麻阳河自然保护区黑叶猴夏季的夜宿行为

因昼行性灵长类动物一天中相当一部分时间在其夜宿地度过,其夜宿行为在一定程度上影响着它们的活动方式与行为特点(Anderson,1998).对夜宿行为的观察可收集白天无法收集到的灵长类社会活动和社会关系的信息,如夜宿地分布(sleeping site)、睡眠时间(time)、睡眠抱团组成(huddling)等(Takahashhi,1997;Ogawa etal.,2007;黎大勇,2010),灵长类夜宿行为的研究对于分析了解其白昼活动方式与行为适应特点具有重要的启迪作用(Anderson,1998).     

西藏红拉雪山滇金丝猴的夜宿地与夜宿树选择

树栖灵长类动物要在夜宿地度过半生以上的时光,因此选择合适的夜宿地及夜宿树对其存活尤为关键。影响夜宿地以及夜宿树选择的主要因素是逃避天敌捕食,但对于栖息在温带森林的灵长类而言,还必须面对低 温以及食物缺乏等因素的影响。2003 年6 月至2005 年3 月,采用跟踪猴群,记录夜宿地并依据地面粪便颗粒数确定夜宿树,在西藏红拉雪山自然保护区对小昌都滇金丝猴的夜宿地及夜宿树进行了研究。结果表明:在主要 研究时间段196 d 夜宿地记录中猴群使用了101 个夜宿地,使用2 次以上的夜宿地有67 个,夜宿162 d。夜宿地全部位于针叶林中,冬季夜宿地主要分布在向阳、背风和低海拔处。比较重复利用夜宿次数多与夜宿次数少的树发现:夜宿多的树高大,底枝长,而与底枝高没有差异。比较夜宿和不过夜的树发现:夜宿树高大、底枝长。这些特点表明小昌都猴群夜宿地及夜宿树的选择可能受到逃避天敌和体温调节的影响。     

Sleeping Site Use by <Emphasis Type="Italic">Trachypithecus francoisi</Emphasis> at Nonggang Nature Reserve,China

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.     

Sleeping site ecology in a rain-forest dwelling nocturnal lemur (Lepilemur mustelinus): implications for sociality and conservation

Suitable sleeping sites as potentially restricted resources are suggested to shape sociality in primates. We investigated sleeping site ecology of a rain-forest dwelling sportive lemur in eastern Madagascar for the first time. Using radiotelemetry, we characterized the type, quality and usage of sleeping sites as well as social sleeping habits of 11 focal individuals of the weasel sportive lemur (Lepilemur mustelinus) during the dry and the onset of the rainy season. Morphometric measurements provided additional information. The sexes showed an unusual sexual dimorphism for primates. Males and females did not differ in body length, but females surpassed males in body mass suggesting female dominance. Both sexes used dense vegetation and holes in hollow trees high above the ground as shelters for sleeping during the day. No sex difference in the quality of tree holes was found, but focal individuals used tree holes more often than open sleeping sites in dense vegetation. Both sexes showed high sleeping site fidelity limited to two to six different sites that they used primarily solitarily. The results imply that suitable sleeping sites are limited and survival of this species will strongly depend on the availability of mature rain forests with suitable hollow trees. Furthermore, these findings provide evidence of a solitary sleeping and ranging system in this rain-forest dwelling sportive lemur with suitable sleeping sites as defendable resources.     

Sleeping Sites of <Emphasis Type="Italic">Rhinopithecus brelichi</Emphasis> at Yangaoping,Guizhou

Arboreal primates spend about half of their lives at sleeping sites; hence, selection of sleeping sites is crucial for individual survival, and data concerning them is important for conservation efforts. We collected data on sleeping sites for a group of the endangered snub-nosed monkey (Rhinopithecus brelichi) at Yangaoping (27°58′N, 108°45′E) from January 2006 to December 2007. All sleeping sites were located in the mid-slope and in the shadow of ridges facing the northeast and southeast. The monkeys remained quiet while entering and occupying sleeping sites, and slept in evergreen species during the cold season (December–March). Trees in sleeping sites were similar in height and girth at breast height to those elsewhere, but some trees in lower areas were larger. The monkeys usually slept in close proximity to the last feeding spot, and their daily activities usually occurred around the sleeping site. Areas adjacent to sleeping sites were used more intensively than those not adjacent. Monkeys left the sleeping sites later in the morning in the cold season. These behavioral responses suggested that predation risk, thermoregulation, and climate stresses are the main determining factors in the selection of sleeping sites for this temperate monkey.     

Do sleeping king penguins influence the movement of conspecifics through a colony?

Within a breeding colony, movements of penguins to and from territories can be associated with high energetic costs and risks of injury induced by the high aggressiveness of territorial breeders. Here, we tested whether the presence of sleeping king penguins (namely non-aggressive birds) could influence the trajectory of walking conspecifics. Also, we determined how an aggressive response from the sleeping individual's neighbours could affect the trajectory adopted by a travelling bird. We observed 150 sleeping king penguins on Possession Island (Crozet Archipelago) during the breeding season and determined whether or not travelling birds walk preferentially beside sleeping individuals. Moving penguins not attacked by territorial birds directly surrounding the sleeping individual walked preferentially beside it in 80.3% of the observations. However, birds attacked by the sleeping individual's neighbours walked beside the sleeping bird in only 27.9% of the cases. Whether the sleeping individual's neighbours were directly facing the intruder or not did not affect the probability of the intruder being attacked. Hence, travelling penguins actively chose to walk beside a sleeping individual when not attacked by the latter's neighbours. This striking tropism could represent an adapted motivated behaviour, reducing energetic costs and risks of injury associated with fighting. Accepted: 21 December 1998     

Effects of Habitat Degradation on Sleeping Site Choice and Use in Sahamalaza Sportive Lemurs (Lepilemur sahamalazensis)

Sleeping sites may be beneficial for animals in terms of thermoregulation, proximity to foraging sites, and protection from predators and infectious diseases. The abundance of adequate sleeping sites is thus essential for the survival of primates. We investigated microhabitats around sleeping sites, and the influence of habitat degradation on sleeping site choice and usage, in the nocturnal Sahamalaza sportive lemur, Lepilemur sahamalazensis. We used quarter point sampling (N?=?315) to describe five forest fragments and 57 sleeping sites and continuous focal animal sampling (N?=?45) to determine the diurnal activity budget, to determine whether individuals inhabiting different fragments or sleeping site types showed different levels of vigilance. Our results suggest that tall trees with large crowns, a high density of small trees, and dense canopy are particularly important for sleeping site choice. Microhabitat structure around sleeping sites did not differ between forest fragments or sleeping site types. Diameter at breast height, crown diameter, canopy cover, and bole height were similar for all sleeping trees, as were the number of lianas in trees with tree-tangle sleeping sites, and the volume of tree holes. Tree holes used as sleeping sites were most often found in dead trees of Bridelia pervilleana (50–62.5 %), whereas tree tangle sites were most often located in Sorindeia madagascariensis (20–62.5 %). Lemurs were active 5–14 % of the daytime, although they never left their sleeping sites or fed. Individuals occupying tree holes had higher levels of activity than those in tree tangles, and those in more degraded fragments were more active. Our results suggest that Sahamalaza sportive lemurs choose their sleeping sites according to specific habitat characteristics, and that factors associated with old and intact forest are likely to be crucial for their survival.     

Nocturnal sleeping habits of the Yunnan snub‐nosed monkey in Xiangguqing,China

Weather, predation, and social organization are hypothesized to influence sleeping habits of nonhuman primates at night. To investigate how the Yunnan snub‐nosed monkey (Rhinopithecus bieti) prepares for and behaves during cold nights in their harsh alpine forest habitat (above 3,000 m), we studied the sleeping habits of the 171 one‐male units (OMU) in one group for 12 months at Xiangguqing in the Baimaxueshan Nature Reserve, China. It took 20.2 min from the time the study group entered a sleeping site until they fell asleep. This duration was consistent over seasons. On average, sleeping time was 11.5 hr per night over the year. Seasonal mean lengths of sleeping time varied significantly, however, and ranged from 10 to 13 hr per night, correlating with night length. Two sleeping styles were distinguishable: solitary sleeping and huddled sleeping. That adult males in OMUs principally slept alone. This is likely to reflect night‐time guarding behavior. Female–juvenile and female–infant dyadic huddles were the most prevalent sleeping unit (42% of all observed data), and the monkeys employed female‐biased huddling during nocturnal sleep. Huddled sleeping group size showed significant seasonal variation, with the largest huddle (eight individuals) occurring in winter. Climate and social organization profoundly influence the nocturnal sleeping habits of R. bieti, while huddling behavior may help shield animals from cold nights and provide additional protection against predators. Am. J. Primatol. 72:1092–1099, 2010. © 2010 Wiley‐Liss, Inc.     

Golden lion tamarin sleeping-site use and pre-retirement behavior during intense predation

Sleeping sites, their patterns of use, and cryptic pre-retirement behavior mitigate predation risk at sleeping sites and could influence prey fitness. We evaluated sleeping-site usage for 10 groups of golden lion tamarins (GLTs) from a population that recently suffered a substantial decline due to predation at sleeping sites. We recorded the average number of nights that groups spent at their different sleeping sites to determine whether patterns of sleeping-site use were influenced by predation risk, as measured by the rate of encounters with predators, or the availability of suitable sleeping sites, as measured by the size of a group's home range and amount of mature forest within their home range. In addition, we measured travel speed to sleeping sites and compared this speed with that recorded at other times of day. GLT groups spent more nights on average at each of their sleeping sites compared to other callitrichid species for which data are available. Predation risk and habitat characteristics were not significant predictors of how many times groups used each of their different sleeping sites. Groups significantly increased their travel speed just before entering the sleeping site. Rapid locomotion to secure tree cavities may help GLTs avoid crepuscular and nocturnal predators; however, we speculate that this strategy failed numerous GLTs in our study population during the previous decade because they used sleeping sites that were accessible to predators.     

Pair-specific usage of sleeping sites and their implications for social organization in a nocturnal Malagasy primate, the Milne Edwards' sportive lemur (Lepilemur edwardsi)

Safe sleeping sites may be a limited resource crucial for survival. In order to investigate their potential significance for social organization in nocturnal primates, we analyzed the spatial distribution of daily sleeping sites, their characteristics, their usage, and sleeping group compositions in the nocturnal Milne Edwards' sportive lemur during a 6-month field study in the dry deciduous forest of northwestern Madagascar. Sexes did not differ either in body size or in body mass. Sleeping sites were used almost exclusively by adult male-female pairs. Individuals showed a high sleeping-site fidelity limited to 2-3 different sleeping sites in close vicinity during the whole study period. Most females showed a higher fidelity to one distinct sleeping site than their male partners. Sleeping groups consisted of one adult male and one adult female and remained stable in composition over the whole study period. Exclusive pair-specific usage of sleeping sites suggests sleeping site related territoriality of male-female pairs, perhaps influenced by inter- and intrasexual resource competition. Results give first insights into the distribution patterns and social organization of this species. They imply dispersed monogamy for the Milne Edwards' sportive lemur, with sleeping sites as a potentially restricted and defendable resource.     

Multiple Ecological Factors Influence the Location of Proboscis Monkey (<Emphasis Type="Italic">Nasalis larvatus</Emphasis>) Sleeping Sites in West Kalimantan,Indonesia

Multiple ecological factors have been hypothesized to influence primate sleeping site selection. Testing multiple hypotheses about sleeping site selection permits examination of the relative strength of distinct ecological factors and expands our ability to understand how selection pressures influence primate sleeping behavior. Here we examine how avoidance of biting insects, thermoregulation, foraging efficiency, tree stability, and interspecific competition influence selection of sleeping sites by proboscis monkeys (Nasalis larvatus) in Indonesian Borneo. We collected data on relative insect abundance, temperature, rainfall, food availability, group size, sleeping site location, and presence of other primates for 12 mo. Using formal model comparison and information criteria, we analyzed the relative importance of these ecological factors in determining one aspect of sleeping site location: distance from the river. Our models supported the avoidance of biting insects and the foraging efficiency hypotheses. Proboscis monkeys slept further inland on nights when the abundance of sandflies was high along the river, and when less food was available along the river. Many studies suggest that primates select sleeping trees and locations to reduce predation risk; our study indicates that additional factors may also be important in determining sleeping site selection.     

白马雪山自然保护区格花箐滇金丝猴夜宿地的季节性选择

2005年9月至2006年9月,在白马雪山自然保护区南端的格花箐,对一群(约250只)滇金丝猴的夜宿地选择与利用情况进行调查.整个调查历时13个月,确认研究群的夜宿点54个,共记录夜宿地的利用次数137次,提示研究群在其中一些地点多次夜宿.滇金丝猴夜宿地在平均海拔分布上存在明显的季节性差异:夏季猴群夜宿地的平均海拔为3 352 m,为一年中夜宿地分布最高的时期;春季猴群则多选择在低海拔地区夜宿,平均海拔在一年中最低(3 082 m).猴群夜宿地集中分布于3 200～3 400 m的海拔范围,随季节变化,不同海拔梯度上的夜宿地数量和利用频次差异明显.虽然猴群夜宿地主要位于针阔混交林中,但是不同季节猴群夜宿地植被的组成明显不同.猴群明显偏好在位于南坡面和西坡面的地点过夜,在夏季和秋季尚未发现北坡向的夜宿地.研究还表明,不同季节,猴群都会不同程度地在少数几个地点多次过夜,但大多数夜宿地在一年中仅利用一次.滇金丝猴为什么会对某些地点多次利用尚需进一步研究证实.     

Female‐biased sleeping aggregations of Amegilla florea urens (Hymenoptera: Apidae)

Although male bees and wasps aggregate in specific sites overnight, few studies have addressed the behaviors of female hymenopterans during the night. It is generally understood that they spend the night in a burrow or nest structure. We found female‐biased sleeping aggregations of Amegilla florea urens in populations on Iriomote Island. The sex ratio and number of sleeping individuals in the sex‐mixed aggregations changed daily. This species used dead branches as its main sleeping places, and the maximum number of individuals observed per place was 15. Females arrived at the aggregation place later and left it earlier in the morning than did males. Our result suggests that females used the sleeping place regularly but avoided a long stay with males. The use of the same sleeping place by the two sexes may be due to a limited number of sites suitable for sleeping in the forest.     

Sleeping site selection and presleep behavior in wild pigtailed macaques

Several factors are likely to control sleeping site selection and presleep behavior in nonhuman primates, including predation risk and location of food resources. We examined the effects of these factors on the sleeping behavior of northern pigtailed macaques (Macaca leonina). While following a troop living in the surroundings of the Visitor Center of Khao Yai National Park (Thailand), we recorded the physical characteristics and location of each sleeping site, tree, the individuals' place in the tree, posture, and behavior. We collected data for 154 nights between April 2009 and November 2010. The monkeys preferred tall sleeping trees (20.9 ± SD 4.9 m) and high sleeping places (15.8 ± SD 4.3 m), which may be an antipredator strategy. The choice of sleeping trees close to the last (146.7 ± SD 167.9 m) or to the first (150.4 ± SD 113.0 m) feeding tree of the day may save energy and decrease predation risk when monkeys are searching for food. Similarly, the choice of sleeping sites close to human settlements eases the access to human food during periods of fruit scarcity. Finally, the temporal pattern of use of sleeping sites, with a preference for four of the sleeping sites but few reuses during consecutive nights, may be a trade‐off between the need to have several sleeping sites (decreasing detection by predators and travel costs to feeding sites), and the need to sleep in well‐known sites (guaranteeing a faster escape in case of predator attack). Am. J. Primatol. 73:1222–1230, 2011. © 2011 Wiley Periodicals, Inc.     

Effect of piperine on pentobarbitone induced hypnosis in rats

Piperine (1-peperoyl piperidine), a major alkaloid isolated from Piper nigrum Linn, potentiated pentobarbitone sleeping time in dose dependant manner, with peak effect at 30 min. Blood and brain pentobarbitone levels were higher in piperine treated animals. Piperine treatment in rats, treated chronically with phenobarbitone, significantly potentiated pentobarbitone sleeping time, as compared to the controls. There was no alteration in barbital sodium sleeping time. It is possible that, piperine inhibits liver microsomal enzyme system and thereby potentiates the pentobarbitone sleeping time.     

Effect of cadmium on ethanol induced sleeping time in mice

The effect of cadmium on sleeping time induced by ethanol was studied in mice. When 0.25, 2.5 or 5.0 mg/kg of CdCl₂ was injected intraperitoneally (i.p.), the ethanol induced sleeping time was enhanced by 50 %, 100 % or 150 % from that of saline treated mice. The enhancement of ethanol induced sleeping time by cadmium was completely blocked by intracerebroventricular (i.vt.) pretreatment with CDTA, an agent that chelates cadmium ion. This indicates that the ethanol induced sleeping time was enhanced by a part of cadmium which passed through blood brain barrier after the i.p. injection.On the other hand, the ethanol induced sleeping time was also increased by 50 % with i.vt. injection of L-serotonin but not altered with L-dopamine or L-norepinephrine. In addition to this, i.vt. injection of L-serotonin plus L-norepinephrine enhanced by 170 % the ethanol induced sleeping time. Furthermore, the enhancement of ethanol induced sleeping time by cadmium was potentiated by i.vt. treatment of L-serotonin or L-norepinephrine but not by L-dopamine. These results suggest that the enhancement of ethanol induced sleeping time by cadmium may be caused by an increase in L-serotonin levels or both L-serotonin and L-norepinephrine levels but not by L-dopamine levels in brain of mouse.     

Spider monkey sleeping sites: Use and availability

The behavior of spider monkeys (Ateles geoffroyi) at sleeping sites and the characteristics of these sites were studied in Santa Rosa National Park, Costa Rica. The spider monkeys tended to congregate just prior to dusk at a number of sleeping sites which were repeatedly used (81.6%), but occasionally they slept in trees which were only used once (18.4%). All of the regularly used sleeping trees were not used concurrently, but rather, there was a rotation between sites. In general, males were not encountered at regularly used sleeping sites as often as other age/sex classes, and when they were in all male subgroups, they did not sleep in repeatedly used sites. The trees used as regular sleeping sites tended to be large, but such trees were common in the group's home range. The size of the subgroups attending repeatedly used sleeping trees was large when food was abundant and small when food was scarce. It is suggested that this relationship reflects that the costs of travelling to the sleeping site would be more easily recovered when food was abundant than when food was scarce.     

Sleeping habits of tamarins, Saguinus mystax and Saguinus fuscicollis (Mammalia; Primates; Callitrichidae), in north-eastern Peru

The sleeping habits of moustached tamarins, Saguinus mystax , and saddle-back tamarins, Saguinus fuscicollis , were studied in northeastern Peru. Five types of sleeping sites were distinguished: 1) Jessenia bataua palms; 2) tree hollows; 3) dense tangles of vegetation; 4) crotches; 5) open horizontal branches. Both tamarin species used Jesseniu-palms most frequently. Tree hollows ranked second in the saddle-back tamarins, but were never used by moustached tamarins. Sleeping sites of moustached tamarins were located significantly higher than those of saddle-back tamarins. Jessenia -palms used by moustached tamarins were significantly higher than palms from a random transect sample, but this was not the case for Jessenia -palms used by saddle-back tamarins. For both species, concealment seems to be more important than height above ground. The maximum number of subsequent nights spent in the same sleeping site was two in moustached tamarins and six in saddle-back tamarins. The two tamarin species did not compete for sleeping sites. While the general pattern of sleeping site selection conforms to hypotheses predicting safety from predators as a major factor, differences between the two tamarin species reflect general niche differences between them. Most sleeping sites are located in exclusively used parts of the home range. Moustached tamarins generally use sleeping sites that are close to the last feeding site of the afternoon. The distance between simultaneously used sleeping sites of moustached and saddle-back tamarins are generally close together, which helps to minimize time spent out of interspecific association.     

Species-specific usage of sleeping sites in two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar

We investigated the sleeping site ecology of two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar during the second half of the dry season with respect to the type, quality, and usage pattern of the sleeping sites, as well as to social sleeping habits and response to potential threats. The type and quality of the sleeping sites differed between the two species. M. murinus used protected wooden shelters (tree holes) more frequently than M. ravelobensis, and M. ravelobensis used a broader variety of less protected sites (e.g., branches, lianas, and leaves) than M. murinus. Whereas male M. murinus usually slept alone, and female M. murinus mostly slept in groups, both sexes of M. ravelobensis slept in mixed-sex sleeping groups. M. murinus relied on crypsis in their sleeping sites, whereas M. ravelobensis regularly showed a flight response to the approach of an observer. This behavioral difference could indicate an adaptation to a higher predation risk in less protected sleeping sites. Whereas female M. murinus showed a high site fidelity, male M. murinus and both sexes of M. ravelobensis frequently changed their sleeping sites, which may also be interpreted as an antipredator strategy. The results are discussed with respect to three possible ecological explanations: interspecies competition, restricted resource availability, and niche differentiation. The latter is the most likely explanation for these interspecific differences.     

Sleeping Sites and Latrines of Spider Monkeys in Continuous and Fragmented Rainforests: Implications for Seed Dispersal and Forest Regeneration

Spider monkeys (Ateles geoffroyi) use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively). Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure) of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations typical of the southeastern Mexican rainforest, such as Terminalia-Dialium, and Brosimum-Dialium.