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1.
Five adult male Jaguars and a translocated subadult female Jaguar were captured and followed by radio-telemetry in Cockscomb Basin, Belize. One adult male Jaguar, two resident female Jaguars, and a Puma were followed only by their tracks. Radio-collared males maintained overlapping ranges of 28–40 km2 , while resident females moved in minimum areas of 10 km2 within the ranges of individual males. Despite range overlap, evidence of aggression or sign of more than one large cat in the same area simultaneously was uncommon. Such avoidance behaviour suggested some means of communication. Visual marking in the form of faeces and scrapes were found uncovered along roads and trails in areas of overlap between the cats; such marking could have helped in boundary delineation as well as spatial and temporal positioning. Males often remained in small areas of 2·5 km2 for up to two weeks, a behaviour made possible by abundant prey. This behaviour may have facilitated avoidance with other Jaguars. Faecal analysis indicated opportunistic feeding on 17 prey species. Armadillo, Paca and brocket deer accounted for 94% of the available terrestrial prey and comprised 70% of the identified prey in the faeces. All Jaguars were primarily nocturnal, though activity varied between animals. The translocated female showed changes in activity patterns when feeding upon cattle. At least one Puma travelled within the ranges of several male Jaguars and appeared to be feeding on smaller prey items. The behavioural and ecological plasticity exhibited by the Jaguars in this study is beneficial for an animal whose habitat is rapidly diminishing. 相似文献
2.
Residence and movement patterns of cownose rays Rhinoptera bonasus within a south-west Florida estuary 总被引:1,自引:0,他引:1
Between July 2003 and November 2004, 21 cownose rays Rhinoptera bonasus were tagged and tracked within Pine Island Sound estuary, Florida, using passive acoustic telemetry. Residence time of individuals ranged between 1 and 102 days. No relationship was detected between ray activity and tidal stage or time of day. Minimum convex polygons (MCP) and kernel utilization distributions (KUD) were calculated over several time frames to demonstrate the extent of an animal's home range and core areas of use. Total MCPs ranged between 0·81 and 71·78 km2 (mean = 22·01 km2 ), with daily MCPs as large as 25·8 km2 . Total 95% KUDs ranged between 0·18 and 62·44 km2 (mean = 22·63 km2 ), while total 50% KUDs were smaller, ranging from 0·09 to 9·68 km2 (mean = 3·33 km2 ). Both MCP and KUD areas exhibited a positive relationship with residence time and R. bonasus size. As mobile, pelagic swimmers capable of traversing large distances, these data show that cownose rays travel extensively throughout this estuary, yet may remain within very small areas for extended periods. 相似文献
3.
Urs Breitenmoser Petra Kavczensky Michael Dötterer Christine Breitenmoser-Würsten Simon Capt Frank Bernhart Martin Liberek 《Journal of Zoology》1993,231(3):449-464
We monitored seven resident (three males and four females) and six dispersing subadult Eurasian lynx from to in a population that was re-introduced to the Swiss Jura Mountains in the early 1970s. Home-range areas of the neighbouring adults were 71–281 km2 , and significant core areas 34–252 km2 . Males occupied significantly larger areas than females. Home-range overlap was 9% for neighbouring males and 3%) for females. Core areas of males did touch, but those of females were clearly separated. Each male's home range covered those of one or two females. Population density was 0.94 lynx/100 km2 for resident animals. Pre-dispersal mortality was estimated to be 50%. Juveniles dispersed from their mothers' home area at the age of 10 months. Of six monitored subadults. only one survived the first year of independence. Human-caused mortality (traffic accidents. illegal killing) was high. This was also the case among resident adults. This might be a threat to the long-term survival of the reintroduced population. 相似文献
4.
We conducted wet [26 March–4 April 2003 (Apr03)] and dry [1–8 November 2005 (Nov05)] season aerial surveys of African elephants ( Loxodonta africana Blumenbach) in the Caprivi Strip, Namibia to provide an updated status report on elephant numbers and distribution and assist with a historical analysis of elephant distribution and abundance in the Caprivi Strip. During the wet season when water was available in seasonal pans, elephants were widely distributed throughout the survey area. In contrast, during the dry season, a majority of elephant herds occurred within 30 km of the perennial Kwando, Linyanti and Okavango rivers and few herds occurred within the West Caprivi Game Reserve where water in the seasonal pans was limited. We estimated 5318 elephants for the 7731-km2 survey area (0.71 elephants km−2 ) for the Apr03 wet season survey and 6474 elephants for the 8597-km2 survey area (0.75 elephants km−2 ) for the Nov05 dry season survey. Based on our aerial surveys and reports of elephant numbers and distribution from historical aerial surveys and telemetry studies, civil war, veterinary fences and human activities appear to have effected changes in African elephant abundance, distribution and movements in the Caprivi Strip, Namibia since 1988 when the first comprehensive aerial surveys were conducted. 相似文献
5.
In addition to the threats of habitat loss and degradation, adult males of the Asian elephant Elephas maximus also face greater threats from ivory poaching and conflict with humans. To understand the impact of these threats, conservationists need robust estimates of abundance and vital rates specifically for the adult male segment of elephant populations. By integrating the identification of individual male elephants in a population from distinct morphology and natural markings, with modern capture–recapture (CR) sampling designs, it is possible to estimate various demographic parameters that are otherwise difficult to obtain from this long-lived and wide-ranging megaherbivore. In this study, we developed systematic individual identification protocols and integrated them into CR sampling designs to obtain capture histories and thereby estimate the abundance of adult bull elephants in a globally important population in southern India. We validated these estimates against those obtained from an independent method combining line-transect density estimates with age–sex composition data for elephants. The sampled population was open to gains and losses between sampling occasions. The abundance of adult males in the 176 km2 study area was (SÊ ) = 134(14.20) and they comprised 14% (±1%) of the total elephant population. Time-specific abundance estimates for each sampling occasion showed a distinct increase in adult male numbers over the sampling period, explained by seasonal patterns of local migration. CR-based estimates for adult male abundance closely matched estimates from distance-based methods. Thus, while providing abundance data of comparable rigour and precision, photographic CR methods permit estimation of demographic parameters for the Asian elephant that are both urgently needed and difficult to obtain. 相似文献
6.
Jaguar spacing, activity and habitat use in a seasonally flooded environment in Brazil 总被引:1,自引:0,他引:1
Between July 1980 and February 1984, six jaguars (two males, four females) were fitted with radio-collars and monitored for a cumulative total of 105 months, in the Pantanal region of southwestern Brazil. Mean home range size (minimum convex polygon) for five of them (one male, four females) was 142- 1 km2 . Mean home range size during the dry season was 54·3 km2 , whereas in the wet season it was significantly smaller, 12·8 km2 . Mean home range overlap of the four females was 42%. Use of gallery forest and forest patches exceeded the availability of these habitat types in the animals' home ranges, whereas open forest and grassland were used less than expected on the basis of their availability. Mean distance moved between locations on consecutive days was 2·4 km (0.2-10·4 km). The mean one-day movement of the male jaguar was significantly (P<0·001) larger than that of the females. Mean distance travelled by all animals during one-day intervals in the dry season was significantly greater (P<0·001) than that travelled in other months. Jaguars were more active during daytime than night-time (P<0·001). Overall level of activity for the wet season did not differ from that of the dry season. With their larger body size, jaguars in the Pantanal may require more food than jaguars in other areas of the species' range. This, in addition to differences in prey availability and the annual availability of dry land, appear to influence the difference in home range size between jaguar populations. 相似文献
7.
Autumn migration and wintering areas of Peregrine Falcons Falco peregrinus nesting on the Kola Peninsula, northern Russia 总被引:1,自引:0,他引:1
Sergei A. Ganusevich Thomas L. Maechtle William S. Seegar Michael A. Yates Michael J. McGrady Mark Fuller Linda Schueck Jim Dayton & Charles J. Henny 《Ibis》2004,146(2):291-297
Four female Peregrine Falcons Falco peregrinus breeding on the Kola Peninsula, Russia, were fitted with satellite-received transmitters in 1994. Their breeding home ranges averaged 1175 (sd = ±714) km2 , and overlapped considerably. All left their breeding grounds in September and migrated generally south-west along the Baltic Sea. The mean travel rate for three falcons was 190 km/day. Two Falcons wintered on the coasts of France and in southern Spain, which were, respectively, 2909 and 4262 km from their breeding sites. Data on migration routes suggested that Falcons took a near-direct route to the wintering areas. No prolonged stopovers were apparent. The 90% minimum convex polygon winter range of a bird that migrated to Spain encompassed 213 km2 ( n = 54). The area of the 50% minimum convex polygon was 21.5 km2 ( n = 29). Data from this study agree with others from North America that show that Falcons breeding in a single area do not necessarily follow the same migratory path southward and do not necessarily use the same wintering grounds. 相似文献
8.
Home ranges and habitat use are described for three adult female, one adult male, and one subadult male wolverines in the Kluane Game Sanctuary, Yukon. When long distance excursions are not included, home ranges of wolverines in the Kluane Game Sanctuary were between 76 and 269 km2 for females and 209 and 269 km2 for males. Habitat use of females was similar to habitat availability. Males used subalpine coniferous habitats more frequently than other habitat types during winter. Although individual variation in the use of forest cover types, aspects, slopes and elevations was apparent, seasonal use did not differ from availability for each sex. Within the 1590 km2 study area, three adult males and six adult females were present, corresponding to a density of one resident wolverine 177 km-2 . 相似文献
9.
Relationships between home-range size, sex and season with reference to the mating system of the Houbara Bustard Chlamydotis undulata undulata 总被引:1,自引:0,他引:1
Yves Hingrat Michel Saint Jalme Frédéric Ysnel Fredéric Lacroix John Seabury & Pierrick Rautureau 《Ibis》2004,146(2):314-322
This paper presents observations of Houbara Bustard Chlamydotis undulata undulata home-range, in the semi-desert steppe of eastern Morocco. Home-ranges were calculated from radiotagged birds using the fixed kernel method (LSCV). The mean annual home-range of males (17 km2 ) was smaller than that of females (146 km2 ; P < 0.001). The majority of male home-ranges had a unimodal distribution (86%), whereas 67% of female home-ranges were multimodal. Consequently, the amplitude of female movements was larger (mean: 44 km/13 km; P < 0.002). In spring, male home-ranges decreased in size around display sites (8 km2 ) and many of them overlapped considerably. Display sites show an aggregative distribution ( P < 0.001) and a single female reproductive range may contain the display sites of several males. The data fulfil the definition of an exploded lek social structure. In our study, C. u. undulata appears to be sedentary with relatively limited home-ranges. Successive years of fidelity to home-ranges indicate that adults are not nomadic. 相似文献
10.
L. L. Marker A. J. Dickman M. G. L. Mills R. M. Jeo & D. W. Macdonald 《Journal of Zoology》2008,274(3):226-238
Knowledge of a species' ranging behaviour is both fundamental to understanding its behavioural ecology and a prerequisite to planning its management. Few data exist on the spatial ecology of cheetahs Acinonyx jubatus outside protected areas, but such areas are particularly important to their conservation. Cheetahs on Namibian farmlands occupied exceptionally large home ranges, averaging 1651 km2 (±1594 km2 ), with no detectable effect of sex, social grouping or seasonality. Despite such large ranges, cheetahs tended to utilize intensively only a small fraction of that area: 50% of the fixes were located within an average of 13.9±5.3% of the home range. Ranges were not exclusive, overlapping on average by 15.8±17.0%, with male cheetahs showing more intra-sexual range overlap than did females. Coalitions of males appeared to select for a dense, prey-rich habitat, but this preference was not apparent for other social groupings. Conflict with humans is an important contributor to the species' decline, and these large, overlapping cheetah home ranges result in the movements of each individual cheetah encompassing many farms (21 based on the average home-range size). Consequently, many cheetahs may be exposed to a minority of farmers attempting to kill them, and also that many farmers may see the same cheetahs, thereby gaining an exaggerated impression of their abundance. Conservation priorities for cheetahs outside protected areas are the development of techniques for conflict resolution, as well as the maintenance and restoration of suitable habitat and promotion of land-management practices compatible with the continued existence of large carnivores. 相似文献
11.
Heard but not seen: an acoustic survey of the African forest elephant population at Kakum Conservation Area, Ghana 总被引:1,自引:0,他引:1
Mya E. Thompson Steven J. Schwager Katharine B. Payne 《African Journal of Ecology》2010,48(1):224-231
This study, designed to survey forest elephants ( Loxodonta africana cyclotis ) at Kakum Conservation Area, Ghana, is the first to apply acoustic methods to elephant abundance estimation and to compare results with independent survey estimates. Nine acoustic sensors gathered sound continuously for 38 days. Low-frequency calling rates have been established as useful elephant abundance indices at a Namibian watering hole and a central African forest clearing. In this study, we estimated elephant population size by applying an abundance index model and detection function developed in central Africa to data from simultaneous sampling periods on Kakum sensors. The sensor array recorded an average of 1.81 calls per 20-min sampling period from an effective detection area averaging 10.27 km2 . The resulting estimate of 294 elephants (95% CI: 259–329) falls within confidence bounds of recent dung-based surveys. An extended acoustic model, estimating the frequency with which elephants are silent when present, yields an estimate of 350 elephants (95% CI: 315–384). Acoustic survey confidence intervals are at least half as wide as those from dung-based surveys. This study demonstrates that acoustic surveying is a valuable tool for estimating elephant abundance, as well as for detecting other vocal species and anthropogenic noises that may be associated with poaching. 相似文献
12.
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). 相似文献
13.
Wintering site fidelity and movement patterns of Western Sandpipers Calidris mauri in the San Francisco Bay estuary 总被引:1,自引:0,他引:1
Western Sandpipers Calidris mauri are the most numerous shorebird species in the San Francisco Bay estuary during winter. A sample of 106 Western Sandpipers was captured in mist nets and radio-marked with 1-g transmitters to examine their wintering site fidelity and movements. Differences in distances moved, home range extent and core area size were examined by age, sex, season, site, time of day and tide. All birds remained in the south San Francisco Bay region during winter and exhibited strong site fidelity, with a mean home range of 22.0 km2 or only 8% of the study area. First-year birds had larger home ranges (26.6 ± 3.6 km2 ) than adults (17.2 ± 2.5 km2 ) in winter, but home range sizes of males and females were not significantly different in any period. Home range sizes were similar between seasons, but core areas were smaller in spring (6.3 ± 1.2 km2 ) than in early (9.6 ± 4.0 km2 ) or late (11.6 ± 1.6 km2 ) winter. Movements and home range size were similar for radio-marked birds located during day and night. The high degree of regional and local site fidelity demonstrated that the mixture of natural mud fiats and artificial salt ponds in southern San Francisco Bay provided sufficient resources for large wintering populations of Western Sandpipers. 相似文献
14.
White rhinoceros range size was ascertained telemetrically in the south-western Kruger National Park. The mean annual range size of territorial males was 9.86 km2 compared to 22.83 km2 for adult females. White rhinoceros females' summer wet season range was larger (21.44 km2 ) than the winter dry season range (11.64 km2 ). It is argued that abundant field-water during the wet season enables animals to range further from permanent water supplies and to utilize larger foraging areas. White rhinoceros have core areas in their individual ranges that usually are situated along riverbanks in the preferred grazing regions. These core areas also include some favourite resting spots on high-lying areas. White rhinoceros range sizes in the south-western Kruger National Park were similar to those of other reserves with comparable white rhinoceros densities. In the Umfolozi Game Reserve, which has a higher white rhinoceros density than the Kruger National Park, the individual ranges are much smaller. 相似文献
15.
JACKY JUDAS OLIVIER COMBREAU MARK LAWRENCE MOHAMMED SALEH FREDERIC LAUNAY & GAO XINGYI 《Ibis》2006,148(2):343-351
Four adult male Asian Houbara Bustards Chlamydotis macqueenii were caught on their breeding grounds in the Gobi Desert of China and tracked by satellite from July 2000 for from 5 months to > 3.5 years. Wintering areas were identified for two individuals, one on the Turkmenistan/Uzbekistan border in the Amur-Darya valley, the second at the Iran/Turkmenistan border. One individual used the same wintering and breeding areas for three consecutive years. Overall departure dates from breeding grounds ranged from 29 September to 14 October, with arrival on wintering quarters from 23 October to 7 November. Birds left their wintering grounds between 2 and 21 March and reached their breeding areas between 11 and 21 April. The mean overall migration distance was 3935 km (sd = ± 229, n = 9). Houbara Bustards mainly followed steppe areas to migrate avoiding the highest elevations of the Himalayan massif and travelling 267 km/day on average. Pre-breeding migration lasted longer than post-breeding and included more and longer stopovers. The Taukum Desert and Jungar Basin are critical areas for migration of eastern Houbara populations. Breeding range, used for 5.5 months, was 274 km2 (sd = ± 53, n = 4), whereas wintering range, used for around 4 months a year, was 76 km2 (sd = ± 22, n = 3). Range use pattern appeared similar for Asian Houbara released in central Saudi Arabia, but differed from the African Houbara Bustard. More investigations are required to determine the effects of food availability and meteorological conditions on the migration pattern and on the use of stopovers by Asian Houbara Bustards. 相似文献
16.
C. R. GOLDSPINK R. K. HOLLAND G. SWEET & R. STJERNSTEDT 《African Journal of Ecology》1998,36(1):23-33
This study (1994) examines the distribution and abundance of puku ( Kobus vardoni Livingstone) in Kasanka National Park (area=470 km2 ) Zambia, following five years of anti‐poaching control. The puku is an important 'flagship' species for the park. Most puku were confined to a limited number ( n =19) of river floodplains and dambos (total area=20·29 km2 ) towards the centre of the park. Large areas of 'suitable' habitat contained few, if any animals. The total population was estimated to be 613 (confidence limits=414–967) with an average density of 35·93 km−2 on occupied sites. The population sex ratio was markedly biased towards females (mean=3·4 females to 1 male), but group sizes were similar to those recorded in other African studies. Male groups were on average (2·6), smaller than those of females (7·3). Males appeared to be particularly vulnerable to poaching. The distribution of puku reflected a patchy distribution of resources and a flexible social system. Puku numbers have increased two fold since the previous (1989) survey. Other species have faired less well. Further work is required to clarify dispersal mechanisms. Taylor's power law may provide a useful model for describing population dispersion. Kasanka is an important local refuge for this increasingly threatened species in Zambia. Metapopulation theory may be applicable to puku because of their ability to move between patches, during seasonal flooding. 相似文献
17.
Two male and three female caracal Felis caracal were radio-tracked over a 1-year period in arid shrub on the west coast of South Africa, by day and night over at least 130 days for each caracal, and uninterrupted for up to 120 h at a time. These results, on short-term use of space, were related to concurrent availability of prey. The use by caracal of specific plant communities showed a significant positive correlation to prey biomass of rodents. Males had much larger home-ranges (26.9±0.75 km2 ) than females (7.39±1.68 km2 ). Male home-ranges overlapped completely with those of females, whereas female ranges overlapped between 0 and 19%. Caracal were active by night and day; onset of activity was affected more by ambient temperature (TA ) than photoperiod. Caracal were active significantly longer on nights colder than 20°C. Females ceased activity at TA > 20°C, males at TA > 22°C. Males foraged faster than females (667 vs. 312 m h−1 ) and moved more than twice the distance of females during an active period. Calculated density of caracal was between 0.23 and 0.47 km−2 . 相似文献
18.
Ranges of individual males of three hornbill species were determined by radio telemetry during the breeding and non-breeding seasons in Khao Yai National Park, Thailand. Two Great Hornbills Buceros bicornis and two Brown Hornbills Ptilolaemus tickelli were studied in both 1988 and 1989, and two Wreathed Hornbills Rhyticeros undulatus were studied in 1989, 1990 and 1991.
In the breeding season, the home range of the Great Hornbill was 3.7 km2 , similar to that of the Brown Hornbill (4.3 km2 ), while the Wreathed Hornbill occupied the largest home range (10.0 km2 ). In the non-breeding season, the range size of the Wreathed Hornbill (28.0 km2 ) was greater than that of the Great Hornbill (14.7 km2 ). Differences in range sizes of different species may be related to differences in diet and breeding strategy. Ranges overlapped within and between the species, and this has implications for the estimation of the minimum area required for the conservation of hornbills within the Khao Yai National Park. 相似文献
In the breeding season, the home range of the Great Hornbill was 3.7 km
19.
Despite some populations of European wildcat Felis silvestris in central Europe are stable or increasing, the Iberian subpopulation is in decline and is listed as 'vulnerable'. In Portugal, little is known about wildcat populations, making conservation policies extremely difficult to define. Furthermore, the secretive behaviour of these mammals, along with low population densities, make data collection complicated. Thus, it is crucial to develop efficient analytical tools to interpret existing data for this species. In this study, we determine the home-range size and environmental factors related to wildcat spatial ecology in a Mediterranean ecosystem using a combined analysis of habitat selection and maximum entropy (Maxent) modelling. Simultaneously, we test the feasibility of using radio-tracking locations to construct an ecologically meaningful distribution model. Six wildcats were captured and tracked. The average home-range size (MCP95) was 2.28 km2 for females and 13.71 km2 for one male. The Maxent model built from radio-tracking locations indicated that the abundance of the European rabbit Oryctolagus cuniculus and limited human disturbance were the most important correlates of wildcat presence. Habitat selection analysis revealed that wildcats tend to use scrubland areas significantly more than expected by chance. A mosaic of scrublands and agricultural areas, with a higher proportion of the former, benefits wildcat presence in the study area; however, species distribution is mainly constrained by availability of prey and resting sites. The Maxent model validation with camera-trapping data indicated that highly adequate model performance. This technique may prove useful for recovering small radio-tracking datasets as it provides a new alternative for handling data and maximizing the ecological information on a target population, which can then be used for conservation planning. 相似文献
20.
MARÍA PAULA DELGADO MANUEL B. MORALES JUAN TRABA & ELADIO L. GARCIA DE LA MORENA 《Ibis》2009,151(3):440-451
The Little Bustard Tetrax tetrax is one of the most threatened steppe bird species in Europe, due mainly to agricultural intensification. Despite the relative importance of the Iberian population (approximately 50% of the global population) little is known about its dynamics and trends, especially in core distribution areas. This study evaluates the influences of meteorological factors and land management on the oscillations and medium-term trends of two Little Bustard populations in Central Spain. During 2001–2007, surveys of breeding male and female Little Bustards were carried out in two central Spanish locations: Valdetorres, in Special Protection Area (SPA) no. 139 (1600 ha), and Campo Real, in Important Bird Area (IBA) no. 075 (1150 ha). Densities were 3.3–4.0 and 1.1–2.1 males/km2 in Campo Real, and 1.8–2.2 and 0.6–1.3 females/km2 in Valdetorres. The sex ratio was biased towards males in both cases. Both populations declined during 2001–2007, especially in Valdetorres (60%). Variation in habitat composition did not explain variation in the numbers of males. Both populations were influenced by total precipitation in the preceding October–May period. Results suggest that the Little Bustard may be sensitive to future climate trends in Europe. Finally, different simulated demographic scenarios suggest that low female survival and productivity may be the immediate cause of the decline in Little Bustard populations, which is consistent with their sensitivity to climatic conditions. 相似文献