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1.
Geoffroy's cat Oncifelis geoffroyi is a little-known South American small felid. We report data on the spatial ecology of four adults (two males and two females) that were radiotracked in an area of wet grassland of the Argentine Pampas from February 2000 to April 2001. The mean home range size varied from 248 ha [90% minimum convex polygon (MCP)] to 342 ha (100% MCP), with male home ranges c . 2.5 larger than those of females. Home range overlap averaged 44.7%, and was more extensive between males than between females but it decreased markedly when outliers were excluded. Forest patches were used more than expected by their availability within home ranges. These patches hosted many large defecation sites, possibly acting as 'communication centres' where information was exchanged among individuals in the form of scent marks. Despite the lack of a clear preference for tall grasslands, this was the most frequently used habitat. We argue that natural grasslands in the Pampas ecoregion are important for O. geoffroyi and that their alteration can affect the conservation status of this cat. The comparison of our data with those reported previously suggests that Geoffroy's cat can show a certain degree of flexibility in its spatial behaviour.  相似文献   

2.
《新西兰生态学杂志》2011,23(2):149-159
We monitored the behaviour of 62 radio-collared ferrets and 25 radio-collared cats in dry, tussock grassland habitat in New Zealand's South Island. The total home range of adult male ferrets (102 ± 58 ha, mean ± 1 s.d.) was marginally greater than that of females (76 ± 48 ha), and averaged 90 ± 55 ha. Male ferret core ranges (27 ± 15 ha) were larger than those of females (16 ± 8 ha). Adult cat home ranges were similar between sexes, and were larger and more variable than those of ferrets (225 ± 209 ha). Core range size of cats was similar between sexes and averaged 54 ± 24 ha. The upper 95% confidence limits of the mean home range lengths of adult ferrets and cats were 2.7 km and 5.1 km, respectively, indicating the width of buffer zones where predator control should be extended to protect the boundaries of areas targeted for predator control in dry, tussock grasslands. Although core areas were mostly discrete, home ranges were distributed randomly, and animals that shared space neither avoided nor attracted each other. Little evidence of territoriality may be related to high densities of primary prey. Too few cats were monitored to determine territoriality. Ferrets used at least 9.4 ± 3.2 dens, and cats used 11.5 ± 3.0 dens during the study. Although 71% of dens were used only once, some were used up to nine times. Day time resting by ferrets was mostly solitary. If transmission of bovine Tb occurs between adult ferrets, simultaneous sharing of dens during the day is unlikely to be a significant mode of transmission in this habitat. We were unable to determine the extent of den sharing by cats. Cats occupied den sites with more shrubs and rocks compared with ferrets. Predator control stations in dry tussock grassland habitat may therefore be more effective at killing cats than ferrets if placed in shrubby, rocky areas.  相似文献   

3.
There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track‐based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long‐term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty‐four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long‐term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long‐term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed.  相似文献   

4.
Alien mammalian carnivores have contributed disproportionately to global loss of biodiversity. In Australia, predation by the feral cat and red fox is one of the most significant causes of the decline of native vertebrates. To discover why cats have greater impacts on prey than native predators, we compared the ecology of the feral cat to a marsupial counterpart, the spotted-tailed quoll. Individual prey are 20–200 times more likely to encounter feral cats, because of the combined effects of cats'' higher population densities, greater intensity of home-range use and broader habitat preferences. These characteristics also mean that the costs to the prey of adopting anti-predator behaviours against feral cats are likely to be much higher than adopting such behaviours in response to spotted-tailed quolls, due to the reliability and ubiquity of feral cat cues. These results help explain the devastating impacts of cats on wildlife in Australia and other parts of the world.  相似文献   

5.
No information is currently available on the space needs of hairy-eared dwarf lemurs (Allocebus trichotis), classified as Data Deficient. The data are crucial for their conservation and comparison with other nocturnal primates. I conducted the first radiotracking study of the species from January to December 2007 in the Analamazaotra Special Reserve of Central Eastern Madagascar. I used nocturnal focal individual follows and daytime nest locations to determine home ranges. I followed 1 full sleeping group (4 adults) for 8 mo and 1 partial sleeping group (2 females) for 3 mo. Group home ranges, calculated via 100% minimum convex polygons (MCP), were 35.5 ha and 16.0 ha, respectively. The 95% kernel method of analysis yielded group home ranges of 15.2 ha and 7.1 ha respectively. The mean home range size for individuals was 15.4 ha (MCP) and 5.4 ha (kernel). This is much larger than for other Cheirogaleidae and could be due to a more insectivorous diet or the use of patchily distributed gum-producing trees. There were small nonsignificant monthly variations in home range size. The mean home range size per individual per month was 5.2 ha (MCP) and 2.2 ha (kernel). Important individual differences in overall and monthly home range size could be due to variations in the individual reproductive cycles and survival strategies. Overlap analyses and the lack of sexual difference in home range size suggest the social unit is a family or multimale/multifemale sleeping group with monogamous or promiscuous mating. The Analamazaotra Special Reserve probably holds ca. 100 adult individuals. Additional research is urgently needed to clarify the habitat needs of this rare species.  相似文献   

6.
Sympatric species can minimise interspecific competition by spatial avoidance or by altering their temporal activity to reduce encounter rates. The Tasmanian devil (Sarcophilus harrisii), the largest carnivorous marsupial, coexists with the smaller spotted‐tailed quoll (Dasyurus maculatus) in Tasmania, Australia. Quolls may be susceptible to interspecific competition from devils, because they utilise similar habitats, consume similar prey species and are displaced by devils at food sources. Such competition might cause quolls to spatially or temporally avoid devils. To investigate whether spatial or temporal avoidance occurred, we deployed GPS collars on sympatric devils and quolls and conducted a camera survey at a site in northwest Tasmania where the devil population was not affected by devil facial tumour disease. GPS tracking coincided with the lactation period when devils and quolls had young in dens and continued until weaning occurred. We found little spatial segregation of home range and core area placement between devils and quolls and among devils. Quolls showed more spatial segregation within the sexes than between them. Devils had larger home ranges than quolls. Male devils had larger home ranges than females, but there was no difference in home range size between the sexes of quolls. Females of both species travelled significantly further per night than did males. There was moderate temporal partitioning between the two species: devil activity peaked after dusk and devils remained active until the early morning, while quoll activity showed distinct peaks around dusk and dawn. In conclusion, quolls did not spatially avoid devils but moderate temporal partitioning occurred. It is plausible that quolls are active at different times of the diel cycle to reduce encountering devils, but further studies are needed to resolve the cause of this temporal partitioning.  相似文献   

7.
The huemul Hippocamelus bisulcus is an endangered species of deer occupying temperate woodland habitats in the Andes of southern Chile and Argentina. Continuing declines due to a combination of hunting and habitat loss have created a need for more conservation measures. However, current information on ranging behaviour, dispersal and seasonal movements is very limited. Three sites were therefore selected in Aysén, Chilean Patagonia, to study the movements and habitat associations of huemul. Although seasonal migrations in elevation had been reported previously for the species, we found the extent of seasonal movement limited, much less than that reported for other deer species in mountainous environments. Huemul selected mid-slope elevations, and the winter ranges of most animals overlapped summer ranges. The extent of the seasonal movements that were undertaken were, however, the greatest at the highest site and insignificant at the lowest site. Previously published information shows that habitats used by huemul follow a latitudinal gradient in elevation (reducing c . 100 m °S−1 in latitude), and our results suggest that seasonal movements are likely to be greater in sites above this line. The mean range size differed between sites, ranging from 357 to 656 ha (mean 444 ha; median 506 ha). These estimates excluded long-distance (>5 km) movements, which were infrequent.  相似文献   

8.
Orangutan Home Range Size and Its Determinants in a Sumatran Swamp Forest   总被引:4,自引:0,他引:4  
Orangutans (Pongo pygmaeus) in a Sumatran swamp forest used home ranges far larger than any described so far for the species, in spite of living at the highest density on record. Although it was difficult to estimate home range sizes, minimum reliably estimated home range sizes for adult females are ca. 850 ha, whereas subadult and adult males used ranges of at least ca. 2500 ha, and perhaps much more. Range overlap was very high: up to 16 adult females, 9 adult males and at least 15 subadult males were seen within a single 4-ha square in the center of the study area. We found no evidence for the use of seasonally distincthome ranges—commuters—, and only some subadult males may have been transients—wanderers—without a stable home range. The large size of the home ranges is attributed to the coarse grain of the habitat mosaic, with orangutans converging on parts with a high density of favored fruit trees. Orangutans at this swamp forest included a variety of habitat types within their ranges.  相似文献   

9.
Most cooperative breeding bird species live in family groups that are formed through the prolonged association of offspring with their parents. Research into cooperative families has in particular investigated the balance between cooperation and conflict over reproductive decisions. As a consequence of this research focus, social interactions among group members outside the breeding season are rarely studied, despite the fact that they are likely to be crucial for social decisions. We investigated the social dynamics and ranging behaviour of the family group living cooperatively breeding apostlebird ( Struthidea cinerea ) outside the breeding season. Group size changed between, but not within, the seasons, being smaller during the breeding season than in the winter season. This change in group size was a consequence of breeding groups merging after breeding, then splitting again before the next breeding season. While breeding groups used small, non-overlapping home ranges (      = 113 ha) around the nesting site, during winter groups moved up to 1200 ha (      = 598 ha), and interacted frequently with up to four other winter groups. In particular large groups often joined together during winter and spent up to 50% of their time associating with other large winter groups. This apparent fission-fusion system facilitated the exchange of group members, offering the possibility to form new breeding coalitions and new groups. The results of this study suggest that behaviour outside the breeding season can be of considerable importance to the social dynamics of both families and cooperative breeding in such systems.  相似文献   

10.
B. Georgii 《Oecologia》1980,47(2):278-285
Summary From 1976 to 1978, ten female red deer in the northern parts of the Bavarian Alps (Southern West Germany) were fitted with transmitter collars. Seasonal movements, the home range patterns, and habitat utilization as a function of the habitat structure were examined. While some animals remained in the lowlands throughout the year, others move between two or even three different areas seasonally. The average size of the home range was 65 ha during winter, 167 ha in spring and autumn and 121 ha in summer. The overlap of home ranges of different individuals ranged from 18 to 100%. In habitats with a patchy vegetation structure the home ranges were used more uniformly, whereas in habitats with a distinct separation of large woods and meadows home ranges show diurnal and nocturnal activity centres respectively.  相似文献   

11.
Because space‐use patterns are a key aspect of the ecology and distribution of species, identifying factors associated with variation in size of territories and home ranges has been central to studies on population ecology. Space use might vary in response to extrinsic factors like habitat quality and to intrinsic factors like physical condition and individual aggressiveness. However, the role of these factors has been poorly documented in the tropics, particularly in high‐elevation bird species. We report the home‐range size of a Neotropical Andean bird, the gray‐browed brush finch (Arremon assimilis), and evaluate the role of physical condition in explaining variation in home‐range size among individuals. We performed spot mapping to estimate the home ranges of 14 territorial males in Bogotá, Colombia, using minimum convex polygons (MCP) and 95% kernel density estimators (KDE). The mean home‐range size estimated for the 100% MCP was 0.522 ± 0.305 ha (range = 0.15–1.18 ha), whereas the 95% KDE estimation was 0.504 ± 0.471 ha (range = 0.13–1.88). We calculated the real mass index of each bird as a proxy of physical condition to assess whether individuals in better physical condition had larger home ranges. Because we found no relation between our estimations of physical condition and home‐range size, we conclude that space use in this species might depend more on ecological factors such as habitat quality or neighbor density than on individual traits. Abstract in French is available with online material.  相似文献   

12.
Female promiscuity is common among mammals but its advantages, particularly for marsupials, remain unclear. Using microsatellite DNA from pouch young of known mothers, we identified the most likely fathers of 25 wild spotted-tailed quolls ( Dasyurus maculatus ) from six litters. We aimed to determine whether young within the same litter had different fathers, and whether breeding success of males was associated with large body mass (consistent with inter-male competition) or scrotal width (consistent with sperm competition). We also explored the possible influence of promiscuity on relatedness within litters. Finally, we used data on paternity and relatedness to make inferences regarding movement and dispersal.
Four litters were sired by more than one male, and three males sired offspring in more than one litter. Known fathers had higher body mass, but not scrotal width, than males of unknown paternity status, suggesting that males may compete for access to females. Sires were less related to dams than expected by chance, and litters with multiple paternity had lower relatedness than litters sired by a single male.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 1–7.  相似文献   

13.
Knowledge about the spatial ecology of small mammals in relation to fire history in arid zones in general and Australia in particular is limited. Here, we report data on the spatial ecology of the brush-tailed mulgara Dasycercus blythi in the hummock grasslands of Ulu r u – Kata Tju t a National Park during winter 2006, the beginning of the breeding season for this species. About 73% of the study area had been burnt in 2002 and spinifex cover was sparse. Mulgaras Marsupialia: Dasyuridae (six males and three females) were implanted with radio-transmitters and monitored daily for between 6 and 55 days. All mulgaras appeared to use defined home ranges, which overlapped extensively with those of several neighbours. Spatial overlap occurred between as well as within sexes. On average, males (25.5 ha) occupied significantly larger home ranges than females (10.8 ha). Mulgaras used a number of burrows within home ranges and several were used by more than one individual. Moreover, occasionally, two individuals used the same burrow simultaneously. Home ranges and burrows encompassed both mature spinifex Triodia basedowii and open regrowth areas and mulgaras did not exhibit a significant preference for either habitat type. However, three males were killed by introduced-predators and they all lived predominantly in the open regrowth area. We conclude that mulgaras do not select the dense cover of mature spinifex habitat, and might be subjected to increased risk from introduced predators, especially following fire.  相似文献   

14.
ABSTRACT.   Identifying and protecting breeding habitat for imperiled species requires an understanding of the spatial and temporal movements of breeding individuals. During the 2003 and 2004 breeding seasons, we examined space use by Piping Plovers ( Charadrius melodus ) in the federally endangered Great Lakes population. We used coordinate geometry to estimate home range sizes of individual birds and examined relationships between home range size and breeding stage (incubation versus chick rearing), year, sex, number of locations, minimum plover age, distance to the nearest nest, and human beach use (high, medium, or low). The mean size of home ranges of Piping Plovers that fledged at least one chick was 2.9 ± 0.5 (SE) ha (range = 0.4–11.2 ha), and the mean linear beach distance traversed was 475 ± 53 m (range = 130–1435 m). Individuals used 3 times more beach area and 1.5 times more shoreline distance in 2003 than in 2004. Females used smaller areas than males overall and during chick rearing. Home ranges were smallest on beaches with low public use, suggesting that human disturbance may cause greater movement by individual plovers and that larger protected areas may be warranted on beaches frequented by the public to minimize disturbance to breeding birds. Our results demonstrate that nesting Great Lakes Piping Plovers occupy relatively small ranges and, therefore, that even relatively small areas of suitable habitat can have a high conservation value for this endangered population. However, the total area of habitat used varied substantially among individuals, and this should be considered when protecting habitat for the species.  相似文献   

15.
The southernmost subspecies of pampas deer Ozotocerus bezoarticus celer is an endemic and endangered cervid of the Argentine Pampas. The aim of our study was to describe the habitat use of this deer on the coast of Samborombón Bay. Twelve adult pampas deer (seven female and five male) were radiotracked and their home-range sizes and habitat selection studied from 1995 to 2001. The mean home-range size was 898±181 ha, and the core area was concentrated in 22% of their range. The home-range size of males was three times larger than that of females (1422 vs. 523 ha). Deer home ranges overlapped extensively. No sex differences were found regarding habitat selection. Celtis tala forests and Spartina densiflora grasslands were used more than expected by their availability, while wetlands, coastal grasslands and Salicornia ambigua beaches were avoided. Their habitat selection was affected by cattle presence, suggesting avoidance: they tended to use areas free of cattle, and their home ranges were larger when cattle were absent. An action plan for this endangered population of pampas deer should include initiatives involving private landowners in pampas deer conservation, the use of fire and cattle grazing management tools to improve deer habitat, and studies to provide biological and health data related to pampas deer coexistence with cattle.  相似文献   

16.
In 2005–2008, we radio-tracked 17 foxes in rural areas of Southern Germany. The mean home range size was 76.6 ha (95% MCP) or 138.9 ha (95% fixed kernel), and the built-up area formed an integral part of the home range. Home ranges of juvenile foxes were significantly smaller than home ranges of adult foxes. Gender-specific differences among adult foxes were not established. A minimum population density of 2.7 foxes per km2 and summer densities of up to 13.4 foxes per km2 were calculated. Therefore, the fox density was three to eight times higher than that of strictly rural foxes. Daytime resting sites of foxes were mostly found in forests (62.2%) and reedbed areas (20.6%). Of the resting sites, 14.8% were situated inside settlements, in fallow gardens or gardens of residents. During the day, foxes exhibited habitat preferences for forests and reedbed areas. A habitat structure that offers plenty of cover or dense vegetation is essential for its selection as a safe resting site. If this basic requirement is fulfilled, foxes also choose resting sites within settlements, and are not disturbed by human presence.  相似文献   

17.
In a radiotelemetric study, we analysed space use of 24 female specimens (14 family groups and 14 nonreproductive yearling females) out of 23 wild boar groups for periods between 3 and 39 months. Generally, wild boar used relatively small areas, showed high site fidelity but also a strong individual variation of home ranges, indicating a high flexibility in space use. Although age-specific differences were not statistically significant, female yearlings tended to have larger mean annual home ranges (1,185 ha MCP) than animals ranging in family groups (771 ha). Yearlings also showed a stronger shifting from spring to summer home ranges (2,345 m) and a tendency towards larger home range sizes in summer (791 ha MCP), compared to family groups (shift 1,766 m, MCP 461 ha). Yearlings displayed a dislocation of about 1 km of the annual centre in the first year after dividing from the mother. In contrast, in adults older than 2 years, the dislocation of the annual center was only 240 m.  相似文献   

18.
Lepilemur mittermeieri, a little‐studied sportive lemur of north‐west Madagascar, endemic to the Ampasindava Peninsula, faces habitat loss through forest degradation and rapid fragmentation. Understanding its habitat requirement is the first step toward preservation of this threatened forest‐dependent species. In this study, we gathered data on the use of space and home range characteristics of L. mittermeieri. We studied individuals from early March to the end of June 2015 and 2016, in three sites of the Ampasindava peninsula. We radio‐tracked 15 individuals to obtain detailed information on the size and location of home ranges (around 450 hr of tracking). Direct observation and morphometric measurements provided additional data sets. Both kernel density estimation (KDE) and minimum convex polygon (MCP) methods yielded similar home range sizes (an average of 2.01 ha with KDE method and 1.96 ha with MCP method). We did not find differences in home range size between males and females, with respect to forest type or proximity to the forest edge. Home ranges overlapped and individuals showed low levels of territoriality. We highlighted a sexually‐dimorphic trait: males have longer upper canine than females. Our results constitute the first set of ecological information on Lepilemur mittermeieri and could be the basis for a conservation strategy for this endangered species with a very small distribution area.  相似文献   

19.
The manner by which animals use space and select resources can have important management consequences. We studied patterns of habitat selection by northern bobwhites (Colinus virginianus) on Babcock-Webb Wildlife Management Area, Charlotte County, Florida and evaluated factors influencing the sizes of their home ranges. A total of 1,245 radio-tagged bobwhites were monitored for 19,467 radio days during 2002–2007. The mean ( ± 1 SE) annual home range size, estimated using the Kernel density method, was 88.43 ( ± 6.16) ha and did not differ between genders. Winter home ranges of bobwhites (69.27 ± 4.92 ha) were generally larger than summer home ranges (53.90 ± 4.93 ha). Annual and winter home ranges were smaller for bobwhites whose ranges contained food plots compared to those that did not; however, the presence of food plots did not influence summer home ranges. We used distance-based methods to investigate habitat selection by bobwhites at two scales: selection of home ranges within the study site (second-order selection) and selection of habitats within home ranges (third-order selection). Across both scales, bobwhites generally preferred food plots and dry prairie habitat and avoided wet prairies and roads. This pattern was generally consistent between genders and across years. Our data indicate that management practices aimed at increasing and maintaining a matrix of food plots and dry prairie habitat would provide the most favorable environment for bobwhites.  相似文献   

20.
Accuracy of resource selection functions across spatial scales   总被引:2,自引:0,他引:2  
Resource selection functions (RSFs) can be used to map suitable habitat of a species based on predicted probability of use. The spatial scale may affect accuracy of such predictions. To provide guidance as to which spatial extent or grain is appropriate and most accurate for animals, we used the concept of hierarchical selection orders to dictate extent and grain. We conducted a meta-analysis from 123 RSF studies of 886 species to identify differences in prediction success that might be expected for five selection orders. Many studies do not constrain spatial extent to the grain of the next broader selection order in the hierarchy, mixing scaling effects. Thus, we also compared accuracy of single- vs. multiple-grain RSFs developed at the unconstrained extent of an entire study area. Results suggested that the geographical range of a species was the easiest to predict of the selection orders. At smaller scales within the geographical range, use of a site was easier to predict when environmental variables were measured at a grain equivalent to the home-range size or a microhabitat feature required for reproduction or resting. Selection of patches within home ranges and locations of populations was often more difficult to predict. Multiple-grain RSFs were more predictive than single-grain RSFs when the entire study area was considered available. Models with variables measured at both small and large (> 100 ha) grains were usually most predictive, even for many species with small home ranges. Multiple-grain models may be particularly important for species with moderate dispersal abilities in habitat fragments surrounded by an unsuitable matrix. We recommend studies should no longer address only one grain to map animal species distributions.  相似文献   

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