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 31 毫秒
1.
Sleeping site locations are important to free‐ranging primate groups. Sites are strategically selected by primates so as to optimize security, comfort and foraging efficiency. Data were collected on the distribution of sleeping sites of the Yunnan snub‐nosed monkey (Rhinopithecus bieti) between Sep 2005 and Sep 2006 at Gehuaqing in Baimaxueshan Nature Reserve, China. We identified 54 sleeping sites, which were used 137 times during the study period. These sleeping sites were distributed throughout the monkey group's total home range. R. bieti preferred certain sleeping sites over others: 63% of the sleeping sites were used 2 or more times in 13 months. Groups reused locations in an unpredictable long‐term pattern, but avoided using the same sleeping site on consecutive nights. To reduce the time and energetic costs of travel, monkeys preferred sleeping near commonly used feeding sites. We recorded 124 feeding sites in the home range, which were used 174 times. A total of 27 sleeping sites were also feeding sites, and all remaining sleeping sites were close to feeding sites. There was a positive correlation between the intensity of use of sleeping sites and feeding sites. The present study suggests that the availability and the location of immediate sources of food is a key factor in the choice of sleeping sites.  相似文献   

2.
Forest‐grazing enables the intake of high total antioxidant capacity (TAC) plants that might be beneficial for the TAC status of cattle. This study evaluated the relation between the seasonal foraging patterns of forest‐grazing Japanese Black (JB) heifers or the TAC levels in shrubs and trees and the changes of plasma TAC. We examined 12 JB heifers, four each of which were allocated to forest‐grazing (F), pasture‐grazing, and pen‐housed groups. The plasma TAC level in F heifers on July 26, August 13, 30 and September 17 were significantly higher than those on April 27 and June 4 (P < 0.05). In F group, the mean rates of foraging frequency (FF) of shrubs and trees during July 5–8 and September 13–16 were much higher than that during May 31–June 3 (P < 0.05). The rate of FF of grass significantly decreased later in the season (P < 0.05). The mean TAC levels in these shrubs and trees were higher than those in grasses, concentrates, and timothy hay. Results suggest that an important factor in the increase of plasma TAC in forest‐grazing cattle might be the increased foraging of TAC‐rich shrubs and trees during summer–fall.  相似文献   

3.
Sleep is one of the essential behaviors for mammals. The aims of this study were to validate the use of accelerometer for measuring sleeping posture of cattle. Duration of sleeping posture of seven Japanese Black cows from 19.00 to 07.00 hours was measured by both accelerometer and video, and a total of 67 accelerometer and video measurement sets were collected. We calculated Cohen's κ coefficient between accelerometer and video measurements and 91.5% of the κ‐values were >0.80. Intra‐ and inter‐observer coefficient of variance showed that specific acceleration waveform patterns of sleeping posture could be easily and accurately detected by independent observers. There were no significant differences in the frequency of sleeping posture occurrences between accelerometer and video measurements. We compared averaged sleeping posture bout, and the total sleeping posture time between accelerometer and video measurements using regression. In each trait, the slope was close to 1 and the intercept was not different from 0, which showed a strong agreement between accelerometer and video measurements. This shows that an accelerometer could accurately detect sleeping postures of cattle. We conclude that adequate measurements of sleeping postures can be made using an accelerometer.  相似文献   

4.
The scatter‐hoarding behavior of granivorous rodents plays an important role in seed dispersal and seedling regeneration of trees, as well as the evolution of several well‐known mutualisms between trees and rodents in forest ecosystems. Because it is difficult to identify seed hoarders and pilferers under field conditions by traditional methods, the full costs incurred and benefits accrued by scatter‐hoarding have not been fully evaluated in most systems. By using infrared radiation camera tracking and seed tagging, we investigated the benefits and losses of scatter‐hoarded seeds (Camellia oleifera) for 3 sympatric rodent species (Apodemus draco, Niviventer confucianus and Leopoldamys edwardsi) in a subtropical forest of Southwest China during 2013 to 2015. We established the relationships between the rodents and the seeds at the individual level. For each rodent species, we calculated the cache recovery rate of cache owners, as well as conspecific and interspecific pilferage rates. We found that all 3 sympatric rodent species had a cache recovery advantage with rates that far exceeded average pilferage rates over a 30‐day tracking period. The smallest species (A. draco) showed the highest rate of scatter‐hoarding and the highest recovery advantage compared with the other 2 larger species (N. confucianus and L. edwardsi). Our results suggest that scatter‐hoarding benefits cache owners in food competition, supporting the pilferage avoidance hypothesis. Therefore, scatter‐hoarding behavior should be favored by natural selection, and plays a significant role in species coexistence of rodent community and in the formation of mutualism between seeds and rodents in forest ecosystems.  相似文献   

5.
Picloram‐potassium and various mixtures of picloram with 2,4‐D amine, 2,4,5‐T ester or amine, or 2,4,5‐T ester alone were injected into incisions made in the cambium of standing Brachystegia spiciformis and Julbernardia globiflora trees. Each arboricide was tested at a range of application rates, at different times of the year and at three different sites for each species. Picloram‐potassium and 2,4,5‐T ester were also tested on Terminalia sericea trees. Glyphosate, MCPA, mixtures of mecoprop and 2,4,5‐T amine and different mixtures of 2,4‐D ester with 2,4,5‐T ester, cacodylic acid and Tandex were tested on B. spiciformis and J. globiflora trees at one site and only in January. Aboricides containing picloram, with or without the addition of 2,4‐D or 2,4,5‐T, were the most effective chemicals for the control of trees. Higher application rates were required to kill B. spiciformis and J. globiflora between May and October when they were not actively growing. T. sericea trees were susceptible to arboricide treatment throughout the year. The response of individual trees to treatment with arboricides appears to be related to size.  相似文献   

6.
Fleshy‐fruited plants in tropical forests largely rely on vertebrate frugivores to disperse their seeds. Although this plant–animal interaction is typically considered a diffuse mutualism, it is fundamental as it provides the template on which tropical forest communities are structured. We applied a mutualistic network approach to investigate the relationship between small‐fruited fleshy plant species and the fruit‐eating bird community in an intact evergreen forest in northeast Thailand. A minimum of 53 bird species consumed fruits of 136 plant species. Plant‐avian frugivore networks were highly asymmetrical, with observed networks filling 30% of all potential links. Whereas some of the missing links in the present study might be due to undersampling, forbidden links can be attributed to size constraints, accessibility and phenological uncoupling, and although the majority of missing links were unknown (58.2%), many were probably due to a given bird species being either rare or only a very occasional fruit eater. The most common frugivores were bulbuls, barbets and fairy‐bluebirds, which were responsible for the majority of fruit removal from small fleshy fruited species in our system. Migratory birds seemed to be a minor component of the plant‐frugivore networks, accounting for only 3% of feeding visits to fruiting trees; they filled 2% of the overall potential networks. The majority of interactions were generalized unspecific; however, Saurauia roxburghii Wall. appeared to be dependent on flowerpeckers for dispersal, while Thick‐billed Pigeons were only seen to eat figs.  相似文献   

7.
Trees were felled 150 mm above ground level and various mixtures of picloram with 2,4‐D araine, 2,4,5‐T amine in water solution or 2,4,5‐T ester in diesel oil were applied to the freshly‐cut surfaces. Mixtures of picloram/2,4‐D amine and picloram/2,4,5‐T amine, both water soluble, gave the highest kill rates when applied to trees in the growing season (October and May). The oil emulsifiable picloram/2,4,5‐T ester formulation tended to be effective throughout the year and high kill rates were frequently obtained with applications made in June or July. Application rates of picloram/2,4‐D amine or picloram/2,4,5‐T amine (expressed as g a.e. picloram per mm girth) required to kill 80% of the trees were 0,012–0,016 for A. karroo; 0,016–0,037 for T. sericea and 0,037 for J. globiflora. Few of the treatments applied to B. spiciformis trees resulted in kill rates of more than 65%.  相似文献   

8.
Bats have been demonstrated to be natural reservoirs of severe acute respiratory syndrome coronavirus (SARS CoV) and Middle East respiratory syndrome (MERS) CoV. Faecal samples from 248 individuals of 20 bat species were tested for partial RNA‐dependent RNA polymerase gene of CoV and 57 faecal samples from eight bat species were tested positive. The highest detection rate of 44% for Scotophilus kuhlii, followed by 30% for Rhinolophus monoceros. Significantly higher detection rates of coronaviral RNA were found in female bats and Scotophilus kuhlii roosting in palm trees. Phylogenetic analysis classified the positive samples into SARS‐related (SARSr) CoV, Scotophilus bat CoV 512 close to those from China and Philippines, and Miniopterus bat CoV 1A‐related lineages. Coronaviral RNA was also detected in bat guano from Scotophilus kuhlii and Myotis formosus flavus on the ground and had potential risk for human exposure. Diverse bat CoV with zoonotic potential could be introduced by migratory bats and maintained in the endemic bat population in Taiwan.  相似文献   

9.
Local extinction or population decline of large frugivorous vertebrates as primary seed dispersers, caused by human disturbance and habitat change, might lead to dispersal limitation of many large‐seeded fruit trees. However, it is not known whether or not scatter‐hoarding rodents as secondary seed dispersers can help maintain natural regeneration (e.g. seed dispersal) of these frugivore‐dispersed trees in the face of the functional reduction or loss of primary seed dispersers. In the present study, we investigated how scatter‐hoarding rodents affect the fate of tagged seeds of a large‐seeded fruit tree (Scleropyrum wallichianum Arnott, 1838, Santalaceae) from seed fall to seedling establishment in a heavily defaunated tropical forest in the Xishuangbanna region of Yunnan Province, in southwest China, in 2007 and 2008. Our results show that: (i) rodents removed nearly all S. wallichianum seeds in both years; (ii) a large proportion (2007, 75%; 2008, 67.5%) of the tagged seeds were cached individually in the surface soil or under leaf litters; (iii) dispersal distance of primary caches was further in 2007 (19.6 ± 14.6 m) than that in 2008 (14.1 ± 11.6 m), and distance increased as rodents recovered and moved seeds from primary caches into subsequent caching sites; and (iv) part of the cached seeds (2007, 3.2%; 2008, 2%) survived to the seedling stage each year. Our study suggests that by taking roles of both primary and secondary seed dispersers, scatter‐hoarding rodents can play a significant role in maintaining seedling establishment of S. wallichianum, and are able to at least partly compensate for the loss of large frugivorous vertebrates in seed dispersal.  相似文献   

10.
During a mast‐fruiting event we investigated spatial variability in fruit availability, consumption, and seed removal at two sympatric tree species, Manilkara bidentata and M. huberi (Sapotaceae) at Nouragues Natural Reserve, French Guiana. We addressed the question of how Manilkara density and fruits at the community level might be major causes of variability in feeding assemblages between tree species. We thus explored how the frugivore assemblages differed between forest patches with contrasting relative Manilkara density and fruiting context. During the daytime, Alouatta seniculus was more often observed in M. huberi crowns at Petit Plateau (PP) with the greatest density of Manilkara spp. and the lowest fruit diversity and availability, whereas Cebus apella and Saguinus midas were more often observed in M. bidentata crowns at both Grand Plateau (GP), with a lowest density of M. bidentata and overall greater fruit supply, and PP. Overall, nearly 53% and 15% of the M. bidentata seed crop at GP and PP, respectively, and about 47% of the M. huberi seed crop were removed, otherwise either spit out or defecated beneath trees, or dropped in fruits. Small‐bodied primates concentrated fallen seeds beneath parent trees while large‐bodied primate species removed and dispersed more seeds away from parents. However, among the latter, satiated A. seniculus wasted seeds under conspecific trees at PP. Variations in feeding assemblages, seed removal rates and fates possibly reflected interactions with extra‐generic fruit species at the community level, according to feeding choice, habitat preferences and ranging patterns of primate species.  相似文献   

11.
Lilian's Lovebird Agapornis lilianae is a non-excavating cavity user of mopane Colophospermum mopane woodlands. We investigated roost characteristics of Lilian's Lovebirds in Liwonde National Park, Malawi. We quantified tree and roost site variables for roost and non-roost trees. Sixty-six roosts were found. Roosts were in large tall mopane trees with a mean diameter at breast height (dbh) of 57.4 ± 1.64?cm, a mean height of 16.5 ± 0.42?m, and with a mean cavity entrance height of 10.0 ± 0.05?m. Non-roost areas had significantly smaller trees (mean dbh = 39.4 ± 1.72?cm). Human disturbance was low in both areas, but browsing of African elephant Loxodonta africana was evident by large areas of stunted mopane woodland recorded in non-roost areas. We recommend that the current Liwonde National Park vegetation map be updated to highlight areas of stunted mopane woodland unsuitable for Lilian's Lovebird roosts. The impact of elephant browsing on large mopane trees should be assessed to understand its impact on the availability of suitable cavities for lovebirds and other tree cavity reliant vertebrate species.  相似文献   

12.
Ectophylla alba is a tent-making bat that roosts in mixed-sex clusters comprising adults and offspring. Our goal was to determine the genetic identity of individuals belonging to different roosting groups. We tested the hypothesis of kin selection as a major force structuring group composition. We used 9 microsatellites designed for E. alba to determine the genetic identity and probability of parentage of individuals. We analyzed parentage and kinship using the software ML-Relate, GenAIEx, and Cervus. The obtained relationship probabilities (0.5) revealed a clear maternal relationship between female adults and offspring with allele compatibility, and at least 5 relationships between male adults and pups. We found a low degree of relatedness within roosting groups. Between roosting groups at different sites, the mean probability of a half-sibling relationship ranged from 0.214 to 0.244 and, for full-sibling relationship, from 0.383 to 0.553. Genetically, adult individuals were poorly related within clusters, and kinship as an evolutionary force could not explain group membership.  相似文献   

13.
Postural origin theory predicts that body postures are related to hand preference in nonhuman primates due to hemispheric specialization. Foot preference, especially in manipulating objects, is also a good predictor of hemispheric specialization in humans. We studied limb (hand and foot) preferences in 11 captive adult black‐and‐white snub‐nosed monkeys (Rhinopithecus bieti) to see how limb preference is influenced by postures and foot manipulation. Hand preference was significantly different for this group between quadrupedal standing and clinging postures, and sitting and clinging postures, but not between bipedal standing and clinging postures. Individuals were significantly more likely to use the right hand in the clinging posture than in quadrupedal standing or sitting postures. In the sitting posture, individuals maintained their respective hand preference even when the food was on the other side of the body. There was a gender difference in the sitting posture, where females preferred their right hand but males preferred their left. Individuals who did not routinely use their feet to manipulate objects, compared to those who did, shifted to greater right hand use from the clinging posture to the bipedal posture. One male individual and his offspring were more likely to use their feet to manipulate objects than the rest of the monkeys. In the present study, we reveal the first evidence of a postural effect on hand preference in R. bieti as well as a foot preference in this species. Our results mostly agree with the postural origin theory and hemispheric specialization.  相似文献   

14.
2004年3～9月,我们对卧龙自然保护区核桃坪基地野化培训大熊猫个体＂祥祥＂的夜宿地组成结构进行了初步观察,并采用主成分分析（PCA）对471组夜宿地数据所涉及的7种结构因子（廊道、竹林、余竹堆、岩石、乔木、倒木、灌草丛）进行了统计分析。结果表明：在大熊猫＂祥祥＂的夜宿地结构中,＂廊道＂、＂竹林＂和＂乔木＂是最主要的3个因子。经单因素方差分析检验表明,在对地势的选择中,＂祥祥＂偏爱坡度5°～30°的缓坡竹林（P〈0.01）;环境温度增加是造成＂祥祥＂选择在树上休息的主要原因（P〈0.05）;在拐棍竹发笋期,随着活动的增加,夜宿地数量明显增多（P〈0.01）。观察结果反映出＂祥祥＂对自然环境的主动适应,对夜宿地的分析研究结果对今后的野化培训选址和培训方式提供了有益启示。  相似文献   

15.
Extant colobines represent a predominantly arboreal primate radiation, but there are outliers such as some species of snub‐nosed monkeys (Rhinopithecus spp.) that utilize both arboreal and terrestrial substrates. We quantified the degree of terrestriality and the distribution of individuals across canopy levels, the extrinsic and intrinsic determinants and constraints of strata association as well as use of postures in relation to behavior and food sources in a wild population of Yunnan snub‐nosed monkeys (Rhinopithecus bieti) in the Samage Forest, China. The subjects spent 80.5% of the observation time in the trees and 19.5% on the ground. Ground use occurred most frequently in the context of travelling (61%) and less often in the context of feeding and resting (30% combined). Adult males frequented the ground significantly more often than other age‐sex classes. Age‐sex differences were also apparent in substrate preferences, which likely reflect body weight constraints. Adult males were significantly more associated with solid substrates and less with terminal branches than adult females and juveniles. Juveniles were seen more often on unstable ground (i.e. on thin and oblique branches) and in the upper canopy. Substrate use also varied with behavior: feeding was much more common in the upper stratum, outer canopy, on highly inclined and thin branches, as compared to resting. Severe weather also influenced canopy use in that tree crowns were used less often during periods of snowfall. The most frequently exhibited resting and feeding postures was sitting. Standing and suspensory postures were most often used in the context of feeding on lichens.  相似文献   

16.
By tracking the fate of individual seeds from 6 frugivore‐dispersed plants with contrasting seed traits in a fragmented subtropical forest in Southwest China, we explored how rodent seed predation and hoarding were influenced by seed traits such as seed size, seed coat hardness and seed profitability. Post‐dispersal seed fates varied significantly among the 6 seed species and 3 patterns were witnessed: large‐seeded species with a hard seed coat (i.e. Choerospoadias axillaries and Diospyros kaki var. silvestris) had more seeds removed, cached and then surviving at caches, and they also had fewer seeds predated but a higher proportion of seeds surviving at the source; medium‐sized species with higher profitability and thinner seed coat (i.e. Phoebe zhennan and Padus braohypoda) were first harvested and had the lowest probability of seeds surviving either at the source or at caches due to higher predation before or after removal; and small‐seeded species with lower profitability (i.e. Elaeocarpus japonicas and Cornus controversa) had the highest probability of seeds surviving at the source but the lowest probability of seeds surviving at caches due to lower predation at the source and lower hoarding at caches. Our study indicates that patterns of seed predation, dispersal and survival among frugivore‐dispersed plants are highly determined by seed traits such as seed size, seed defense and seed profitability due to selective predation and hoarding by seed‐eating rodents. Therefore, trait‐mediated seed predation, dispersal and survival via seed‐eating rodents can largely affect population and community dynamics of frugivore‐dispersed plants in fragmented forests.  相似文献   

17.
There is growing evidence that dilated cardiomyopathy may be a major cause of death in captive Livingstone's fruit bats (Pteropus livingstonii). Therefore, the primary aim of this prospective, exploratory study was to examine whether a systematic cardiac ultrasound protocol is feasible in this critically endangered species and to report basic measures of cardiac structure and function from a cohort of apparently healthy bats. A secondary aim was to test the effect posture (dorsal recumbency vs. roosting) has upon cardiac function in this species. Transthoracic echocardiograms, including 2D, Doppler, and tissue Doppler measures of cardiac structure and function were completed as part of routine health examinations for bats at a single center (n = 19). Bats were then grouped by age and disease status and the mean and range data reported for each group. In healthy adult bats, with the exception of a reduction in heart rate (P ≤ 0.05), right atrial systolic area (P ≤ 0.05), and right ventricular velocity during atrial contraction, there were no significant changes in cardiac structure or function in response to the roosting position. However, in the bats presenting with dilated cardiomyopathy the current data suggest that left ventricular ejection fraction is improved while roosting. Further work is required to confirm our initial findings, generate diagnostic reference intervals, and explore the causes of dilated cardiomyopathy in this species.  相似文献   

18.
O.B. Kok 《African Zoology》2013,48(2):155-183
Mousebirds (Coliiformes) exhibit well-developed communal roosting behaviour as well as a pronounced capacity for facultative hypothermic responses. We recorded body temperature (Tb)) in speckled mousebirds (Colius striatus) under semi-natural conditions in outdoor aviaries, and examined interactions between behavioural and metabolic thermoregulation by experimentally manipulating food availability and communal roosting behaviour. When food was available ad libitum, mousebirds roosting in a cluster maintained approximately constant rest-phase Tb, with 32°C < Tb < 42°C. By contrast, rest-phase Tb in single mousebirds decreased at 0.5°C/hr and minimum rest-phase Tb was significantly lower than when clustering. When food availability was restricted, the mousebirds exhibited facultative hypothermic responses that were less pronounced in clustering groups (minimum rest-phase Tb = 33.3°C, circadian amplitude of Tb = 9.5°C) compared to single birds (minimum rest-phase Tb = 30.7°C, circadian amplitude of Tb = 11.8°C). When clustering, rest-phase Tb was highly synchronized among individuals. Our data reveal that communal roosting has profound consequences for rest-phase thermoregulation in C. striatus, and provide further insights into the potential role of physiological constraints in the evolution of avian sociality.  相似文献   

19.
This study aimed to investigate the immunoexpression of Ki‐67 protein, androgen receptor (AR), and estrogen receptor beta (ERβ) in testicular tissues of male pigs immunocastrated using GnRH vaccine (Improvac?, Zoetis Co., Ltd., Thailand) with different times. Totally, 30 male pigs were classified by castration protocol into three groups: T1 (n = 10) consisted of pigs immunocastrated at 14 and 18 weeks of age, T2 (n = 10) included pigs immunocastrated at 9 and 19 weeks of age, and C (n = 10) contained intact pigs. The results revealed that testicular length of pigs in C was longer than that of both T1 (8.1 ± 0.76 vs 6.5 ± 0.5 cm, p < 0.001) and T2 (8.1 ± 0.76 vs 6.9 ± 1.0, p = 0.007). Spearman correlation coefficients showed negative correlation between testicular length and H‐score of AR (r = ?0.38, p = 0.037), as well as positive correlation between testicular length and Ki‐67 index (r = 0.602, p < 0.001). Generally, mean Ki‐67 index and mean H‐scores of AR and ERβ of pigs in T1 were not different from those in T2 (p > 0.05). However, mean Ki‐67 index and mean AR H‐scores of T1 and T2 were significantly different from C group (p < 0.05). In summary, the immunocastration significantly affected testicular length, including expressions of Ki‐67, AR, and ERβ in pig testes. Moreover, the duration between two shots of GnRH vaccine could be extended from 4 to 10 weeks without difference in Ki‐67 protein, AR, and ERβ immunoexpressions.  相似文献   

20.
Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long‐term adaptability to an increasingly human‐dominated landscape. The aim of this study was to determine and compare the influence of ground‐based food availability, remotely sensed plant productivity, and indigenous forest use on the ranging patterns of the endangered samango monkey (Cercopithecus albogularis schwarzi). We collected monthly ranging data on two habituated samango monkey groups, from February 2012 to December 2016, from our field site in the Soutpansberg Mountains, South Africa. We used linear mixed models to explore how food availability, plant productivity, and indigenous forest use influenced monthly ranging patterns, while controlling for group size, number of sample days and day length. We found that as more areas of high plant productivity (derived from remotely sensed EVI) were incorporated into the ranging area, both total and core monthly ranging areas decreased. In addition, both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area. However, we found no effect of either ground‐based food availability or remotely sensed plant productivity on ranging patterns. Our findings demonstrate the behavioral flexibility in samango monkey ranging, as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches. In addition, we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging, forest‐dwelling guenon, over ground‐based estimates of food availability.  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