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1.
A population of rhesus macaques in the Taihang mountains on the Henan-Shanxi border is probably the northernmost population of the species. A more northerly population north of Beijing was locally extirpated in 1988. In the Taihang mountains, 26 natural groups, with >2000 monkeys, have been found. Six of them have been studied for 8 years. They live in a deciduous forest with temperate climate and cold snowy winters. The average group size is 82 individuals, and the population density is 3.1–7.2 individuals per km2. Home rangs are very large, varying from 11 to 22 km2. A natural reserve for the rhesus was established at Jiyuan in 1982, and one group, monitored and provisioned since 1984, has increased from 47 to 83 individuals, an increase of 76.5%.  相似文献   

2.
C. J. BROWN 《Ostrich》2013,84(1-2):43-49
Brown, C. J. 1990. Breeding biology of the Bearded Vulture in southern Africa, Part III: The post-nestling dependence period. Ostrich 6l: 43–49.

The post-nestling dependence period of the Bearded Vulture Gypaetus barbatus in southern Africa begins with the first flight of the young bird at 126 ± 2 days after latching (November-January) and ends during the pre-laying nod or the parent birds' next breeding attempt (April-June), a nod of about five months. For the first two weeks after first flit young bid remaine6 within about 200m of the nest, moving up to 800 m by the third week. By a month out of the nest young birds spent about 40% of the day in flight, moved up to 3 km from the nest, began bone-dropping and interacting with young birds from neighbouring nests. At six weeks they began to accompany their parents for part of some of their foraging trips, but returned to the nest alone, and by eight weeks they completed foraging forays with parents Pasting up to 3 h. At 2–3 months out of the nest young birds covered an area of about 42 km2, excluding the foraging trips with parents, by 3–4 months, 78km2 and 4–6 months, 168 km2. Parent birds delivered food for at least five months after the young bird's first flight. Young birds left their natal areas of their own accord, usually during the first month of their parents' next breeding attempt.  相似文献   

3.
Griffon vulture (Gyps fulvus) population surveys were conducted during 1996–2002 in the island of Crete (Greece) to document population status and structure. Fieldwork was carried out during the breeding period when birds could be monitored in their colonies. Total population size was estimated at 379 individuals (range = 341–417) with adult birds comprising 63%. The breeding population was estimated at 141 pairs, which were distributed on an average in 23 colonies per year (range = 16–30) while the mean number of breeding pairs that laid eggs was 98 (range= 64–126). Crete thus supports the largest insular population of the species in the world and hosts 70–80% of the breeding population of the species in Greece. Population density was estimated at 6.9 individuals/100 km2, 2.6 breeding pairs/100 km2 and 1.8 nesting pairs/100 km2. The average home range of an occupied colony (i.e., breeding group) was estimated at ca. 204 km2 producing a theoretical foraging range of 8 km radius around the breeding cliff. No trends in the total number of individuals and breeding pairs appeared to exist, although significant differences in population size of individual colonies occurred between the years. The majority of the population was concentrated in small-sized colonies, which showed a low occupancy rate. The number of abandoned sites and the colonization of new ones could represent a shift of breeding pairs to alternative colonies provoked by local food abundance and conspesific attraction.  相似文献   

4.
The status of the endemic and endangered lion-tailed macaque (Macaca silenus) has not been properly assessed in several regions of the Western Ghats of southern India. We conducted a study in Parambikulam Forest Reserve in the state of Kerala to determine the distribution, demography, and status of lion-tailed macaques. We laid 5km2 grid cells on the map of the study area (644km2) and made four replicated walks in each grid cell using GPS. We gathered data on lion-tailed macaque group locations, demography, and site covariates including trail length, duration of walk, proportion of evergreen forest, height of tallest trees, and human disturbance index. We also performed occupancy modeling using PRESENCE ver. 3.0. We estimated a minimum of 17 groups of macaques in these hills. Low detection and occupancy probabilities indicated a low density of lion-tailed macaques in the study area. Height of the tallest trees correlated positively whereas human disturbance and proportion of evergreen forest correlated negatively with occupancy in grid cells. We also used data from earlier studies carried out in the surrounding Anamalai Tiger Reserve and Nelliyampathy Hills to discuss the conservation status in the large Anamalai Hills Landscape. This landscape harbors an estimated population of 1108 individuals of lion-tailed macaques, which is about one third of the entire estimated wild population of this species. A conservation plan for this landscape could be used as a model for conservation in other regions of the Western Ghats.  相似文献   

5.
The relationship between changes in foraging patterns (inferred from waggle dance activity) and colony energy status (inferred from brood rearing activity, food storage, and colony weight) was examined for the African honey bee during a period of relative resource abundance and resource dearth. When resources were more abundant mean foraging distances (about 400 m) and foraging areas (4–5 km2) were small, and colonies recruited to 12–19 different sites per day. Colony foraging ranges and sites visited increased slightly during the dearth period, yet foraging continued to be concentrated within less than 10 km2. The degree to which fluctuations in foraging patterns were correlated with colony energy status varied with the availability of floral resources. During periods of relative forage abundance, increases in foraging range and number of sites visited were significantly correlated with increases in brood rearing and colony weight. In contrast, colonies examined during periods of resource dearth exhibited no correlations between foraging areas, foraging distances, and fluctuations in brood rearing, food storage, or colony weight. Thus, during dearth periods colonies may not be able to coordinate foraging patterns with changes in colony energy status.  相似文献   

6.
Population surveys of Sulawesi crested black macaques (Macaca nigra) were conducted on the Indonesian islands of Sulawesi and Bacan in 1992–1994 to assess the status of natural populations and determine habitat and anthropogenic factors affecting their population densities. We surveyed five sites for primates, including undisturbed and disturbed habitats. Data were collected on habitat structure and composition at two undisturbed and one disturbed forest site in which the primates were surveyed. The highest density of macaques was found in primary forest at Gunung Sibela Nature Reserve on Bacan (170.3 individuals/km2). Population density in logged forest on Bacan was high but significantly less than primary forest (133.4 individuals/km2). The high density of crested black macaques in primary forest on Bacan is best explained by the high carrying capacity found in primary forest. The lower food quantity and quality of food resources found in logged forest correlated with lower primate densities compared to primary forest. However, the large population of macaques in logged forest demonstrates the conservation value of such forest. Densities on Sulawesi at Tangkoko-Batuangas-DuaSudara Nature Reserve (TBDS) showed a continuing decline since earlier surveys. Primate densities were highest near the protected center of Tangkoko Reserve (66.7 individuals/km2). The peripheral areas of Batuangas and DuaSudara, even though adjacent and continuous, showed lower population densities of 46.4 and 23.5 individuals/km2, respectively. The best explanation for the continued decline of Macaca nigra populations at TBDS is hunting. Unless conservation measures are implemented immediately, M. nigra on Sulawesi risks extinction in the near future. Am. J. Primatol. 44:89–106, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

7.
J. Rolstad  P. Wegge 《Oecologia》1987,72(3):389-394
Summary Distribution and size of 38 capercaillie Tetrao urogallus leks were related to amount and configuration of old forest patches in two south-east Norwegian coniferous forests. The smallest occupied patch was 48 ha containing a solitary displaying cock. All patches larger than 1 km2 contained leks. Number of cocks per lek increased with increasing patch size. Number of leks per patch increased in a step-wise manner with one lek added for each 2.5–3 km2 increase in patch size. In large patches there was one lek per 3–5 km2 old forest, and density of lekking cocks was 2–2.5 per km2. In small patches density of cocks varied considerably. Density of cocks was not related to patch isolation or patch shape. However, among leks surrounded by 50–60% old forest within a 1 km radius, number of cocks increased with increasing old forest fine-graininess. We argue that when old forests cover more than 50%, a fine-grained mosaic may support higher densities of lekking cocks than a coarse-grained mosaic. Conversely, when old forests cover less than 50%, a fine-grained mosaic is unfavourable, because each old forest patch becomes too small and isolated. Finally, we present a predictive model of how old forest fragmentation influences density of leks, number of cocks per lek, and total density of cocks.  相似文献   

8.
The conservation of gorillas (Gorilla spp.) and chimpanzees (Pan troglodytes) depends upon knowledge of their densities and distribution throughout their ranges. However, information about ape populations in swamp forests is scarce. Here we build on current knowledge of ape populations by conducting line transect surveys of nests throughout a reserve dominated by swamp forest: the Lac Télé Community Reserve in northern Congo. We estimated gorilla and chimpanzee densities, distributions across habitats, and seasonal changes in abundance. Gorilla density was 2.9 gorillas km–2, but densities varied by habitat (0.3–5.4 gorillas km–2) with highest densities in swamp forest and terra firma mixed forest. Average chimpanzee density is 0.7 chimpanzees km–2 (0.1–1.3 chimpanzees km–2), with highest densities in swamp forest. Habitat was the best predictor of ape nest abundance, as neither the number of human indices nor the distance from the nearest village predicted nest abundance. We recorded significantly greater numbers of apes in terra firma forest during the high-water season than the low-water season, indicating that many gorillas and chimpanzees are at times concentrated in terra firma forest amid a matrix of swamp forest. Seasonally high numbers of apes on terra firma forest islands easily accessible to local people may expose them to substantial hunting pressure. Conversely, the nearly impenetrable nature of swamp forests and their low value for logging makes them promising sites for the conservation of apes.  相似文献   

9.
A census of wild Yakushima macaques (Macaca fuscata yakui) was carried out in a 23-km2 area of the western coast of Yakushima Island, Japan. We analyzed the census data to investigate changes in monkey distribution associated with the vertical distribution of vegetation. In the lowland coastal zone of 0–300 m above sea level (a.s.l.), 4.8 troops and 62.4–99.8 monkeys are estimated to have existed per km2. In the mountainside zones of 300–900 m a.s.l., the troop density decreased to 1.3–1.6 troops/km2. Since there was no difference in size between the coastal and mountainside troops, population density should decrease with altitude to about 30–36 monkeys per km2. On the other hand, 2.4 troops and about 36 monkeys were estimated to have inhabited per km2 in the mountain summit zone of 900–1,323 m a.s.l. Nature Conservation College  相似文献   

10.
The white-browed guan (Cracidae: Penelope jacucaca) is an endemic bird species to the Caatinga, the largest centre of dry forest in South America. This taxon was considered Vulnerable by the International Union for Conservation of Nature (IUCN) due to continued habitat loss within its distribution and intense hunting pressure that contributed to population declines. However, information on population aspects and habitat use by P. jacucaca, which is fundamental for monitoring its conservation status, is not available. We studied habitat use (analysed in a Generalized Linear Model) and population density (estimated by distance sampling) in a specific area in Northeast Brazil. Using species distribution modelling (SDM), forest cover loss data (performed in the MaxEnt program) and quantitative information about hunting, more rigorous estimates of the distribution limits, available habitat, and population declines of P. jacucaca were generated. Based on the IUCN criteria, we applied analysed data to reassess the conservation status of the white-browed guan. Local density was estimated at 13.1 individuals/km2 and the estimated number of individuals removed per year due to hunting was 121.7 in the forest cover area (110.46 km2) of the Serra de Santa Catarina. Consequently, the annual removal rate of hunted individuals in the study area corresponds to approximately 11% of the population. The habitat use analysis pointed to a strong positive association with seasonally dry deciduous forest (SDDF) vegetation and with arboreal vegetation. The SDM indicated a potential distribution (climatically favourable) area of 675,823 km2, and forest cover and loss calculations indicated a total of 81,307 km2 of available suitable habitat in 2013. Therefore, comparing these results to the IUCN criteria, we recommend that P. jacucaca remain in the Vulnerable category.  相似文献   

11.
A field study of mandrill was carried out from 1979 to 1983 in Cameroon for 27 months. Group size of mandrills ranged from 15 to 95 and composition was estimated by direct and indirect observations. The ratio of group size to one adult male was 13.9, larger than other baboon species except the drill. Solitary males were seen. The mandrill may have two types of groups: one-male and multi-male. The multi-male group was observed to split into subgroups, one of which was sometimes a one-male group. The multi-male subgroup was assumed to be composed of several one-male groups. The home range area of mandrills was estimated to be at least 5 km5 to 28 km2. Their large home range size could be related to their characteristic feeding pattern in the forest.  相似文献   

12.
From May, 1964, to September, 1965, the author made ecological and sociological studies of wild chimpanzees (Pan troglodytes) in Western Tanzania, East Africa. The vegetation of this area belongs to theBrachystegia andIsoberlinia savanna woodland. During the dry season, chimpanzees go out into the open forest and chiefly eat the hard seeds ofJulbernardia, Brachystegia, Isoberlinia, Pterocarpus, etc.The continuity of the group of chimpanzees is not stable but temporary, as has been reported byGoodall, etc. The author termed such a temporary group nomadic group. A big nomadic group, such as that consisting of 43 individuals at Filabanga, seems to be one unit of a chimpanzee's society.The nomadic range of the chimpanzees in the savanna woodland covers about 100 km2 (201 km2 in the Kasakati area). This is greater than that of the chimpanzees living in the forest, and such a large range has not been previously known among other non-human primates.This study was made possible by the Overseas Scientific Research Fund of the Ministry of Education.  相似文献   

13.
The ranging and grouping patterns of a gorilla group were studied during 27 months from 1990–1992 at the Bai Hokou study site, Central African Republic. The study group ranged far daily (average = 2.3 km/day) and had a large home range (22.9 km2), relative to mountain gorillas, and ranging patterns differed between years. During 1990–1992, the bimale study group foraged less cohesively and had more flexible grouping patterns than mountain gorillas. The study group sometimes split into two distinct foraging subgroups, each led by a silverback, and these subgroups occasionally slept apart (mean = 950 m apart). Lowland gorillas rely on many of the same fruit resources as sympatric chimpanzees, and under certain demographic situations gorillas, like sympatric chimpanzees, may adapt their foraging group size to reduce intragroup feeding competition. However, the fiber content of the lowland gorilla diet likely relaxes constraints on foraging party size and facilitates group cohesion relative to chimpanzees. Am. J. Primatol. 43:111–133, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

14.
Home range and habitat use of the sable Martes zibellina brachyura were studied in a cool-temperate mixed forest in northernmost Japan. In both sexes, some sables showed a wide range of migration without establishing home ranges and the others had home ranges of 0.50–1.78 km2 (mean: 1.12±SD 0.495 km2, n =6) which were not significantly correlated with body weight or age. The analysis of canine tooth annuli revealed that the maximum age was 5.5 years. The home ranges of some sables overlapped so extensively that the home ranges and even the core areas did not appear exclusive to other sables. We determined resting sites and foraging routes in snow in winter. Comparison of vegetation at the resting sites and foraging routes with habitat availability suggested that the sables preferred resting in dense-tree forests with many tree species and debris probably in order to avoid predators (red foxes) and strong wind and foraging in forests of climax succession which are usually rich in their prey such as voles and mice.  相似文献   

15.
《Ostrich》2013,84(3-4):185-192
Comparative surveys of bird species richness and abundance showed that a total of 69 bird species was recorded on 1 km transects (n = 996) through shrubland, with a total estimated density of birds of 32.7 ± 32.8 (S.D.) birds/km2, of which resident birds made up 24.4 ± 21.0 birds/km2, nomads made up 1.9 ± 11.7 birds/km2 and local nomads made up 6.3 ± 20.1 birds/km2. There was no correlation in general between total bird numbers or total bird biomass and rain, but numbers and biomass of nomads showed the strongest correlations with rainfall two months previously. A total of 86 species was recorded on 276 surveys along a 1 km stretch of drainage line woodland. Species richness varied from an average of about nine species to 24 species each month, and only showed a marked change during the 'dry' period of 1990 to early 1991. Density of birds in this woodland was 59.2 ± 20.8 birds/km. Biomass of birds was relatively constant throughout the study period, with marked increases in certain months when large species were present.  相似文献   

16.
Few data are available on gibbon populations in peat-swamp forest. In order to assess the importance of this habitat for gibbon conservation, a population of Hylobates agilis albibarbis was surveyed in the Sabangau peat-swamp forest, Central Kalimantan, Indonesia. This is an area of about 5,500 km2 of selectively logged peat-swamp forest, which was formally gazetted as a national park during 2005. The study was conducted during June and July 2004 using auditory sampling methods. Five sample areas were selected and each was surveyed for four consecutive days by three teams of researchers at designated listening posts. Researchers recorded compass bearings of, and estimated distances to, singing groups. Nineteen groups were located. Population density is estimated to be 2.16 (±0.46) groups/km2. Sightings occurring either at the listening posts or that were obtained by tracking in on calling groups yielded a mean group size of 3.4 individuals, hence individual gibbon density is estimated to be 7.4 (±1.59) individuals/km2. The density estimates fall at the mid-range of those calculated for other gibbon populations, thus suggesting that peat-swamp forest is an important habitat for gibbon conservation in Borneo. A tentative extrapolation of results suggests a potential gibbon population size of 19,000 individuals within the mixed-swamp forest habitat sub-type in the Sabangau. This represents one of the largest remaining continuous populations of Bornean agile gibbons. The designation of the Sabangau forest as a national park will hopefully address the problem of illegal logging and hunting in the region. Further studies should note any difference in gibbon density post protection.  相似文献   

17.
Eastern African coastal forests are located within the Swahili regional centre of endemism and Swahili-Maputaland regional transition zone in eastern Africa, between 1d? North and 25d? South, and 34—41d? East. Approximately 3167 km2 coastal forest remains: 2 km2 in Somalia, 660 km2 in Kenya, 697 km2 in Tanzania, 16 km2 in Malawi, 3 km2 in Zimbabwe and perhaps 1790 km2 in Mozambique. Most forests are small (≤ 20 km2), and all but 19 are under 30 km2 in area. Over 80% of coastal forest is located on government land, principally Forest Reserves; only 8.3 km2 is found in National Parks (6.2 km2 in Kenya (Arabuko-Sokoke), 2 km2 in Tanzania (Mafia Island) and tiny patches in Zimbabwe). Coastal forests are an important and highly threatened centre of endemism for plants (c 550 endemic species), mammals (6 species), birds (9 species), reptiles (26 species), frogs (2 species), butterflies (79 species), snails (>86 species) and millipedes (>20 species). Endemic species are concentrated in the forests of the Tana River, between Malindi in Kenya to Tanga in northern Tanzania, and in southern Tanzania. Forests with highest numbers of endemics are: lower Tana River, Arabuko-Sokoke, Shimba Hills (Kenya); lowland East Usambara, Pugu Hills, Matumbi Hills, Rondo and Litipo and other plateaux near Lindi (Tanzania); the Tanzanian offshore island of Pemba; Bazaruto archipelago (Mozambique), and tiny forest remnants of southern Malawi, eastern Zimbabwe and Mozambique. Most coastal forest endemics have a narrow distributional range, often exhibiting single-site endemism or with scattered or disjunct distributional patterns. They are best interpreted as relicts and not the result of recent evolution. Relictualization probably started with the separation of the ancient Pan African rainforest into two parts during the Miocene. The coastal forests are interpreted as a ‘vanishing refuge’ with the endemic species gradually becoming more and more relict (and presumably extinct) due historically to climatic desiccation and more recently to human destruction.  相似文献   

18.
Franklin J  Steadman DW 《PloS one》2010,5(12):e15685

Background

We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km2), Nayau (18.4 km2), and Aiwa Levu (1.2 km2), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity.

Methodology/Principal Findings

All trees >5 cm diameter were measured and identified in 23 forest plots of 500 m2 each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba.

Conclusions/Significance

Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance.  相似文献   

19.
In Drosophila, the dorsoventral axis is set up by the action of the dorsal group of genes and cactus, which have been ordered genetically in a linear pathway. We have identified and characterised krapfen (kra) as a new member of the dorsal-group genes. kra encodes for the Drosophila homologue of MyD88, an adapter protein operating in the mammalian IL-1 pathway. Epistasis experiments reveal that kra acts between the receptor Toll and the cytoplasmic factor Tube. We show that there is a direct interaction between Kra and Tube presumably mediated by the death domains present in both proteins. Tube in turn interacts with its downstream effector Pelle through death domain association. We therefore suggest that upon Toll activation, Kra associates with Pelle and Tube, in an heterotrimeric complex.  相似文献   

20.
We examined some models to predict the species richness of forest birds by the landscape-level factors at urban woods in Osaka Prefecture, Japan. The environmental factors examined were area (A) and elongation (E) of woodlands, the distance to mountain (D), distance to the nearest woods (> 10ha) (D 10), and the proportion of woods (Pw) and field (Pf) within 25 km2 outside the parks. The species–area relationship at 28 parks was better fitted by the power function (r2=0.704) and by the logistic function (r2=0.696) than by the exponential function (r2=0.637). A woods that was planted 7 years ago had extremely few species, but there was no significant difference in species richness between woods < 50 years old and those older. We built Principal Component Regression (PCR) models to predict the species richness, because collinearity was detected between D and Pw. PCR, log[S/(43–S)] = –1.820 + 0.224logA – 0.0113 D + 0.133 logPw – 0.0588E (R2 = 0.939, n = 27) was estimated. The species–area relationship was caused by difference in the occurrence pattern of bird species. This was attributable to the differences in feeding habit or micro-habitat use. We estimated that birds living between the forest interior and the edge, such as Dendrocopos kizuki, required at least 20 ha of woodland.  相似文献   

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