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 390 毫秒
1.
<正>活动节律和活动时间分配是动物行为学研究的两个重要方面,它们直接与动物的代谢和能量收支相关,但它们又会随环境不同不断调整。通过比较不同生态条件下动物的活动节律和活动时间分配,  相似文献   

2.
We studied reproductive behavior of free-ranging capped langurs (Trachypithecus pileatus) in the Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. Four species of primates —Trachypithecus pileatus, Macaca mulatta, M. assamensis, and Nycticebus bengalensis— live there. We studied the mating seasons, mating frequency, copulatory attempts, time spent in copulation, and interval between 2 successive copulations, gestation length, and interbirth interval of 4 groups of capped langurs during 2001–2003. We observed 2 mating seasons in a year. The first was larger, comprising 5 months (September–January), and the second was short, April and May. Mating was intensive in the morning session (0600–1000 h); 57% of total mating events occurred then. The average gestation period was 200 d. November was the most favorable month for breeding. In a year, 107 mating events occurred involving 5 adult females. Average time per mounting attempt is 12 s. Duration of mounting was the maximum in November. Interbirth interval was 23 months and 10 d. The birth season was 129 days, December–April; 53% of births occurred in February and March. Average birth rate is 0.386 birth/female/yr.  相似文献   

3.
We investigated the occurrence of scramble competition among Colobus vellerosus at Boabeng-Fiema, Ghana. If scramble competition had an impact on feeding efficiency among females, we expected a positive relationship between group size and the proportion of time spent feeding, day journey length, or home range size assuming resource availability is similar among the groups compared. We collected focal data on the feeding behavior of adult females and males over 11 mo (September 2000–August 2001) on 2 study groups: WW (n = 31–33 individuals) and B (n = 8–16 individuals). We also collected ranging data on group movements at half-hour intervals. The large group (WW1) had a significantly longer day journey length than the small group (B1), and females in the large group spent a significantly greater proportion of time feeding in the wet season, a period of low food availability, which suggests it may be a bottleneck period when food resources are scarce and Colobus vellerosus is close to being energy limited. The proximity data suggested females may be able to reduce or adjust for competition by having fewer neighbors when they feed and by spreading out when in a larger group. However, we found no relationship between home range size and group size or that females spent a greater proportion of time feeding than adult males did. Our results highlight the need to factor in differences in food availability when investigating scramble competition. Though equivocal, our results suggest scramble competition occurs among Colobus vellerosus, leading us to suggest there was a match with the potential competitive regime, i.e., food distribution.  相似文献   

4.
Previous studies of Trachypithecus species indicated that they were selective feeders that concentrated on relatively few food species/items. From January to December 2005, I quantified potential food availability and the food species/items eaten by five groups of François' langur (Trachypithecus francoisi) in the Mayanghe Nature Reserve (MNR), People's Republic of China. These langurs fed on 164 species, of which the top ten accounted for 51% of all feeding records. Langurs consumed more species (91) in the spring than in other seasons (73 summer, 75 autumn, and 67 winter), and only 38 species were consumed in all seasons. Nontree food species, such as bushes and lianas, accounted for 47% of the total feeding records and for a majority (68%) of the feeding records in winter. The annual diet consisted of leaves (64% of feeding records), fruit and seed (32%), and other nonfoliage items (4%); the langurs switched from being more folivorous in spring (93%) and summer (79%) to being more frugivorous in autumn (53%) and winter (56%). There was no correlation between the proportion of feeding records and the food availability in the most frequently consumed species, indicating that these langurs were selective feeders; there were significant correlations between consumption and abundance in both the entire set of 112 food species and the set of 86 infrequently consumed species, indicating that foods that are more available are eaten more frequently. It appeared that in the seasonal and disturbed habitat, feeding decisions and diet composition of the langur may be driven more by food availability, and less by animal's selectivity, than at other sites. The results indicate that François' langur copes with habitat alterations by broaden its dietary breadth; this has implications for the adaptive significance of dietary breadth, and has implications for future conservation strategies for species which exist in degraded habitats. Am. J. Primatol. 73:1176–1187, 2011. © 2011 Wiley Periodicals, Inc.  相似文献   

5.
Sixty nine hammerhead sharks, Sphyrna lewini, were tagged at Malpelo Island (Colombia) with ultrasonic transmitters during March 2006, 2007 and 2008, as part of a study to understand their residency at the island and their horizontal and vertical movements. Five sharks visited Cocos Island, 627 km distant from Malpelo. One of the sharks that appeared at Cocos Island also visited the Galapagos Islands, 710 km from Cocos, a month later. There is connectivity of Sphyrna lewini between Malpelo, Cocos and the Galapagos Islands, but the frequency of movements between the islands appears to be relatively low (<7% of the tagged sharks). The most common depth at which the sharks swam coincided with the thermocline (rs = 0.72, p < 0.01). The depth of the thermocline varied depending on the time of the year. Nocturnal detections of the sharks were more frequent during the cold season than during the warm season (W = 60, p < 0.01). We also found that hammerheads spent significantly more time on the up-current side of the island (Kruskal-Wallis = 31.1008; p < 0.01). This study contributes to the knowledge of hammerhead sharks not only in Malpelo Island but also at a regional level in the Eastern Tropical Pacific.  相似文献   

6.
The feeding and ranging patterns of a troop of hanuman langurs (Presbytis entellus, Colobinae) were studied in Kanha Tiger Reserve, central Indian Highlands for 1850 hr (1981–1982), in a mosaic of moist deciduous forest and anthropogenic meadow. The location, size, and species of each tree within the 74.5-ha troop annual range was known and the phenology of all tree species was sampled. According to scan sampling, the troop spent 25.7% of the daytime feeding, with range use concentrated on an island of dry deciduous forest. Whereas adjacent troops occupied only the periphery of the focal troop's range, all-male bands occupied its center, especially during takeover and infanticidal attacks. The troop consumed items from 60 of the 67 species of trees and woody climbers available; mature leaves (34.9% of feeding time), fruits (24.4%), leaf buds (10.6%), flowers and flower buds (9.5%), young leaves (3.6%), insects (3.0%), and gum (1%). The monthly utilization of fruit, open leaf buds, and flower buds is correlated significantly with their abundance, and the troop spent significantly more time feeding and less time moving when consuming mature leaves. Comparison of tree dispersion and langur ranging patterns suggests that the distribution of the most important food trees is a major influence on their range use.  相似文献   

7.
We studied the diet and food choice of 1 group of Fran?ois’ langurs (Trachypithecus francoisi) from August 2003 to July 2004 in the Nonggang Nature Reserve, Guangxi province, China. The langurs consumed 90 plant species, including 14 unidentified species. Leaves constituted 52.8% of the diet (38.9% young leaves and 13.9% mature leaves). Fruits and seeds accounted for 17.2% and 14.2%, respectively. Flowers and other items—including petioles, stems, roots, and bark—contributed to 7.5% and 7.4% of the diet, respectively. The langur diet varied according to season. They fed on more young leaves from April to September. Consumption of seeds, petioles, and stems increased between October and March, when young leaves were scarce. The diet shift corresponded to higher dietary diversity during the young leaf-lean period. Though the langurs fed on many plant species, 10 species accounted for 62.2% of the diet, only 2 of which were among the 10 most common tree species in vegetation quadrants, and the percentage of feeding records on a plant species and the percentage of individuals of the species in vegetation quadrants does not correlate significantly. Fran?ois’ langurs fed selectively, and they did not base their diet simply on the abundance of plant species in the habitat.  相似文献   

8.
We describe the activity patterns and time budgets of white-headed langurs that were confined to about 4 km2 of Longlin habitat in Fusui County, Guangxi Province, China. Between February and December 1996, we observed 6 langur groups monthly via group focal sampling and continuously recording the behavior of a focal group. Our results indicate that the langur groups selected stone caves on cliffs as sleeping sites. The daily activity pattern outside caves had 8 stages: (1) leaving the cave in the early morning; (2) moving and resting; (3) morning feeding; (4) moving a long distance; (5) resting at noon; (6) afternoon feeding; (7) moving back to the cave, and (8) entering the cave. Over the year, langurs spent a daily average of about 11.5 h outside caves and about 12.5 h inside caves. Moving accounted for 7% (spring), 7% (summer-autumn) and 13% (winter) of the time budget, and langurs spent 9% (summer-autumn) and 14% (spring) to 20% (winter) of their time feeding. Resting accounted for 79% of the time budget in spring, 84% in summer-autumn, and 57% in winter. Sunbathing only occurred in winter and accounted for about 10% of the time budget. One-way ANOVA and multiple range tests demonstrated that time budgets differed significantly among seasons. Langurs spent significantly more time feeding and moving in winter than in spring and summer-autumn, but significantly less time resting in winter than in spring and summer-autumn.  相似文献   

9.
We examined the spatial and temporal distribution of the foods of ursine colobus (Colobus vellerosus) at Boabeng-Fiema, Ghana as a means to predict the monopolizablity and usurpability of their food resources. Recent evidence suggests that food may not be limiting for folivorous primates, and that male sexual coercion may be a more important influence on folivore social organization. To address the question, we collected focal data on the feeding behavior of adult females and males over 11 mo (September 2000-August 2001) on 2 groups: WW (n = 31–33 individuals) and B (n = 8–16 individuals). We also conducted phenological monitoring and a tree survey of the two-group home ranges to establish food availability and distribution. We used 2 behavioral or organism-defined indicators of feeding behavior to assess potential resource contestability: food site residence time and distance moved between food sites. The colobus fed on a high diversity of species, most of their food trees were not clumped in distribution, within-tree interfood distances were short, and food trees were large. The only condition associated with the potential for monopolization was low food tree density. However, low food tree density may be offset by the colobus’ use of large trees. Taken together, the ecological and behavioral indicators suggest the food resources of Colobus vellerosus had a low potential for monopolization. Our results also indicate mature leaves had the longest food site residence time, which may suggest they should be the most usurpable plant part, though their presumed low quality and high abundance probably counteracted the effect. The pattern implied the potential for direct feeding competition among Colobus vellerosus at Boabeng-Fiema was low and agonistic interactions over food are not expected. Instead, a group size effect on feeding efficiency should be a more predominant influence on feeding efficiency, if food is limiting for the species.  相似文献   

10.
This paper presents the results of the first field study of the Brazilian endemic damselfish Stegastes rocasensis. Underwater data were collected at the Fernando de Noronha Archipelago (NE Brazil), where four sites were visually assayed for local territorial and feeding behaviors, as well as habitat use. S. rocasensis preferentially fed on turf and macroalgae, and during the afternoon period. Its territory size ranged from 0.26 to 13.86 m2 (1.61 ± 0.23 m2). Our findings suggest that adults preferably inhabit shallow, turf-rich areas, while sub-adults and juveniles occupy deeper areas with higher percent cover of invertebrates and hard corals, respectively. With regards to agonistic behaviors, pursuit of intruders was the most frequent reaction recorded (p < 0.001); the highest level of aggression was elicited by territorial herbivores (p < 0.001). Nevertheless, analysis of attacks elicited by different fish species within S. rocasensis’ territory showed that more attacks were launched on conspecifics than on other fish species.  相似文献   

11.
We studied the feeding ecology of white-headed langurs (Trachypithecus leucocephalus) from September 1997 to September 1998 in Fusui Rare and Precious Animal Reserve, SW Guangxi, China. We collected data in the central part of a group of limestone hills where the main population pool of langurs was located. The langurs fed on 50 plant species (belonging to 42 genera from 28 families) out of 164 species in the habitat (belonging to 112 genera from 48 families). Most of the food plant species were not common in the habitat. There are 16 important food species, including 6 key species. White-headed langurs were extremely folivorous, feeding mainly on young leaves (75% of total feeding records) of a broad range of less common plant species, which were in less disturbed areas. Thus, langur groups in high quality habitat had greater access to preferred foods, and the future of langurs in the Reserve may depend on immediate cessation of tree felling.  相似文献   

12.
A feeding trial was conducted to study the effect of montmorillonite superfine composite (MSC) on growth performance and tissue lead levels in pigs. Sixty barrows were randomly divided into two groups. They were fed the same basal diet supplemented with 0 or 0.5% MSC, respectively, for 100 days. Serum samples were collected and analyzed to study growth hormone secretion pattern. The mean lead concentration in selected tissues was analyzed. The results showed that average daily gain, average daily feed intake, and feed conversion ratio of pigs were improved by 8.97% (p < 0.05), 3.90% (p < 0.05), and 4.76% (p < 0.05), respectively, with the supplementation of MSC compared to the control group. Serum sample analysis indicated that peak amplitude, base-line level, and mean level of growth hormone were increased by 117.14% (p < 0.01), 42.78% (p < 0.01), and 51.75% (p < 0.01), respectively. Supplementation of MSC in the diet was found to significantly reduce lead concentration of tissues in blood, brain, liver, bone, kidney and hair.  相似文献   

13.
2006年4月至2007年4月在巴基斯坦克什米尔地区马希亚拉国家公园(Machiara National Park)对喜马拉雅灰叶猴(Semnopithecus entellus ajex)的栖息地利用和食性生物学进行研究。结果表明,冬天,叶猴首选的栖息地多为温暖湿润的针叶林和落叶林混交地区;夏天,它们则迁移至高海拔的亚高山灌木丛林里。喜马拉雅灰叶猴主要以植物的叶子为食,研究期间在该地区共发现49种被采食过的植物(夏季27种,冬季22种)。通过观察它们的所有食物,发现老叶(36.12%)比嫩叶(27.27%)更受欢迎,随后依次为果实17.00%、树根9.45%、树皮6.69%、花2.19%和根茎1.28%。  相似文献   

14.
Heat stress has important effects on the welfare of livestock. The effects of heat stress in cattle include changes in biological functions and behaviors. The aim of this study was to investigate the behavioral differences between light and heavy feedlot cattle reared in a hot environment. Sixteen male Holstein feedlot cattle were allocated to light (353.8 ± 15.5 kg, n = 8) and heavy (737.1 ± 15.8 kg, n = 8) groups according to their live weight and were kept in a semi-open feedlot barn. The individual behavioral response variables measured were standing, lying, feeding, drinking, ruminating, locomotor activity and elimination (urinating and defecating). The effects of group, day, observation time, replicate and all interactions were included in an explanatory statistical (GLM) model. The data were analyzed using the PROC GLM procedure of SAS. Overall, the heavy cattle spent more time standing (P < 0.001), lying (P < 0.001), and eliminating (P < 0.05) compared to the light group. In contrast, the light group spent more time eating, drinking and ruminating (P < 0.001). Locomotor activity did not differ significantly between groups (P > 0.05). During the day, heavy cattle spent more time standing (at 1600 hours) and less time eating in comparison with the light cattle (P < 0.001) (at 1300 and 1600 hours). Light and heavy feedlot cattle behaved differently in a hot environment. The findings of the study indicate that the welfare of the heavy Holstein feedlot cattle was impacted negatively when the ambient temperature was high (at 1300 hours).  相似文献   

15.
We collected data on sleeping site use of the François’ langur (Trachypithecus francoisi) between August 2003 and July 2004 at Nonggang Nature Reserve, China. We tested hypotheses regarding possible ultimate causes of sleeping site selection in light of our results. Langurs selected the ledges and caves on cliffs as sleeping sites. Of 23 identified sleeping sites, 7 were more frequently used than the others (≥9 times each, accounting for 64% of total observed nights). Langurs used most sleeping sites repeatedly, and reused some of them on consecutive nights; 4 consecutive nights were the longest run. We suggest that langurs choose sleeping sites to make approach and attack difficult by predators, and to increase familiarity so as to improve chances for escape. Langurs’ cryptic behaviors before entering sleeping sites and the rapid movement toward sleeping sites (4 min on average) with an increased level of vigilance may help to decrease the possibility of detection by predators. Access to food appears to have a profound influence on sleeping site selection in François’ langurs, as demonstrated by the langurs’ tendency to select sleeping sites close to their current main feeding sites. The position of sleeping site relative to the last feeding site of the day and the first feeding site of the subsequent morning indicated a strategy closer to that of a multiple central place forager than of a central place forager. Our results do not support the influences of other factors, e.g., avoidance of parasites, seeking comfort, and range or resource defense, on sleeping site selection.  相似文献   

16.
Spatial arrangement and social interactions of two sympatric and ecologically similar primate species, Hylobates klossii and Presbytis potenzianai, are described from field observations made between July 1972 and October 1974 on Siberut Island, Indonesia. Gibbon territories and langur home ranges overlap extensively. Because gibbons have the ability to supplant langurs at shared food sources, langurs are at a competitive disadvantage. To avoid or decrease the frequency of hostile interactions with gibbons, langurs locate their core areas on boundaries between adjacent gibbon territories, which permits langurs to retreat across these barriers in response to gibbon movements. Langurs further enhance segregration by leaving their sleeping trees earlier than gibbons, gaining additional feeding time on contested food sources. This form of interspecific spatial organization between gibbons and langurs resembles certain predator-prey spacing systems, where territorial boundaries between adjacent predators serve as sanctuaries for prey populations.  相似文献   

17.
I investigated the activity budget and diet of Yakushima macaques (Macaca fuscata yakui,)in warm temperate broad- leaved forest of Yakushima, Japan. Both time spent feeding and time spent moving varied considerably between half- months. However, total time spent in active behaviors— feeding time plus moving time— was stable. The composition of the diet also showed considerable variation between half- months. The macaques fed mainly on fruits, seeds,mature leaves, fallen seeds, flowers, and young leaves, each of which accounted for more than 30% of feeding time in at least 1 half- month. They also ate insects and fungi, but each of them comprised ≤ 25 and ≤ 8% of feeding time in any half- month, respectively. Time spent feeding on mature leaves, young leaves, flowers, or fallen seeds is positively correlated with total time feeding and is negatively correlated with time moving. In contrast, time feeding on fruits, seeds, insects or fungi is negatively correlated with time feeding and is positively correlated with time moving. Foraging on foods that have a low energy content, a high density, and a relatively even distribution— mature leaves— or that need much manipulation to be processed— flowers and fallen seeds— increased feeding time, while foraging on foods for which monkeys must search intensively in the forest— fruits, seeds, insects, and fungi— led to increased moving time. I examined foraging strategies of Yakushima macaques in terms of moving costs and the quality of food items. Regarding time feeding on fruits, which have more energy and may need less manipulation than other foods, as a benefit, and moving time as a cost, they seemed to employ a strategy that balanced the costs and benefits of foraging.  相似文献   

18.
The aim of the study was to determine the effect of the elements of the extract of seed from Emblica officinalis on antioxidant enzymes and osmotic fragility of erythrocytes membrane in normal as well as streptozotocin-induced severely diabetic albino Wister rats. The results revealed that the untreated diabetic rats exhibited increase in oxidative stress as indicated by significantly diminished activities of free radical scavenging enzymes such as catalase (CAT) and superoxide dismutase (SOD) by 37.5% (p < 0.001) and 18.6% (p < 0.01), respectively. However, the E. officinalis seed extract treatment showed marked improvements in CAT and SOD activities by 47.09% (p < 0.001) and 21.61% (p < 0.001), respectively. The enhanced lipid peroxidation by 30.87% (p < 0.001) in erythrocytes of untreated diabetic rats was significantly accentuated in the extract treated animals by 23.72% (p < 0.001). The erythrocytes showed increased osmotic fragility due to diabetes in terms of hemolysis. It attained the normal level in diabetic treated group. The findings thus suggest that E. officinalis seed extract has the potential to be exploited as an agent to boost the antioxidant system in the diabetic animal model. Laser-induced breakdown spectroscopy has been used as an analytical tool to detect major and minor elements like Mg, Fe, Na, K, Zn, Ca, H, O, C, and N present in the extract. The higher concentration of Ca (II), Mg (II) and Fe (II) as reflected by their intensities are responsible for the antioxidant potential of E. officinalis.  相似文献   

19.
2006年4月至2007年4月在巴基斯坦克什米尔地区马希亚拉国家公园(Machiara National Park)对喜马拉雅灰叶猴(Semnopithecus entellus ajex)的栖息地利用和食性生物学进行研究。结果表明,冬天,叶猴首选的栖息地多为温暖湿润的针叶林和落叶林混交地区;夏天,它们则迁移至高海拔的亚高山灌木丛林里。喜马拉雅灰叶猴主要以植物的叶子为食,研究期间在该地区共发现49种被采食过的植物(夏季27种,冬季22种)。通过观察它们的所有食物,发现老叶(36.12%)比嫩叶(27.27%)更受欢迎,随后依次为果实17.00%、树根9.45%、树皮6.69%、花2.19%和根茎1.28%。  相似文献   

20.
Golden langurs (Trachypithecus geei) are an endangered primate species in Bhutan. We discuss their evolution in terms of phylogeny, ecology, and biogeography. We test the hypothesis that rivers and mountains in Bhutan isolated a population of capped langurs (Trachypithecus pileatus) that later speciated into the morphologically distinct T. geei. Trachypithecus, the genus to which both capped and golden langurs belong, spread north from a paleorefuge in south China, and Semnopithecus (gray langurs) spread east and northward from a refuge in south India. We show that the 2 genera both arrived in Bhutan and were separated from each other by the Sunkosh River and Black Mountains. Likewise, a population of capped langurs isolated from parental populations by rivers speciated into the distinct golden langurs. We conducted field surveys covering the entire range of langurs in Bhutan. The Sunkosh River and Black Mountain range in west Bhutan isolate gray langurs and golden langurs from each other. In the east, the Manas River system (Manas-Mangde) served as a barrier between golden and capped langurs. However, it is an imperfect barrier and a contact zone between the 2 species occurred on the banks of the Mangde River. Second, we reconstructed the evolutionary history of the langurs of Bhutan via molecular phylogenetic tools. We sequenced the cytochrome b region (cyt b) of the mitochondrial DNA (mtDNA) to model a phylogeny. It revealed the distinct evolutionary paths of the golden, capped, and gray langurs. As predicted, golden and capped langurs are closely related to each other and to other species in Trachypithecus from Southeast Asia. The gray langur of Bhutan grouped into a distinct clade with conspecifics in Semnopithecus from India and Nepal. The south Indian clade of gray langurs is more ancient, with the Bhutan and Nepal gray langurs having diverged later, which fits with the glacial models of ice sheet retreats and colonization of South Asia by gray langurs from south India north toward the Himalayas. Likewise, the golden and capped langur clade are the most derived and divergent from the older groups of Trachypithecus in Southeast Asia, which also fits with paleorefuge models of recolonization by Trachypithecus into the rest of Southeast Asia and north toward the Himalayas from paleorefuges in Southeast Asia. As predicted, golden and capped langurs are closely related to each other and gray langurs are only distantly related to them. The divergence between capped and golden langurs is more recent, while the split between Trachypithecus and Semnopithecus is more ancient and took place before the Pliocene.  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