首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The recently discoveredCallithrix humeralifer intermedius occurs between the Rios Roosevelt and Aripuanã in Brazil. This paper presents some preliminary observations ofC. h. intermedius in the wild from May to November 1978. They occupy dense primary forest, second growth and low white sand forest. Group size is between 4 and 13, the larger groups comprised of more than one adult pair. One group, watched for 160.5 hr, occupied a home range of 13.75 ha, during this period, travelling between 740 and 1,500 m during the day. Principal foods include small fruits, flowers, tree exudates and insects. Groups were observed with one pair of newborn infants during September and October, at the end of the dry season. Observations of social behaviour (including agonistic behaviour, grooming, tail coiling behaviour and scent marking), development of young, vocalizations and potential predators are described.  相似文献   

2.
Data were obtained both from observation and by radiolocation on the size and use of the home range of the common marmoset, Callithrix jacchus jacchus.Ranges were small compared to those of other callitrichids, varying between 0.72 to 1.62 ha, and a high proportion of the home range was used each day. The marmosets showed territorial behavior, defending an area almost equivalent to the home range. Despite this, mating between animals belonging to neighboring groups was seen. Correlations between the use of the home range and some environmental variables showed little consistency between two groups which occupied ranges of differing resource density, and their activity patterns, as measured by movement through their ranges, were also different. Possible reasons for these inconsistencies are discussed.  相似文献   

3.
The ranging behaviour of a group of marmosets ( Callithrix humeralifer ) in seasonal Amazonian rain forest was studied during one year. Range sizes (monthly and daily), day range lengths and patterns of range use are examined for correlations with feeding behaviour and the distribution of three forest types within the marmoset's range. Seasonal differences in ranging are associated with changes in the abundance and distribution of plant food sources. The marmosets ranged more widely and used more sources of a greater diversity of plant food species, which were distributed over a wider area, in the wet season than in the dry season. In the dry season, they ranged over a smaller area and, although they used fewer sources of a reduced diversity of plant species overall, they exploited a larger number of sources of the five highest ranked plant species in the diet. Throughout the year, they showed a preference for disturbed primary forest, characterized by dense understoreys and abundant second growth patches. Reasons for this preference are discussed, taking into account their use of fruits of typical pioneer species (particularly in the dry season), insect prey abundance, sleeping site availability and defence against predators.  相似文献   

4.
Tamarin activity patterns and habitat utilization strategies in the Tropical Dry Forest of the Panama Canal Zone were monitored quantitatively using radio-location telemetry. The daily tamarin activity pattern differed from that of other Neotropical primates in that early morning and late afternoon activity normally did not occur. Total daily activity time averaged 676 +/- 62 min. Sleeping trees, and behaviors associated with their use, were documented. Daily path length averaged 2,061 +/- 402 m. Mean travel distance was 468 +/- 66 m. Approximately one-third of the home range was utilized on a given day. Wet season home ranges for two social groups were 26 and 32 ha in area. Areas of low brush, forest edge, and vine-entangled second growth were heavily used by foraging tamarins. Large shade trees, particularly evergreens, were important as refuges from solar radiation. Open-canopy forest types and areas of grass were avoided. Social groups on resource-stable lowland sites defended territories; those on unstable upland sites used a system of time-space segregation. Upland groups became seminomadic during the dry season. Suitability of home range site may affect social group stability, natality, and infant survivorship.  相似文献   

5.
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   

6.
Spatial and temporal habitat use of kob antelopes (Kobus kob kob) have been investigated in the Comoé National Park (Ivory Coast, West Africa) by use of radio telemetry. A total of 23 kob were equipped with radio collars and radio tracked for up to 15 months. Home ranges of males were smaller and those of females larger than expected from theoretical models. Adult males used smaller areas than adult females and did not show seasonal home range shifts. Daily distances travelled did not differ between sexes. Kob walked less during the night than by day and covered shorter distances in the wet season. Whereas an increase in home range overlap between females resulted in higher rates of association among individuals, association of adults of mixed sexes was not correlated with the degree of home range overlap. Territorial behaviour of males and predator avoidance by females are suggested to explain the sex‐specific differences in home range size of adults and the deviation from the predicted sizes. Predator avoidance is presumed as the main reason for the reduced walking distances at night as well as in the wet season. Reproductive behaviour and feeding ecology are assumed to determine the degree of association of conspecifics.  相似文献   

7.
During a 14-month study of one group of woolly spider monkeys, or muriquis (Brachyteles arachnoides),at Fazenda Montes Claros, M. G., Brazil, the group used a home range of 168 ha. Day-range lengths averaged 1283 m and were longer in the wet season than in the dry season. An analysis of travel rates indicated that the group traveled faster on those days when they traveled farther. The availability of large patches of preferred food sources appears to affect daily movement patterns. Intraspecific comparisons, in addition to an apparent expansion of the study group’s home range as their group size has increased, suggest the importance of group size to muriqui range size. Interspecific comparisons between muriquis and sympatric brown howler monkeys suggest that locomotor adaptations are important to understanding species differences in ranging behavior.  相似文献   

8.
The control of feral goats (Capra hircus) was studied on Aldabra Atoll, Republic of Seychelles, from October 1993 to May 1994 and November 1994 to May 1995. A total of 832 goats was killed on Aldabra using the Judas goat technique and traditional hunting methods. Twenty-eight goats equipped with radio transmitters (Judas goats) were used to locate and kill other feral goats. The remnant goat populations on Ile Picard (n=13) and Ile Malabar (n=19) were eradicated during the first season. On Grande Terre, a total of 798 (374 M : 424 F) goats were killed. Mean group size was 3.2 with a range of 1–20. Judas goat hunting became increasingly important over time with 18.0% (n=85) of goats killed in the presence of Judas goats in the first season compared to 42.3% (n=126) of goats killed during the second season. The overall kill rate for the project was almost 2 times greater for Judas goat hunting (0.61 goats killed/h) than traditional hunting (0.32 goats killed/h). The home range size of each Judas goat and the number of goats killed in association with it was significantly related. Using the Leslie–Davis removal method of population estimation, 84 goats were estimated to remain on all of Grande Terre at the end of thebreak project. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
Ranging behavior is an important aspect of animal behavior that researchers use to investigate ecological influences on individual behavior. We studied the influence of diet, water resources, and sleeping sites on the ranging behavior of 2 groups of white-headed langurs (Trachypithecus leucocephalus) in a limestone habitat at Fusui Nature Reserve, China, between August 2007 and July 2008. During the study period, the total home range sizes for the 2 focal groups were 23.8 ha and 33.8 ha, the mean daily path lengths were 491 m and 512 m, and leaves accounted for 83.4% and 91.0% of the diet, which are well within the range of variation reported for other Trachypithecus. One focal group traveled significantly longer distances in the rainy season months than in the dry season months. This variation may be related to the seasonal difference in food availability and diet. The langurs did not use their home ranges uniformly, and 50% of their activities occurred within 11% (group 1) and 20% (group 2) of their home ranges. The most heavily used quadrats in the home ranges were located near the most frequently used sleeping sites. Moreover, the core areas (>70% of location records) of both groups’ home ranges included ≥1 permanent water pool. The langurs ventured to these pools for drinking when surface water became scarce in the dry season. These results suggest that sleeping sites and water scarcity may be significant influences on the ranging behavior of white-headed langurs in limestone habitat.  相似文献   

10.
Twenty Hoplias aimara were tagged intraperitoneally with radio-transmitters in the Sinnamary River, French Guyana. In November 1993, 13 tagged fish were released in an area which would be flooded by the Petit-Saut reservoir impoundment in mid-1994. Seven other tagged fish were released in January 1994, 20 km upstream of the upper limit of the reservoir. Hoplias aimara showed site fidelity: 75% of fish returned to their capture site before the test area was inundated. The remaining fish stayed close to the release area. Monitoring during three 24-h cycles before reservoir filling showed that H. aimara has a limited home range, which is less marked in unconstrained reaches during the wet season (April to August) than in constrained reaches during the dry season (September to November). In natural conditions, H. aimara has a wider home range in unconstrained river reaches than in constrained river reaches. After closure of the dam, in September and October 1994 (dry season, low water) more than half of the total H. aimara tagged in the flooded zone migrated upstream following the rise of water.  相似文献   

11.
罗布泊野骆驼的家域特征及其意义   总被引:1,自引:0,他引:1  
野双峰骆驼(Camelus ferus)生活在荒漠戈壁, 种群数量稀少, 栖息地地形复杂多样, 且有长距离迁徙习性, 目前对其家域面积和重要栖息地范围的研究只有定性描述。本研究于2012年5月至2013年7月, 在阿奇克谷地和阿尔金山北麓捕捉了8峰野骆驼并安装GPS卫星跟踪项圈, 分别获得了12-423天的13,748个GPS位点记录。研究结果表明, 8峰野骆驼的100%最小凸多边形(minimum convex polygons, MCP)家域面积分别为1,775-11,768 km2, 总家域面积为32,821 km2, 占罗布泊野骆驼分布区面积的23.1%, 平均家域面积为7,349 ± 1,323 km2。野骆驼个体家域面积季节间差异显著, 秋季最大, 其次是冬季和夏季, 春季最小, 秋季是春季的4.4倍。野骆驼在繁殖季节的家域平均面积为879 ± 320 km2, 非繁殖季节为998 ± 106 km2, 二者间无显著差异。除了项圈编码为135号的野骆驼和其他7峰野骆驼的家域没有重叠外, 其余7峰野骆驼的家域都有重叠。这7峰野骆驼的家域总面积是24,910 km2, 占罗布泊野骆驼分布区总面积的17.5%, 重叠区面积是515 km2。鉴于野骆驼主要分布在阿奇克谷地及以南区域、阿尔金山北麓, 建议将罗布泊野骆驼国家级自然保护区位于阿奇克谷地北山以北的核心区部分区域、磁海低地以南的山区和阿尔金山西部原为实验区的部分区域调整为缓冲区, 而将阿尔金山北麓至库姆塔格沙漠之间的戈壁地带原为缓冲区的部分区域调整为核心区。  相似文献   

12.
Data on activity budgets and ranging patterns were collected from March to December 2001 for one group of François’ langurs (Trachypithecus francoisi) inhabiting a forested part of the Fusui Nature Reserve, Guangxi province, China. Our results indicate that the total size of the home range of the study group during the study period was 19 ha. The majority of their activities (52%) occurred within a small area, 22%, of their home range, and was concentrated in or near quadrats containing their sleeping sites, which may reduce the time and energetic cost of travel. The extent of the ranging behavior varied between months, with the smallest, 7 ha, recorded in July and the largest, 13.5 ha, in November. There was no significant difference between seasons. The monthly mean daily path lengths varied from 341 to 577 m. The daily path lengths showed significant seasonal changes: the path lengths were longer during the dry season than in the rainy season, which may be related to the scarcity of preferred food resources during the dry season.  相似文献   

13.
We have analyzed the ranging patterns of the Mimikire group (M group) of chimpanzees in the Mahale Mountains National Park, Tanzania. During 16 years, the chimpanzees moved over a total area of 25.2 or 27.4 km2, as estimated by the grid-cell or minimum convex polygon (MCP) methods, respectively. Annually, the M group used an average of 18.4 km2, or approximately 70 %, of the total home-range area. The chimpanzees had used 80 % of their total home range after 5 years and 95 % after 11 years. M group chimpanzees were observed more than half of the time in areas that composed only 15 % of their total home range. Thus, they typically moved over limited areas, visiting other parts of their range only occasionally. On average, the chimpanzees used 7.6 km2 (in MCP) per month. Mean monthly range size was smallest at the end of the rainy season and largest at the end of the dry season, but there was much variability from year to year. The chimpanzees used many of the same areas every year when Saba comorensis fruits were abundant between August and January. In contrast, the chimpanzees used several different areas of their range in June. Here range overlap between years was relatively small. Over the 16 years of the study we found that the M group reduced their use of the northern part of their range and increased their frequency of visits to the eastern mountainous side of their home range. Changes in home-range size correlated positively with the number of adult females but not with the number of adult males. This finding does not support a prediction of the male-defended territory model proposed for some East African chimpanzee unit-groups.  相似文献   

14.
A study of the airborne pollen grains in Nsukka, Nigeria, has been carried out at two different sampling heights (1.8?m and 15?m) from February 1993 to January 1994. Twenty‐six plant families (40 genera) were identified at the lower sampling height, whilst thirty‐eight families (58 genera) were identified at the height of 15?m. A total of nine and eighteen fern spore types were observed at 1.80?m and 15?m, respectively. The quantitative results indicate that the number of pollen observed at 15?m sampling height was statistically different (p<0.05) from that observed at the height of 1.80?m. The analysis of airborne pollen grains indicates three different periods: (1) dry season, (2) rainy season, and (3) late rainy season to early dry season/Harmattan. The highest pollen abundance was recorded during the late rainy season – early dry season/Harmattan followed by that of the dry season. The predominant pollen grains and fern spores trapped at both heights include Poaceae, Casuarina equisetifolia, Milicia excelsa, Elaeis guineensis, Celtis integrifolia, Alchornea cordifolia, Amaranthaceae/Chenopodiaceae, Combretaceae/Melastomataceae, Nephrolepis biserrata, Thelypteris totta, and Dryopteris spp.  相似文献   

15.
We collected systematic data on the home range and day ranges of one group of 57–63 muriquis (Brachyteles arachnoides hypoxanthus) at the Estação Biológica de Caratinga, Minas Gerais, Brazil from September 1998–July 1999, and compared them with similar data collected 15 years ago when the 23–27 individuals in the group traveled together as a cohesive unit. Home range size increased from 168 ha to 309 ha, reflecting an expansion into areas of the forest that were previously unutilized and consistent with the positive relationship predicted between group size and home range size. By contrast, muriquis exhibited remarkable seasonal and interannual stability in their day ranges. Day ranges, which were calculated from 144 days with 8 h of observation, averaged 1,313 ± 573 m (median = 1,206 m). Day ranges did not vary with the size of subgroups, defined as independent individuals that traveled with one another out of contact with other group members. Subgroups were significantly larger during the rainy season (mean = 41.8 ± 12.7, median = 46.0 individuals, n = 72) than the dry season (mean = 36.6 ± 13.25, median = 39.5 individuals, n = 72). Subgroups were also larger than the size of the entire group during the previous study, yet their day ranges are indistinguishable. The stability in muriqui day ranges is consistent with predictions for folivorous primates in which other indicators of intragroup feeding competition, such as female dominance relationships, are also absent. We attribute the transition from cohesive to fluid grouping patterns to limits on the number of individuals that can coordinate their movements when they spread out while foraging and suggest that seasonal differences in subgroup sizes without corresponding adjustments in day ranges reflect seasonal differences in the distribution of preferred foods coupled with the effects of reproductive seasonality on muriqui grouping patterns.  相似文献   

16.
We studied factors affecting variation in home-range size of four groups of bare-ear marmosets (Callithrix argentata) in patches of forest within a central Amazonian savanna. We determined relative use of different parts of the home range by radiotelemetry. We estimated fruit availability monthly in transects through each home range and mapped the habitats within the home range of each group. We determined the densities of gum- and fruit-producing trees in 18 50 × 50-m quadrats and related these data to the frequency of use by marmosets. Home-range size varied by a factor of 6 between groups, even though the study area covered <15 km 2 and included only one major biome. Marmoset activity was concentrated in areas with many gum-producing trees. Monthly range size is positively correlated with fruit availability only for the group with the largest home range; the other groups appeared to be responding to other factors. Home-range sizes appeared to be limited by the size of the main patch of contiguous forest available to each group. Our findings suggest that conservation planning that does not consider the possibility of large differences among primate home-range sizes may be unsatisfactory.  相似文献   

17.
Field observations of black Sigatoka disease symptom development were made on banana plants from four sites (30 m apart) within an unsprayed plantation of dimensions 100 m × 200 m in Costa Rica during two field visits: October 1993-February 1994 (wet to dry season) and April-September 1995 (dry to wet season). From these observations, estimates of the symptom-free period and the average rate of symptom development (during the symptomatic phase) were made for each leaf. No significant differences were found between sites in rates of symptom development in either 1993/94 or 1995, or in symptom-free period for 1993/94 (data were not suitable to test for between-site differences in symptom-free period for 1995). This suggests that forecasts would not have to take into account differences in location within this small plantation. Symptom-free time decreased over the 1995 observation period, was less than in 1993/94 and correlated with increases in hours per day at a relative humidity (r.h.) of 100%. Because plantations may be sprayed many times per year, forecasts have to be sensitive to short-term changes in disease severity. Seasonal trends in some more rapidly-and easily-assessed characters (number of disease-free leaves, disease scores of specific leaves and average disease scores of entire plants) accurately reflected trends in the more detailed observations of symptom severity, hours per day at 100% r.h. and numbers of leaves unfurling per unit time. This suggests that these could be used as indicators of changes in disease severity in a forecasting scheme.  相似文献   

18.
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   

19.
Is Atlantic salmon production limited by number of territories?   总被引:1,自引:0,他引:1  
Thirty Atlantic salmon Salmo salar parr (mean 135 mm total length, L T) in the River Alta, Norway, were radio‐tagged and tracked during a 11–13 day period. The parr stayed within defined home ranges with a 95% probability of localization within an average area of 1286 m2(241–3484 m2). On average, each parr had overlapping home ranges with 7·7 other parr, and the overlap between pairs of fish covered on average 24% of their home range areas. Mean length of the river stretch used was 90 m (22–383 m). On average, during 38%(16–77%) of the tracking surveys, the fish had moved >10 m since the previous survey. Mean total distance moved during the whole study was 402 m (208–862 m). The Atlantic salmon were most often recorded in riffles, but 27% of the parr alternated between riffles and pools. The extensive movements, flexible habitat utilization and relatively large home ranges, together with the fact that all the parr had home ranges partly overlapping with other radio‐tagged parr, indicate a flexible and variable behaviour and, thereby, a more complex social structure than a rigid defence of a fixed territory. Thus, Atlantic salmon production seems not to be limited by the highest potential number of territories for large parr in a given area.  相似文献   

20.
1. Energy requirements explain substantial variation in movement and home range size among birds and mammals. This study assesses whether the same is true of snakes by comparing ratsnakes (Elaphe obsoleta) and racers (Coluber constrictor), ecologically similar species whose energy requirements appear to differ substantially (racers > ratsnakes). 2. Over 4 years 22 Elaphe and 16 Coluber were radio-tracked at the same site in Illinois to examine how movement and home ranges varied by sex and season. 3. Coluber moved more often and further per move than Elaphe, resulting in their estimated mean day range being almost four times larger than that of Elaphe (88.0 m day(-1) vs. 23.1 m day(-1)). 4. Both male and female Elaphe moved more frequently early in the season consistent with mate-searching, but mean distances moved did not differ seasonally or by sex. Both sexes of Coluber moved more later in the season and overall males moved further than females. 5. Interspecifically, patterns were consistent with the energetics hypothesis--Coluber had mean home ranges approximately four times larger than those of Elaphe. 6. Intraspecifically, increased movement did not always produce larger home ranges. Male Elaphe had larger home ranges than females despite not moving further, whereas male Coluber had comparable home ranges to females despite moving further. Also, Elaphe home ranges in Illinois were substantially smaller than has been documented in Ontario, despite Ontario Elaphe moving less. 7. Our results generally support the energetics hypothesis, but indicate that knowledge of ecology and energetics increases our understanding of area requirements beyond simple allometric predictions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号