年）,最大斑块指数及面积加权临近度指数逐年递增,斑块形状趋向规则化.     

内蒙古典型草原4种常见小哺乳动物的营养生态位及相互关系

本文根据布氏田鼠、达乌达鼠兔、达乌尔黄鼠和草兔在自由生活下的食物组成,分别计算了它们之间的实际营养生态位重叠程度及生态位宽度。还计算了布氏田鼠、达乌尔鼠兔和达乌尔黄鼠间的原始营养生态位重叠程度及宽度。由于栖息地资源可利用性的限制,这３种小哺乳动物的实际营养生态位较原始营养生态位穿。分布空间的重叠可导致布氏田鼠与达乌尔鼠兔间实际营养生态位的较高程度重叠。此结果支持了ＭａｃＡｒｔｈｕｒ和Ｗｉｌｓｏｎ（     

高原鼠兔与达乌尔鼠兔食物资源维生态位的研究

作者于１９９３年在青海省刚察县年诺索玛地区发现高原鼠兔（Ｏｃｈｏｔｏｎａ ｃｕｒｚｏｎｉａｅ）和达乌尔鼠兔（０．ｄａｕｒｉｃａ）在布哈河谷二阶同域且重叠分布之现象,并从这两种鼠兔的食物资源利用出发,研究了其生态位关系问题。在食物资源维上的生态位宽度（ＰＳ）,高原鼠兔为０．４７４４,达乌尔鼠兔为０．４９６４,即它们具有相近似的生态位宽度。这两种动物的生态位在食物资源谱维上的重叠值（ＦＴ）为０．８０９     

高原鼠兔家群空间领域的季节性动态格局

为探讨高原鼠兔家群空间领域的季节特征,分别于2005年和2006年的5～8月,在青海省玛沁县,采用标志重捕法和最小多边形面积法对其家群巢区和核域进行了研究.结果表明,不同季节,高原鼠兔巢区和核域面积存在显著差异.5、6月份,成体巢区面积显著大于幼体,但二者核域面积却无显著差异;7月份,成体与第1胎幼体巢区及核域面积均显著大于第2胎.5、6月份雄性成体巢区显著大于7、8月份,6、7月份雌性成体巢区显著大于5月和8月份.巢区及核域面积均与家群个体数呈极显著性正相关关系,说明季节和家群结构均可对高原鼠兔空间领域产生重要作用.     

香鼬的活动节律和巢区

本文采用无线电遥测技术对栖息在自然环境中香鼬（Ｍｕｓｔｅａｌａｌｔａｉｃａ）的活动节律及其巢区进行了较为系统的研究。结果表明,香鼬多营独居生活．除繁殖期外,无论雌雄个体均无长期稳定的巢穴,经常更换活动的位置。香鼬的每日活动主要为玩耍、自身的修饰、光浴、探视和取食,在繁殖期还有育幼及对幼鼬的保护。在不同时期香鼬日活动高峰和巢区大小均有不同。幼鼬出洞活动前,其亲体雌性成鼬活动呈现两个明显的高峰,１１：００～１３：００和１６：００～１７：００,雄性成鼬则只有一个活动高峰在１１：００左右;在这一时期,成体香鼬的地面活动高峰与其食物──高原鼠兔的地面活动高峰不相吻合,雌性成鼬的巢区面积为７．２１ｈａ,雄性成鼬的巢区面积为１１．７ｈａ。幼鼬出洞活动后,雌性成鼬的活动高峰为８：００～９：００和１７：００～１９：００,巢区面积平均为８２．７２ｈａ。幼鼬扩散期间;雌性成鼬的活动高峰期分别为８：００～９：００和１５：００～２０：００。在这两个时期。成体香鼬的地面活动高峰与高原鼠兔的地面活动高峰趋于一致。影响香鼬活动和巢区大小的主要因素是食物的丰富度、猎物的活动性和繁殖行为,同时种群密度也是主要因素之一。     

保加利亚北部地区匈牙利小家鼠的空间组织结构

本文研究了保加利亚北部地区的匈牙利小家鼠在繁殖期的空间关系和分布。这种动物最普遍的空间关系是一雄一雌,也观察到两个或三个雄鼠与一个雌鼠、一个雄鼠与两个或三个雌鼠的组织形式。很少观察到雌性的社群小组。雌鼠之间的巢区没有发现重叠。一般雄鼠的巢区大于雌鼠。有一半雄鼠的巢区与一个雌鼠的巢区相重叠,其他的雄鼠与两个成年雌鼠的巢区相重叠。这些结果表明,匈牙利小家鼠具有多变的社群繁殖婚配体制,即单配制和多配制共存。比较普遍的一雄一雌的配对形式和雌性的独居特性,以及雌性之间巢区的相对独立性,表明单配制是该物种的主要婚配体制。     

高原鼠兔与达乌尔鼠兔的摄食行为及对栖息地适应性的研究

通过对标志高原鼠兔和达乌尔鼠兔直接观察的方法,对它们的摄食行为及栖息地适应性进行了研究。两种鼠兔的摄食行为链存在着明显趋同的行为程序时间系列。在摄食活动中,前者用于防御敌害的时间分配较多。而达乌尔鼠兔则花费更多的时间于采食。对小生境内的高大植株进行刈割,是高原鼠兔保持其防御视野开阔,降低被捕食风险的适应性策略;达乌尔鼠兔则善于利用栖息地内高大植株覆盖物作为它们的临时隐蔽所,以有效地躲避敌害。这表明它们具有反捕食的行为调控能力,也证明捕食风险强化了物种对栖息地的选择。     

黑线仓鼠巢区的研究

1987年6—9月用标志重捕流放法在呼和浩特地区对黑线仓鼠的巢区进行了研究,雌、雄性的巢区分别为2720.6±576.0平方米和7684.1±1736.6平方米,活动距离分别为95.5±14.4米和135.9±12.4米。黑线仓鼠巢区和活动距离季节变化不明显,雄鼠巢区6—9月全部重叠,雌鼠巢区只有9月份不重叠,雌、雄性巢区彼此重叠。     

高原鼠兔和高原鼢鼠种群暴发区干扰斑块空间分布格局与演替规律

高原鼠兔(Ochotona curzoniae)和高原鼢鼠(Myospalax baileyi)是两种在高寒草甸广泛分布的小型哺乳动物,其暴发活动可能造成高寒草甸的严重退化。使用无人机分别拍摄典型的高原鼠兔和高原鼢鼠种群暴发区图像,解译高原鼠兔洞口、高原鼢鼠土丘和它们的干扰斑块,获得干扰斑块的周长和面积信息,计算干扰斑块形状指标,确定高原鼠兔与高原鼢鼠暴发活动对高寒草甸的影响。研究表明：(1)高原鼠兔与高原鼢鼠暴发活动形成的干扰斑块周长与面积比(PARA)、形状指数(SHAPE)和分形维数(FRAC)差异显著(P<0.05),其中高原鼢鼠斑块的FRAC是1.0124±0.0091,属于普通的规则几何圆形分布格局,高原鼠兔斑块的FRAC是1.1203±0.0546,属于分形几何不规则的分布格局。(2)高原鼠兔洞口数量与其斑块面积没有线性相关关系(P=0.9677),高原鼢鼠土丘数量与其斑块面积呈显著正相关(P<0.05)。(3)高原鼢鼠斑块面积统计学上呈长尾分布,不符合正态分布(P<0.01)。根据高原鼠兔斑块面积分布格局可将斑块演替分为三个阶段：土丘形成阶段、斑块连通...     

Insights into post-fledging dispersal of Bearded Vultures Gypaetus barbatus in southern Africa from GPS satellite telemetry

Capsule: Fledglings progressively increase their home range size and ranging behaviour as they age.

Aims: To examine the home range size and ranging behaviour of Bearded Vulture fledglings during the post-fledging dependence period and determine the onset of natal dispersal.

Methods: Post-fledging movements of three individuals were investigated in southern Africa using global positioning system (GPS) satellite telemetry which enabled home range sizes and distances travelled from the nest to be calculated.

Results: Fledglings increased their home range size from an average of 0.4–10 999?km² (100% Minimum Convex Polygons) and 9.13–11 466?km² (fixed 95% kernels) within the first six months post fledging. They also increased home range use as they aged with maximum daily distances travelled from the nest occurring between 98 and 136 days post fledging (when fledglings were aged between 222 and 262 days), after which time they dispersed from their natal area. Distances between fixes were highest during the dispersal period.

Conclusion: GPS satellite telemetry allows us to accurately demonstrate how fledglings progressively increase and use their home ranges as they age and undertake pre-dispersive exploratory flights. Results confirm the notion that juveniles disperse at the onset of the following breeding season and suggest that dispersal occurs earlier in the southern hemisphere.     

Home range and habitat use by the serotine bat, Eptesicus serotinus, in England

Serotine nursery roosts with less than 20 bats were found to have home ranges of at least 24 to 77 km² and core areas of activity from 13 to 33 km². The size of the range may have increased further if more individuals had been tracked, as three of the four colonies studied had not reached their asymptotes. The total home-range area covered by four serotine colonies was 127.36 km². Excluding non-breeding bats, a density of one bat per 120 ha was estimated. However, actual density was likely to be higher if there were additional non-breeding females and immatures that were not in nursery roosts. Colonial home ranges and core areas overlapped, with individuals from different colonies feeding at the same sites. Individual home ranges ( n = 32) varied from 0.16 to 47.58 km², but these were not used exclusively by one individual. Around the colonial core area and breeding roosts, home ranges were used by all individuals from a single colony. It is only further from the core area that ranges appeared to be used by individuals. The distance from roost to feeding areas varied by up to 7.4 km, but the bat usually commuted along lines of trees and hedges and over pastures. This resulted in greater distances being travelled than if they had flown by a direct route. On average, individuals commuted distances of 8 km each night between feeding areas, with a maximum distance of over 41 km. They visited between 0 and 10 feeding sites each night (mean = 2.89).     

Post-juvenile dispersal of Hazel Grouse Bonasa bonasia in an expanding population of the southeastern French Alps

We studied the post-juvenile dispersal of 18 radiotagged juvenile Hazel Grouse Bonasa bonasia (14 males, four females) in an expanding population in the southeastern French Alps between 1998 and 2001. The mean dispersal distances between the capture sites of juveniles in September–October and the centre of the home range in the following spring was 4 km for males (range 0.1–24.9 km) and 2 km for females (range 0.2–5.6 km). The distances recorded for two long-dispersing males (15 and 24.9 km) are greater than those reported to date for Hazel Grouse. Using our radiotracking data, we interpret the pattern of range expansion that has been occurring since the 1950s around our study area. Barriers to dispersal included rocky ground and other alpine habitats above 2000 m and over 1 km wide, but Hazel Grouse did cross open agricultural land at lower elevation. Two patterns of dispersal movements were recognized in juveniles: erratic movements that led to settlement on or near the natal site, and direct movements to a new range relatively far from the natal area. We discuss the adaptive consequences of these different behaviour patterns.     

DIRECT AND INDIRECT ESTIMATES OF NEIGHBORHOOD AND EFFECTIVE POPULATION SIZE IN A TROPICAL PALM,ASTROCARYUM MEXICANUM

To estimate the relative importance of genetic drift, the effective population size ???(N_e) can be used. Here we present estimates of the effective population size and related measures in Astrocaryum mexicanum, a tropical palm from Los Tuxtlas rain forest, Veracruz, Mexico. Seed and pollen dispersal were measured. Seeds are primarily dispersed by gravity and secondarily dispersed by small mammals. Mean primary and secondary dispersal distances for seeds were found to be small (0.78 m and 2.35 m, respectively). A. mexicanum is beetle pollinated and pollen movements were measured by different methods: a) using fluorescent dyes, b) as the minimum distance between active female and male inflorescences, and c) using rare allozyme alleles as genetic markers. All three estimates of pollen dispersal were similar, with a mean of approximately 20 m. Using the seed and pollen dispersal data, the genetic neighborhood area (A) was estimated to be 2,551 m². To obtain the effective population size, three different overlapping generation methods were used to estimate an effective density with demographic data from six permanent plots. The effective density ranged from 0.040 to 0.351 individuals per m². The product of effective density and neighborhood area yields a direct estimate of the neighborhood effective population size (N_b). N_b ranged from 102 to 895 individuals. Indirect estimates of population size and migration rate (Nm) were obtained using F_st for five different allozymic loci for both adults and seeds. We obtained a range of Nm from 1.2 to 19.7 in adults and a range of Nm from 4.0 to 82.6 for seeds. We discuss possible causes of the smaller indirect estimates of Nm relative to the direct and compare our estimates with values from other plant populations. Gene dispersal distances, neighborhood size, and effective population size in A. mexicanum are relatively high, suggesting that natural selection, rather than genetic drift, may play a dominant role in patterning the genetic variation in this tropical palm.     

杭州石荠苧的传粉、小坚果散布和邻群大小

作者在杭州葛岭对杭州石荠苧自然居群的传粉和小坚果散布进行了详细的观察和实验。结果显示 ,以 2 6 0个传粉昆虫的飞行距离推算的花粉绝对散布方差为 0 .0 82 m2 ,798个小坚果的亲子散布方差为0 .1587m2。在上述散布特点和异交率为 0 .92 5条件下的邻群面积为 2 .2 33m 2 ,在有效密度为 4 7.7株 / m 2的有效密度下的邻群大小为 10 6 .5株。杭州石荠以异交为主 ,非常有限的基因散布导致邻群面积很小 ,居群容易发生遗传分化。     

Seasonal movement, dispersal, and home range of Northern Snakehead Channa argus (Actinopterygii, Perciformes) in the Potomac River catchment

Knowledge of the movement behaviour and dispersal ability of non-native species can aid in their management by informing risk assessments and the development of control strategies. To improve understanding of the seasonal movement and dispersal behaviour of Northern Snakehead (Channa argus), we implanted 49 fish in the Potomac River with radio tags and tracked movements from October 2006 to 2007. In addition, we tested the hypotheses that activity level, dispersal ability, and home range size varied with fish size. Home range was calculated for 24 fish. Of these, 19 exhibited stable home ranges averaging 1.2 km² in size. Thirteen fish (31% of survivors) dispersed an average distance of 18 km between 30 April and 7 June, mostly upstream (92%) and across the main river channel. Fish moved greater distances during the pre-spawn season compared to the spawning season. There was no relationship between fish length and any behavioural measure. Upstream dispersal was restricted by barriers such as dams; therefore, Northern Snakehead can likely disperse greater distances than observed here. Our observations demonstrate the invasiveness of Northern Snakehead by showing that a large portion of adults dispersed over considerable distances, suggesting spread may be rapid in large, open freshwater systems.     

Evolutionarily stable consumer home range size in relation to resource demography and consumer spatial organization

There is a large variation in home range size within species, yet few models relate that variation to demographic and life-history traits. We derive an approximate deterministic population dynamics model keeping track of spatial structure, via spatial moment equations, from an individual-based spatial consumer-resource model; where space-use of consumers resembles that of central place foragers. Using invasion analyses, we investigate how the evolutionarily stable home range size of the consumer depends on a number of ecological and behavioral traits of both the resource and the consumer. We show that any trait variation leading to a decreased overall resource production or an increased spatial segregation between consumer and resource acts to increase consumer home range size. In this way, we extend theoretical predictions on optimal territory size to a larger range of ecological scenarios where home ranges overlap and population dynamics feedbacks are possible. Consideration of spatial traits such as dispersal distances also generates new results: (1) consumer home range size decreases with increased resource dispersal distance, and (2) when consumer agonistic behavior is weak, more philopatric consumers have larger home ranges. Finally, our results emphasize the role of the spatial correlation between consumer and resource distributions in determining home range size, and suggest resource dispersion is less important.     

Home Range and Movement Patterns of Toucans: Implications for Seed Dispersal

Toucans (Ramphastidae) are highly frugivorous, widespread throughout the Neotropics, and travel long distances, thus likely providing dispersal for many tropical trees. Despite being large conspicuous members of the canopy and subcanopy bird community, their movement ecology has been little studied. To understand how these frugivores move through a lowland tropical forest, I tracked the movements of Ramphastos tucanus (White‐throated Toucan), Ramphastos vitellinus (Channel‐billed Toucan), and Pteroglossus pluricinctus (Many‐banded Araçari) in Yasuní National Park, Ecuador. The objectives of this study were to use radiotelemetry to estimate toucan home ranges, movement patterns, and potential seed dispersal distances. Using canopy nets, a total of 20 P. pluricinctus and three Ramphastos toucans were captured, radio‐tagged, and tracked over a 4‐yr period from 2001 to 2005. Average home range sizes were 191 and 86 ha for P. pluricinctus and Ramphastos toucans, respectively. The maximum travel distance in a single 30‐min tracking interval was 3665 m for P. pluricinctus and 3027 m for Ramphastos. Estimated dispersal distances of medium‐sized seeds ranged from 269 to 449 m. Large home range size and long‐distance movements indicate that toucans likely disperse seeds over a scale of hundreds of meters. This study is the first to estimate home range size of any toucan species in intact closed‐canopy forests. Abstract in Spanish is available at http://www.blackwell‐synergy.com/loi/btp .     

Home range of the raccoon dog (Nyctereutes procyonoides) in southern Finland

Home ranges, relationships between individuals and dispersal among raccoon dogs ( Nyctereutes procyonoides ) were studied in southern Finland in 1989-91. The average maximum home range, calculated by the harmonic mean method. was 9·5 km² and the core area (85% utilization) 3·4 km². There were no statistically significant annual. seasonal or sexual differences in the size of the average core area of adults, but the home ranges of juveniles in autumn were larger than those of adults. However. the maximum home ranges of adults were larger in autumn than in summer, especially those of males, which were conspicuously small in summer and large in autumn. The core areas of adjacent pairs did not usually overlap in the pup-rearing season. but in autumn some home ranges shifted and there was much more overlap. The home ranges of the male and female of a pair overlapped almost totally, and a male and a female sharing the same home range also travelled together or close to each other, thus supporting the idea that the raccoon dog is monogamous in Finland. None of the adults left the study area, but 38% of the juveniles were recovered further than 10 km from the marking place during the first autumn.     

A telemetry-based study of bushbuck (Tragelaphus scriptus) home range in Valley Bushveld

With the aid of radio‐telemetry, bushbuck home range was investigated to determine total home range size, home range utilization and home range overlap for the summer season. Estimates of total home range size for males using minimum convex polygons (MCPs) and fixed kernels (FKs) were 33.9 and 32.1 ha, respectively. Estimates of total home range size for females using MCPs and FKs were 12.0 and 13.5 ha, respectively. A significant difference between total home range sizes for male and female was found but there was no significant difference for age (adult and subadult). Female bushbuck home range size was compared to that expected from the published allometric relationship for the scaling of home range area on body mass, where the study animals appeared to have home ranges of half of that predicted. Bushbuck typically utilized one core area within their home ranges in which 50% of their time was spent in approximately 17.0% and 11.7% of their total home range for males and females, respectively. A substantial overlap in total home range and core areas between animals was found.