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1.
Three wild groups of common marmoset, Callithrix jacchus jacchus,in north-east Brazil, of approximately similar size, had home ranges between 2.5 and 6.5 ha. But their core areas were similar in size between 1.0 and 1.5 ha, with a monthly area of heavy use between 1.1 and 1.6 ha. The groups were selective in the use of their home ranges, even though they were small: they used some areas heavily and others lightly. The core areas had higher densities of trees that produced gum exudates than did other parts of the home ranges. Our data suggest that a group of marmosets in this habitat may require a minimum of about 50 gum trees in its home range at a minimum density of about 50 trees/ha. In addition, the animals require suitable trees in which to sleep. We suggest that patches of forest with these desirable properties remain relatively fixed in size and location over the years and that individual animals are constantly in flux between them.  相似文献   

2.
In this paper I examine exploratory behavior and learning in two groups of common marmosets (Callithrix jacchus jacchus), both living under laboratory conditions. The main aim of my studies was to compare behavior occurring in an experimental testing situation with home-cage behavior, and to assess conditions under which exploration is enhanced. One group of marmosets was tested individually in an experimental room away from a larger animal holding room, and a second group was observed in their own home cages, surrounded by other marmosets. Marmosets in both groups were given the opportunity to learn simple tasks, such as pressing a lever for food or jumping on to a wire grid to open a door and see a neighbouring marmoset, and were provided with sets of novel or familiar objects to encourage play and exploration. In the isolated experimental cage, marmosets which learnt a lever-pressing task showed higher general activity levels than controls; in the home cages the mere addition of novel objects resulted in enhancements in exploratory behavior (measured in terms of contacts with the objects). Although the activities associated with learning tended to decline over time, the novel objects remained a constant interest throughout the experiment. The results have implications for maintaining marmosets in captivity, especially in situations when they are housed separately.  相似文献   

3.
Agonistic behavior was observed in five captive groups of the monogamous monkey Callithrix jacchus jacchus,which normally produces twin offspring every 5 months. Fighting is first recorded when twins are aged 5–10 months. These “twin fights” determine differences in status between combatants that can be detected 5 months later. From what is known of the social behavior of the species, it is postulated that an individual’s twin is its most serious rival and that early fighting is advantageous because injury is minimal while the animal retains its milk dentition. In contrast to twin fights, aggression between same-sex juveniles and adults does not involve long fights and probably serves to reinforce preexisting differences in status. It often results in forcing a group member to the periphery, and therefore, its main function may be to drive mature, same-sexed individuals out of the group. Apart from the relationship between twins, status within the family group is age related and not normally determined by aggression.  相似文献   

4.
The behavioural repertoire of four captive breeding pairs of Callithrix jacchus jacchus is described. Social communication took the form of postures, facial expressions, vocalizations and piloerection displays. Detailed analyses were made of piloerection displays, adult play, copulatory, aggressive, and prey-catching behaviour. Aggressive behaviour was uncommon in adult mated pairs. Play between adults showed a degree of temporal organization. Vocalizations were the main methods of intragroup communication whilst piloerection displays were directed towards members of other groups and also to unfamiliar objects. The behavioural repertoire of C. jacchus jacchus is compared with that of other Primates.  相似文献   

5.
Callithrix and Leontopithecus exhibit ecological differences that have implications for the patterns of infant care. In C. jacchus, which uses a small home range because it depends mainly on plant exudates, infants can forage independently early in their life. L. chrysomelas, which feeds mainly on fruits and insects, needs larger home ranges and, therefore, its infants have a more extensive period of dependence. Three families of C. jacchus and four families of L. chrysomelas were studied in captivity. The animals were observed starting from the birth of the infants up to their 8th week of age. Our results suggest that the pattern of infant transfer in L. chrysomelas did not follow the one reported for L. rosalia in that transfers from the mother occurred much earlier. L. chrysomelas infants were carried for about 15% of total time during the 8th week of life against less than 1% in C. jacchus in the same week. Infant care seems to be more extensive in L. chrysomelas than in C. jacchus, and the period of exclusive mother carrying in L. chrysomelas is shorter than that observed in L. rosalia.  相似文献   

6.
A five and a half month field study on the common marmosetCallithrix jacchus jacchus, was carried out during the dry season at Tapacura near Recife, Brazil. Twelve groups were counted and group sizes ranged between 3 and 13 animals. The age/sex class composition of three groups was determined by observation of one group and by trapping two others. Five groups were counted over a period of five months and one group over four months, during which two confirmed cases of immigration into groups were observed. The evidence for birth seasonality is considered. Data are presented to support the hypothesis that there is only one breeding female per group, although a group containing two mature females was observed. The observations are compared with those obtained for other Callitrichid species.  相似文献   

7.

Red foxVulpes vulpes (Linnaeus, 1758) are generally regarded as strictly territorial animals, inhabiting distinct and well-separated ranges. The home ranges of these predators can vary in size from a few dozen hectares to as much as 20–30 km2. Because it seemed impossible that foxes could defend areas so different in size with the same intensity, the published data were analysed in order to see how changes in home range size could affect the following parameters: home range overlap, the area visited daily and the distance travelled by animals during 24 h. It was found that the overlap between fox families (groups) occupying large ranges was much greater than between foxes living in small ranges. The ratio of the area visited daily to the seasonal home range size was greater in small ranges than in large ones. No significant correlation was found between the mean distance moved daily and home range size (r = −0.118,p = 0.75). These results suggest different patterns of the use of space and differences in territorial defence by red foxes inhabiting large and small ranges. The implications of home range overlap and intensity of contacts between foxes occupying neighbouring ranges for the spread of disease are discussed. The significant overlap between large ranges found in this paper is discussed in the light of Andrzejewski’s (2002) home range concept.

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8.
Five groups ofCallithrix jacchus jacchus were studied in the field in north east Brazil. Group size and composition were similar to that described for other callitrichids, but changes in group membership occurred much more frequently than previously reported. There was a 50% turnover in group membership in a six month period, and adult males changed groups particularly often. Most groups contained only one reproductively active female, but there was evidence that one group contained two females that were reproductively active simultaneously. Some groups had several adult females, and the role of reproductive female switched from one individual to another with time. Individual marmosets are faced with an unusually wide range of alternative life history strategies involving different combinations of location and reproductive condition. We argue that marmoset social organization is best studied at the level of the whole population within an area, rather than at the level of the individual group.  相似文献   

9.
Callitrichids have been proposed as communal breeders, with non-reproductive animals acting as helpers. Reports in the literature attest to the high variability in the behaviour of helpers. The present study assessed four proximate factors involved in helping in captive Callithrix jacchus: age, gender and experience of helpers and composition of their groups. Forty-eight helpers from 15 families from Natal (Brazil) and Reading (UK) colonies were observed during the first 4 weeks of life of new-born twins. Infant carrying, transfers and retrieval, and duration of carrying bouts were registered. Results showed that the presence of helpers decreased the costs of infant carrying, with a negatively significant correlation between group size and mean percentage of carrying. Age, but not gender, was a significant factor for infant carrying, transfers and retrieval, and mean duration of carrying bouts, with older helpers contributing more than younger ones. Singletons and oldest non-reproductive offspring carried infants more, and longer, than twins and offspring with older siblings present in the group. Experience decreased motivation and actual carrying time, but not to a significant level. Age, experience and group composition appeared important factors in the display of infant care by helpers in captive Callithrix jacchus.  相似文献   

10.
The effects of intensive commercial livestock farming on the distribution and habitat use of the redwing francolin, Francolinus levaillantii, was investigated to identify habitat constraints that may contribute towards the observed decline of this species on livestock farms. Data on the size, placement of the home ranges and compositional habitat use from ten radio‐tracked individuals, five in commercially grazed (and frequently burned) and five in protected (and infrequently burned) highland grasslands, was collated to determine habitat preferences. Mean home range size within protected and grazed grassland study sites were similar and ranged between 7.6 and 15.4 hectares. However, habitat use by groups in grazed grasslands was restricted to areas of greater cover and food availability. Group sizes were significantly larger in protected (mean 3.77, n = 111 coveys) than in grazed and frequently burned grassland (mean = 2.96, n = 135 coveys). Smaller coveys in grazed habitats had smaller home ranges and were further spaced from one another. It is therefore suggested that habitat degradation, through excessive defoliation of the grassland from heavy grazing and frequent burning, both fragments francolin subpopulations and reduces the ecological availability of suitable habitat. Thus, undermining the metapopulation structure of the redwing francolin in these commercially grazed grasslands.  相似文献   

11.
Space use by the Japanese fluvial sculpin, Cottus pollux, as related to nest availability was studied in a Japanese mountain stream. Males had larger home ranges than females before breeding. A measure of nest resource limitation was L < 1 and the same nest rock was used by two males successively in three cases, indicating a limited supply of suitable nest rocks for males. All males included the nest rocks in their home ranges, but the timing of nest occupation was apparently dependent on male size, suggesting the presence of male-male competition for the nest rocks. Females, on the other hand, exhibited two different patterns in space use, independent of body size: (1) they spawned in their home ranges, or (2) they spawned out of their home ranges and returned. Nest cavity area did not affect male reproductive success. Spatial separation between female home ranges and nest location was the main reason for the females' movement out of their home ranges. The limitation in the male mating phase (5.7 days on average) might also have forced the females to move out of their home range to spawn. The reason behind such temporal limitation in the male mating interval was discussed from the viewpoint of the energy cost accompanying male parental care.  相似文献   

12.
The social organization of Galago garnettii was studied for the first time and the study included data from two different sites in the coastal forests of Kenya. A combination of mark-recapture and radio-tracking techniques was used to investigate patterns of inter- and intrasexual home range overlap. Patterns of range use were established by radio tracking focal individuals. Adult females of different ages shared highly overlapping ranges, while like-aged females showed little range overlap. Females matured and had their first infants in their natal ranges. Adult males' ranges were larger than those of females and overlapped them extensively. Resident adult males showed little range overlap with each other, unless they were of different ages. Turnover of males was frequent in both populations. Males probably dispersed from their natal ranges. Adults rarely slept together. The social organization of G. garnettii is relatively similar to that of the closely related G. crassicaudatus of southern Africa but contrasts with that of its sympatric congener, G. zanzibaricus. The differences and similarities between these three species are discussed in relation to diet and body size.  相似文献   

13.
Mountain gorillas are highly folivorous. Food is abundant and perennially available in much of their habitat. Still, limited research has shown that single gorilla groups heavily used areas where food biomass and quality were relatively high and where they met daily nutritional needs with relatively low foraging effort. Also, ecological factors influenced solitary males less than groups with females. Long-term data on habitat use by multiple mountain gorilla social units and more extensive data on variation in food distribution, presented here, confirm that food distribution influences areal occupation densities across groups and over time. These data also confirm the group/solitary male distinction and show that food distribution became more important for one male once he acquired females. Groups used 25 km 2 , and inter-annual home range and core area overlap was often low. Annual home range and core area size varied considerably within groups and across years. It bore no simple relationship to group size and estimated group biomass. Core areas were biased samples of total home ranges and were relatively good foraging areas. One group abruptly shifted its home range in response to male mating competition. Home ranges of two others expanded from 1981 to 1987, though at a decreasing rate. Data on one such group, which varied considerably in size, are consistent with arguments that costs of scramble competition are low except in unusually large groups. Low site fidelity, low scramble costs, and high home range overlap should decrease the ecological costs of female transfer.  相似文献   

14.
Summary Home ranges of the Galapagos land iguana (Conolophus pallidus) were examined with respect to food availability and the thermal environment. Activity patterns, the amount of space used per day, and time required to use the entire home range were also investigated. The effects of, and the relationships between, these factors vary seasonally, as do home range sizes and preferred body temperatures.Food supplementation experiments resulted in only temporary reductions in use of space. Home range sizes were not different between the seasons with the least (Fall) and the most (Hot) food availalble, but home ranges were significantly smaller in Garua when food supplies were low, but not as low as in Fall. Calculations of metabolic expenditures in each season suggests that food availability alone does not explain seasonal patterns of home range size in this species.The thermal environment within each home range was characterized by microclimatic measurements and measurements of the area of sun, shade, and semi-shade. An index with units of m2h was used to quantify the thermal quality of each home range. Iguanas exploited optimal (with respect to body temperature) conditions more than would be expected from random use of their home ranges. Thermal transients (due to large body size) and optimal conditions were exploited to the largest degree in Fall.During Garua, low metabolic rates and time constraints imposed by an abundance of stressful thermal environments may result in small home ranges. In Fall, increased temperatures cause higher metabolic rates and allow more time for exploitation of the cooler portions of the home range, hence, home range sizes increase. In the Hot season, there is abundant food and optimal thermal conditions, but home ranges remain large. Searching for preferred foods may cause the large home ranges in this season.  相似文献   

15.
《Ostrich》2013,84(3-4):186-194
There The Wattled Crane Bugeranus carunculatus is one of the top five most threatened bird species in South Africa, with the main threat being the loss of undisturbed breeding habitat. A basic understanding of this species' use of its environment is needed to implement conservation action. This quantitative study focused on determining the home range size of active breeding pairs in the KwaZulu-Natal midlands of South Africa, and assessing the land use composition of these home ranges. Wattled Cranes were found to have an average home range size of 16.64km2, consisting mostly of open natural grassland (mean of 75.5% of the overall home range of pairs). Other significant land use contributions to the home ranges were temporary irrigated and dryland cultivated agriculture. The core breeding area (wetland) of the home range constituted only 2.3% of the overall home range size, consisting of similar proportions of both wetland (48.9%) and grassland (51.8%) habitat. This indicates the dependence of Wattled Cranes on specific wetland habitats, surrounded by natural grassland. Wattled Cranes show home range sizes larger than other similar-sized crane species, suggesting that this may be as a result of their large body size and their occupation of highly transformed and fragmented habitats in an agricultural landscape. However, the occurrence of transformed land use types in home ranges suggests that breeding pairs tolerate some degree of disturbance within their home ranges. The home ranges do not appear to be currently restricted by surrounding land use types, indicating that factors other than habitat loss may be contributing to breeding site losses. The study has therefore indicated the need for closer working relationships between conservationists and agricultural communities to promote the conservation of valuable natural grasslands surrounding wetlands.  相似文献   

16.
We analysed the home ranges of a community of Darevskia rock lizards composed of a bisexual species (D. valentini), two parthenogens (D. armeniaca and D. unisexualis), and two backcross forms between bisexual and unisexual forms. We estimated home range areas of ink-marked, GPS-located lizards using Minimum Convex Polygon (MCP) and 95% of the locations for those individuals with five or more sightings. The bisexual D. valentini was the species with the largest home ranges, distances travelled, and the most intersections. No differences between unisexual species and backcrosses were recorded for any comparison. In males, home range size and perimeter were related to morphological characteristics. Contrary to what has been described in allopatry, unisexual species showed smaller home ranges and fewer overlaps than sympatric bisexual species. We tentatively suggest that the presence of potential bisexual partners might increase sexual competition among parthenogenetic females while differences in habitat use should also be considered.  相似文献   

17.
The social organization of Galago zanzibaricus was studied for the first time and the study included data from two different sites in the coastal forests of Kenya. A combination of mark-recapture and radio-tracking techniques was used to investigate patterns of inter- and intrasexual home range overlap. Associations in sleeping groups indicated social ties between individuals. Patterns of range use were established by radio-tracking focal individuals. Adult males generally had nonoverlapping ranges, shared with one or two females and their offspring with which the male regularly slept. Young females remained longer in their natal ranges than males and reproduced within their natal ranges. Range size and distance traveled per night were similar between the sexes; both sexes probably defended territories. None of the other galago (bushbaby) species studied to date show the degree of close male-female association found in G. zanzibaricus. This study thus extends the variety of social organization documented in nocturnal prosimians.  相似文献   

18.
The Aransas-Wood Buffalo population (the only non-reintroduced, migratory population) of endangered whooping cranes (Grus americana) overwinters along the Texas Gulf Coast, USA. Understanding whooping crane space use on the wintering grounds reveals essential aspects of this species' ecology, which subsequently assists with conservation. Using global positioning system telemetry data from marked whooping cranes during 2009–2017, we fit continuous-time stochastic process models to describe movement and home range using autocorrelated kernel density estimation (AKDE) and explored variation in home range size in relation to age, sex, reproductive status, and drought conditions. We used the Bhattacharyya coefficient of overlap and distance between home range centroids to quantify site fidelity. We examined the effects of time between winter home ranges and the sex of the crane on site fidelity using Bayesian mixed-effects beta regression. Winter whooping crane 95% AKDE home range size averaged 30.1 ± 45.2 (SD) km2 (median = 14.3, range = 1.1–308.6). Home ranges of sub-adult females were approximately 2 times larger than those of sub-adult males or families. As drought worsened, home ranges typically expanded. Between consecutive years, the home ranges of an adult crane exhibited 68 ± 31% overlap (site fidelity), but fidelity to winter sites declined in subsequent winters. The overlap of adult home ranges with the nearest unrelated family averaged 33 ± 28%. As a whooping crane aged, overlap with its winter home range as a juvenile declined, regardless of sex. By 4 years of age, a whooping crane had approximately 14 ± 28% overlap with its juvenile winter home range. Limited evidence suggested male whooping cranes return to within 2 km of their juvenile home range by their fifth winter. Previous data obtained from aerial surveys led ecologists to assume that whooping crane families normally used small areas (~2 km2) and expressed persistent site fidelity. Our analyses showed <8% of families had home ranges ≤2 km2, with the average area 15 times greater, and waning site fidelity over time. Our work represents an analysis of whooping crane home ranges for this population, identifying past misconceptions of winter space use and resulting in better estimates of space requirements for future conservation efforts.  相似文献   

19.
The home range ofTakydromus tachydromoides was studied in a grassland area from April 1977 to November 1978. The mean size of home range did not differ markedly between sexes; 136.5 m2 for males and 130.8 m2 for females. Home ranges of adults overlapped greatly in each sex, and the lizard was considered to be non-territorial. Individuals showed return movement to a definite area (sleeping site) within the home range, and the home range did not shift within a year or between years. Characteristics of the home range of this grassland-inhabiting lizard were discussed in relation to resource abundance and predation pressure.  相似文献   

20.
Animals that rely on refuges for safety can theoretically increase their foraging area without simultaneously increasing predation risk and travel costs by using more refuges. The key prediction of this theory, a negative correlation between food abundance, home range size and the number of refuges used, has never been empirically tested. We determined how home range size and refuge use by the Central American agouti (Dasyprocta punctata) varied across a gradient of abundance of the agoutis' principal food source: seeds and fruits of the palm Astrocaryum standleyanum. We used both manual and automated radio telemetry to measure space use of 11 agoutis during 2 mo of the Astrocaryum fruiting season, and of another set of 10 agoutis during 6 mo in which the animals largely relied on cached Astrocaryum seeds. We found that agoutis living in areas of lower food density had larger home ranges, and that all individuals used multiple refuges. The number of refuges, however, was not correlated with home range size. Consequently, agoutis that had larger home ranges roamed farther from their refuges. These results suggest that agoutis increase their home range size in response to food scarcity at the cost of their safety.  相似文献   

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