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1.
Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual''s age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km2. Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km2) of the overall range. Average adult home ranges (286 km2) were only around 1% the size of the average foraging ranges of non-adults (10 540 –25 985 km2), with those of breeding adults being even smaller (95 km2). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species'' range to be targeted for management planning, education and conservation action.  相似文献   

2.
The distribution of food resources in time and space may affect the diet, ranging pattern, and social organization of primates. We studied variation in ranging patterns in a group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) over winter and summer in response to variation in their diet in the Qingmuchuan Nature Reserve, China. There was a clear diet shift from highly folivorous in winter to highly frugivorous in summer. The home range was 8.09 km2 in summer and 7.43 km2 in winter, calculated via the 95% kernel method. Corresponding to the diet shift, the focal group traveled significantly longer distances in summer (mean 1020 ± 69 m/d) than in winter (mean 676 ± 53 m/d); the daily range was also significantly greater in summer (mean 0.27 ± 0.02 km2/d) than in winter (mean 0.21 ± 0.01 km2/d). There was no significant variation in home range size between winter and summer, and the monkeys did not use geographically distinct ranges in summer and winter. However, overlap in the actual activity area and core range between winter and summer was only 0.13 km2, representing 4.4% of the summer core area and 5.3% of the winter core area. Differences were apparent between summer and winter ranging patterns: In summer, the group traveled repeatedly and uninterruptedly across its home range and made 3 circles of movement along a fixed route in 31 d; in winter, the activity area was composed of 3 disconnected patches, and the focal group stayed in each patch for an average of 8 successive days without traveling among patches. Winter range use was concentrated on mixed evergreen and deciduous forest patches where leaves and fruits were available, whereas the summer range pattern correlates significantly positively with the distribution of giant dogwood (Cornus controversa) fruits. Thus it appears that the diet shift of Sichuan snub-nosed monkeys between winter and summer caused the monkeys to use their home range in different ways, supporting the hypothesis that food resources determine primate ranging patterns.  相似文献   

3.
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)。  相似文献   

4.
Abstract: Fishers (Martes pennanti) were almost extirpated in Ontario, Canada, south of the French and Mattawa rivers by the 1940s but have recolonized much of their former range over the past several decades. We assessed the effect of the current harvest quota on a fisher population in eastern Ontario by estimating home range size and population density from a sample of radiocollared animals. Mean (± SD) adult home ranges (based on annual 95% min. convex polygons) were consistently smaller than those reported in the literature (M: 11 ± 4.4 km2; F: 2.1 ± 0.8 km2), with up to 71% overlap of adjacent intrasexual home ranges. This yielded an estimated adult fisher population density of 32.7/100 km2 of suitable habitat, as defined by the habitat composition within observed home ranges. We further estimated that between 2003 and 2005, trappers harvested 17.8-42.3% of the pretrapping population. These results suggest that although current fisher population density is high in our study area compared to reported densities in other areas, harvest rate is also high and an increase in quota is unwarranted.  相似文献   

5.
四川羚牛的家域与忠诚度   总被引:1,自引:0,他引:1  
野生动物倾向回到或留在一个特定范围或者与原有区域完全重叠的行为被称为栖息地忠诚。利用GPS无线电颈圈对5只四川羚牛的家域及家域的季节和年度忠诚度进行了研究和分析(2006—2009年)。结果显示:四川羚牛年均家域面积为(MCP/FKE)(15.01±2.92)km2/(9.02±1.85)km2,但个体间及年际波动较大;季节间家域面积差异显著,个体家域的季节变化体现出较一致的变化模式,最大季节家域主要集中于春季和夏季。年际间季节家域忠诚度最高的是秋季和夏季,冬季家域年际忠诚度最低,春季家域忠诚度也相对较低。单因素方差分析显示季节间质心距离总体差异不显著,与家域重叠算法获得的忠诚度结论基本一致。  相似文献   

6.
Daily ranges of 19 (6 males, 13 females) adult red deerCervus elaphus Linnaeus, 1758 were studied using 24-h tracking sessions in Białowieża Primeval Forest (BPF), Poland, from 2001 to 2004. Overall, size of mean (± SE) daily ranges was larger for males (1.22 ± 0.10 km2) than females (1.00 ± 0.09 km2), although the difference was not significant. Similarly, mean daily ranges were 6–46% larger for males than females in each season, although there were no statistical differences in mean daily ranges among seasons for each sex. Abiotic factors, especially temperature, significantly affected daily ranges of females, but not males, suggesting sexual differences in response to weather variables. On a daily basis, males used 3% of their annual home range, whereas females used 12% of their annual home range, indicating females used their annual home ranges more intensely than males. Consecutive daily ranges overlapped little for each sex. Daily ranges of red deer in BPF were considerably larger than previously reported in Europe, suggesting factors unique to BPF also influenced size of daily ranges.  相似文献   

7.
Identifying climatic drivers of an animal population's vital rates and locating where they operate steers conservation efforts to optimize species recovery. The population growth of endangered whooping cranes (Grus americana) hinges on juvenile recruitment. Therefore, we identify climatic drivers (solar activity [sunspots] and weather) of whooping crane recruitment throughout the species’ life cycle (breeding, migration, wintering). Our method uses a repeated cross‐validated absolute shrinkage and selection operator approach to identify drivers of recruitment. We model effects of climate change on those drivers to predict whooping crane population growth given alternative scenarios of climate change and solar activity. Years with fewer sunspots indicated greater recruitment. Increased precipitation during autumn migration signified less recruitment. On the breeding grounds, fewer days below freezing during winter and more precipitation during breeding suggested less recruitment. We predicted whooping crane recruitment and population growth may fall below long‐term averages during all solar cycles when atmospheric CO2 concentration increases, as expected, to 500 ppm by 2050. Species recovery during a typical solar cycle with 500 ppm may require eight times longer than conditions without climate change and the chance of population decline increases to 31%. Although this whooping crane population is growing and may appear secure, long‐term threats imposed by climate change and increased solar activity may jeopardize its persistence. Weather on the breeding grounds likely affects recruitment through hydrological processes and predation risk, whereas precipitation during autumn migration may influence juvenile mortality. Mitigating threats or abating climate change should occur within ≈30 years or this wild population of whooping cranes may begin declining.  相似文献   

8.
Between December 1974 and November 1975 (157 days), it was found that seasonal home range changes in the Shiga C troop were closely related to food changes, vegetation, and the existence of neighbouring troops. The detailed points clarified may be summarized as follows: (1) The seasonal home range sizes from winter to autumn were 1.23 km2, 1.46 km2, 1.69 km2, and 1.21 km2, respectively, and the annual size was 3.66 km2; (2) The food changed from bark and buds of trees in winter to young leaves and stems of grasses and trees in spring and summer, and fruits in autumn; (3) Each home range clearly changed according to the phenology of the plants used as food at each season; (4) The food abundance for the monkeys was extremely poor in winter, relatively poor in summer, plentiful in spring, and the best in autumn; and (5) The Shiga C troop and the neighbouring Shiga B2 troop overlap in their home ranges in spring and autumn, but are separated during winter and summer.  相似文献   

9.
Abstract: We captured and radiocollared 57 pronghorn (Antilocapra americana) fawns in western South Dakota, USA, during May 2002–2003 and radiotracked them through 15 months of age, by which time all surviving individuals had established a permanent home range. We classified 56% (n = 19) of fawns as dispersers and 44% (n = 15) as residents. Eighty-four percent (n = 16) of dispersers departed natal home ranges in late October and occupied winter home ranges for 102–209 days before dispersing to permanent home ranges during April 2003 and 2004. Dispersal distances from natal ranges to permanent home ranges varied from 6.2–267.0 km. Winter home-range sizes for all individual pronghorns varied from 39.4–509.6 km. Permanent home-range size for all individuals varied from 15.5–166.1 km2. Mean 95% permanent home-range size differed (P = 0.06) between residents (x̄ = 97.3 ± 15.1 km2) and dispersers (x̄ = 48.6 ± 16.0 km2), but was similar (P = 0.97) among sexes. Mean dispersal distance from natal to permanent home ranges was similar (P = 0.35) for males (x̄ = 54.2 ± 21.0 km) and females (x̄ = 26.3 ± 19.9 km). We suggest that habitat quality (i.e., patchiness) and pronghorn density, in part, stimulated dispersal. We hypothesize that as habitat patch size decreases, home range sizes and distance traveled during predispersal and dispersal movements by pronghorns will increase.  相似文献   

10.
The seasonal home range size and spatial relationships of 16 adult genetsGenetta genetta Linnaeus, 1758 (6 males and 10 females) were estimated in a Mediterranean habitat of northeastern Spain. Genets minimum density was estimated as 0.98/km2. Mean annual home range was 113.1 ha in males and of 72.0 ha in females. Males had larger home ranges than females in all seasons, but differences were only significant in winter. Home range size changed seasonally and showed a similar pattern in both sexes, with lower values in summer (males — 41.2 ha, females — 29.0 ha) and maximum ones in spring (males — 78.8 ha, females — 56.1 ha). Animals displayed spatial fidelity throughout the year. Core areas (MCP50) represented 27% and 19% of total home range size for males and females, respectively. Resting home ranges (based on locations of inactive animals) were 9 times lower than overall home range size. Individuals of the same sex overlapped less than individuals of different sexes, especially with regard to core areas, which showed almost no overlap. The results obtained suggest that (1) different factors are likely to affect the space use of genets, such as body mass, food abundance and reproductive cycle; (2) genets use space in a heterogeneous way, with areas of greater activity than others within their home range; (3) there was intrasexual segregation with regard to space use.  相似文献   

11.
In addition to environmental factors, social variables such as group size may play an important role in explaining primate ranging patterns. In this study we investigated range sizes, site fidelity, and range overlaps of owl monkeys (Aotus azarae) in Northern Argentina. We calculated the size of home range and core areas for 18 groups in our study area. For the six most intensively studied groups we tested whether precipitation as a crude proxy for food availability or group size had an influence on range size, assessed the degree of site fidelity by quantifying overlaps of annual ranges and core areas, and calculated the amount of range overlap between neighboring groups for each year. We used the kernel density estimation method to calculate home ranges as 90% kernel and core areas as 50% kernel. Home range size (mean ± SD) was 6.2 ha (± 1.8) and core area size 1.9 (± 0.6). Rainfall and group size were not statistically significant predictors of range sizes. Site fidelity was high, with a range overlap of 82% (± 11) between consecutive years. Neighboring groups overlapped over 48% (± 15) of the outer parts of their group ranges and 11% (± 15) of their core areas. We found no evidence that larger groups occupy larger areas than smaller groups, suggesting that food availability might be above a critical threshold for owl monkeys so that larger groups do not need to extend their foraging areas to meet their energy requirements. Our findings indicate that ranges remain stable over several years as groups visit the same locations of fruit trees within their range. We showed that owl monkeys exhibit a considerable degree of range overlap. However, we suggest that this range overlap might be spatial rather than temporal, which maximizes access to clumped feeding resources in overlapping areas that are used at distinct times, while excluding other males from access to females in exclusively used areas.  相似文献   

12.
13.
《Mammalian Biology》2008,73(1):2-13
We studied the ranging patterns of 10 elephants in and around the Yala protected area complex, southern Sri Lanka, using VHF radio telemetry. All tracked elephants displayed similar ranging patterns. The observed home ranges were small (mean=115.2±64.0 km2) relative to reported home ranges in India, possibly in response to high habitat productivity and abundant perennial water sources. Elephants showed high fidelity to their ranges. Home ranges had relatively large core areas, suggesting intensive use of habitat. No geographically distinct seasonal ranges or migratory behavior was observed. Home range overlap was high, and territoriality was absent. Male musth ranges were considerably larger than non-musth ranges and may signify mate searching. Most elephants ranged both in and outside protected areas, suggesting that resources outside protected areas were important for their survival. Thus, translocating and restricting elephants to protected areas will be detrimental to their survival, as it limits resource access. The ranging patterns of Asian elephants suggest that conservation of the species requires their management both in and outside protected areas.  相似文献   

14.
The aim of the study was to estimate home range areas and distance of movement away from a squaretail coralgrouper (Plectropomus areolatus) spawning aggregation site located within a small-scale 1.5 km2 Marine Protected Area (MPA) in Pohnpei, Micronesia. Fifteen P. areolatus were acoustically tagged and re-located within a ca. 50 km2 search area over a 4-month period that included reproductive and non-reproductive months. All relocated fish were found in areas of moderate to high coral cover either on the fore reef or inside the lagoon in home ranges of 0.048 ± 0.018 km2 (μ ± S.E.). Variability in home range area (0.004–0.12 km2) and distance of movement from aggregation sites following spawning (0.02–23.0 km; 5.3 ± 3.6 km, μ ± S.E.) was observed, but did not appear to be sex specific. Five of the six relocated individuals were found within 0.02–6.1 km of the aggregation. This evidence and that from recent tag-recapture studies of epinephelids suggest that a substantial proportion of individual P. areolatus spawning populations reside within close proximity to their respective aggregation sites. Reproductive populations could be protected by MPAs of moderate scale (10 s of km2) that include aggregation sites, migratory corridors and adjacent home range habitats.  相似文献   

15.
Aim Although satellite tracking has yielded much information regarding the migrations and habitat use of threatened marine species, relatively little has been published about the environmental niche for loggerhead sea turtles Caretta caretta in north‐west Atlantic waters. Location North Carolina, South Carolina and Georgia, USA. Methods We tracked 68 adult female turtles between 1998 and 2008, one of the largest sample sizes to date, for 372.2 ± 210.4 days (mean ± SD). Results We identified two strategies: (1) ‘seasonal’ migrations between summer and winter coastal areas (n = 47), although some turtles made oceanic excursions (n = 4) and (2) occupation of more southerly ‘year‐round’ ranges (n = 18). Seasonal turtles occupied summer home ranges of 645.1 km2 (median, n = 42; using α‐hulls) predominantly north of 35 ° latitude and winter home ranges of 339.0 km2 (n = 24) in a relatively small area on the narrow shelf off North Carolina. We tracked some of these turtles through successive summer (n = 8) and winter (n = 3) seasons, showing inter‐annual home range repeatability to within 14.5 km of summer areas and 10.3 km of winter areas. For year‐round turtles, home ranges were 1889.9 km2. Turtles should be tracked for at least 80 days to reliably estimate the home range size in seasonal habitats. The equivalent minimum duration for ‘year‐round’ turtles is more complex to derive. We define an environmental envelope of the distribution of North American loggerhead turtles: warm waters (between 18.2 and 29.2 °C) on the coastal shelf (in depths of 3.0–89.0 m). Main conclusions Our findings show that adult female loggerhead turtles show predictable, repeatable home range behaviour and do not generally leave waters of the USA, nor the continental shelf (< 200m depth). These data offer insights for future marine management, particularly if they were combined with those from the other management units in the USA.  相似文献   

16.
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 41o and 68oN. 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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
This study examined sex‐specific differences in home range size of adult Indo‐Pacific bottlenose dolphins off Bunbury, Western Australia. We applied a new kernel density estimation approach that accounted for physical barriers to movements. A Bayesian mixture model was developed to estimate a sex effect in home range size with latent group partitioning constrained by association data. A post hoc analysis investigated group partitioning relating to the proportion of time spent in open vs. sheltered waters. From 2007 to 2013, photographic‐identification data were collected along boat‐based systematic transect lines (n = 586). Analyses focused on adult dolphins of known sex (sighted ≥ 30 times; n = 22 males and 34 females). The 95% utilization distributions of males varied between 27 and 187 km2 (; 94.8 ± 48.15) and for females between 20 and 133 km2 (65.6 ± 30.9). The mixture model indicated a 99% probability that males had larger home ranges than females. Dolphins mostly sighted in open waters had larger home ranges than those in sheltered waters. Home ranges of dolphins sighted in sheltered waters overlapped with areas of highest human activity. We suggest that sex differences in home ranges are driven by male mating strategies, and home range size differences between habitats may be influenced by prey availability and predation risk.  相似文献   

20.
Abstract Canada lynx (Lynx canadensis) were listed as a federally threatened species in 14 states at the southern extent of their geographic range in March 2000, with Maine being the only state in the northeastern United States known to support a resident population. Relatively little information is known about the ecology of lynx living at the southern edge of their range, including range requirements, movements, and spatial organization. Basic knowledge of lynx ecology is needed for federal recovery planning efforts. Between 1999 and 2004, we trapped and radiocollared 43 lynx (21 M, 22 F) in northern Maine in an intensively managed and predominantly early successional forested landscape. We estimated diurnal annual and seasonal home-range size for male and female lynx using the 85% fixed-kernel home-range estimator. Annual home ranges of adult male lynx (x̄ = 53.6 km2) were more than twice the size of adult female home ranges (x̄ = 25.7 km2). Home ranges of adult females during snow periods (x̄ = 38.3 km2) were nearly 3 times larger than their snow-free-period ranges (x̄ = 14.3 km2), whereas, snow-free ranges of adult males (x̄ = 58.8 km2) were slightly larger than their snow-period ranges (x̄ = 45.2 km2). We observed a limited amount of home-range overlap among lynx of the same sex (F: x̄ = 17.2%; M: x̄ = 11.8%). Lynx of opposite sex showed more extensive overlap (x̄ = 24.3%). Most home-range shifts of resident lynx were typically not extensive. Based on territory mapping, we estimated a minimum lynx density of 9.2–13.0 lynx/100 km2. We observed lynx spatial ecology and densities that were more similar to northern lynx populations when hares were abundant than to other southern lynx populations, suggesting that region-specific studies under varying habitat conditions and hare densities are needed to ensure realistic recovery goals and effective management of lynx at the southern extent of their range.  相似文献   

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