Use Of Sleeping Sites Research Articles

Predator avoidance and food patch proximity influence sleeping site use of Assamese macaques in a limestone forest of Southwest Guangxi, China

AbstractObjectivesWe investigated the sleeping site use of one group of Assamese macaques in Southwest Guangxi, China. We examined their behavioral adaptation to limestone forests by evaluating hypotheses of predator avoidance, food proximity, and range or resource defense.Materials and MethodsWe recorded the locations of sleeping sites on a topographic map using a grid cell method and mapped the use of foraging patches within the home range.ResultsAssamese macaques used 19 different sleeping sites, mainly located on cliffs. They rapidly entered sleeping sites and then remained silent. They preferred three sites but never used them for more than four consecutive nights. Sleeping site use was positively correlated with the number of surrounding foraging patches, but the distances between sleeping sites and the last/first feeding areas (84.16 ± 41.26 and 94.88 ± 45.83 m, respectively) were not affected by seasonal fluctuations in fruit availability; these distances were longer than those predicted under a multiple central place foraging (MCPF) strategy but shorter than those predicted under a central place foraging (CPF) strategy. The observed distances between the sleeping sites and the first feeding areas in the rainy season were similar to the predicted distances of an MCPF strategy. The macaques slept in peripheral parts of their home range as expected, and there were no conflicts with neighboring groups.DiscussionSleeping site use was strongly affected by predator avoidance and proximity to food resources, but not by resource defense. The vertical distribution of sleeping sites on hills was not influenced by fruit availability. The macaques are closer to using an MCPF strategy to maximize food harvest efficiency, particularly in the rainy season. Assamese macaques' sleeping site use in limestone forests supports the hypotheses of predator avoidance and food proximity.

Home range, sleeping site use, and band fissioning in hamadryas baboons: Improved estimates using GPS collars.

Variation in spatial and temporal distribution of resources drives animal movement patterns. Links between ecology and behavior are particularly salient for the multilevel society of hamadryas baboons, in which social units cleave and coalesce over time in response to ecological factors. Here, we used data from GPS collars to estimate home range size and assess temporal patterns of sleeping site use in a band of hamadryas baboons in Awash National Park, Ethiopia. We used GPS data derived from 2 to 3 collared baboons over three 8–12‐month collaring intervals to estimate annual and monthly home ranges using kernel density estimators (KDEs) and minimum convex polygons (MCPs). The 95% KDE home range was 64.11 km2 for Collaring Interval I (July 2015–March 2016), 85.52 km2 for Collaring Interval II (October 2016–October 2017), 76.43 km2 for Collaring Interval III (July 2018–May 2019), and 75.25 km2 across all three collaring intervals. MCP home ranges were 103.46 km2 for Collaring Interval I, 97.90 km2 for Collaring Interval II, 105.22 km2 for Collaring Interval III, and 129.33 km2 overall. Ninety‐five percent KDE home range sizes did not differ across months, nor correlate with temperature or precipitation, but monthly MCP home ranges increased with monthly precipitation. Our data also revealed a southward home range shift over time and seven previously unknown sleeping sites, three of which were used more often during the wet season. Band cohesion was highest during dry months and lowest during wet months, with fissioning occurring more frequently at higher temperatures. One pair of collared individuals from Collaring Interval III spent 95% of nights together, suggesting they were members of the same clan. Our results both suggest that previous studies have underestimated the home range size of hamadryas baboons and highlight the benefits of remote data collection.

Spider Monkeys Rule the Roost: Ateline Sleeping Sites Influence Rainforest Heterogeneity.

Simple SummarySpider monkeys are important dispersers of many hardwood trees that contribute greatly to the carbon sequestration of tropical forests. One way in which Spider monkeys influence tropical ecosystem structure and function is through the creation of visible terrestrial latrines beneath their “sleeping sites”—trees in which they frequently return to sleep. Spider monkey latrines are thought to create high quality resource patches for rainforest plants and other wildlife to exploit. We investigate this using camera traps placed in both the canopy and on the rainforest floor to determine which rainforest wildlife are attracted to the latrines beneath the sleeping sites of spider monkeys. We also assess the tree species and dung beetles found within the latrines compared with other areas of the forest. Our evidence suggests that spider monkey roosting sites are a hub of activity for other rainforest wildlife, and act as germinating beds for many rainforest trees. If rainforests were to lose spider monkeys, from intensive hunting for example, many other rainforest wildlife species would be affected, and forests would therefore be made up of different tree communities than landscapes where spider monkeys exist.The sleeping site behavior of Ateline primates has been of interest since the 1980s, yet limited focus has been given to their influence upon other rainforest species. Here, we use a combination of arboreal and terrestrial camera traps, and dung beetle pitfall traps, to characterize spider monkey sleeping site use and quantify the impact of their associated latrines on terrestrial vertebrate and dung beetle activity. We also characterize the physical characteristics of the sleeping sites and the floristic and soil composition of latrines beneath them. Spider monkey activity at sleeping sites peaked at dawn and dusk and group composition varied by sex of the adults detected. The habitat-use of terrestrial fauna (vertebrates and dung beetles) differed between latrine sites and non-latrine controls, underpinned by species-specific changes in the relative abundance of several seed-dispersing species (such as paca and great curassow). Seedling density was higher in latrines than in non-latrine controls. Although most soil properties were similar between latrines and controls, potassium and manganese concentrations were different. These results suggest that spider monkey sleeping site fidelity leads to a hotspot of ecological activity in latrines and downstream impacts on rainforest floristic composition and diversity.

Burrow usage patterns and decision-making in meerkat groups

Abstract Choosing suitable sleeping sites is a common challenge faced by animals across a range of taxa, with important implications for the space usage patterns of individuals, groups, and ultimately populations. A range of factors may affect these decisions, including access to resources nearby, shelter from the elements, safety from predators, territorial defense, and protection of offspring. We investigated the factors driving patterns of sleeping site use in wild Kalahari meerkats (Suricata suricatta), a cooperatively breeding, territorial mongoose species that forages on scattered resources and makes use of multiple sleeping sites (burrows). We found that meerkat groups used some burrows much more often than others. In particular, large burrows near the center of the territory were used more often than small and peripheral burrows, and groups became even more biased toward central burrows when rearing pups. Meerkats also used their sleeping burrows in a nonrandom order. When they changed sleeping burrows, they moved disproportionately to nearby burrows but did not always select the closest burrow. Burrow decisions also reflected responses to short-term conditions: rates of switching burrows increased after encounters with predators and when resources were depleted, whereas group splits were associated with a reduced probability of switching. The group’s dominant female appeared to have disproportionate influence over burrow decisions, as groups were more likely to switch burrows when her foraging success was low. Our results link behavioral and movement ecology to show that a multitude of environmental and social factors shape daily group decisions of where to spend the night.

The role of sleeping sites in the predator-prey dynamics of leopards and olive baboons.

Predation is widely recognized as an important selective pressure on prey animals such as baboons (Papio spp.), which face high leopard (Panthera pardus) predation risk, particularly at night. Baboons regularly sleep on cliff faces and in trees at night, ostensibly to avoid such predators. Despite retreating to such "refuges," baboons are most often killed by leopards at or near their sleeping sites. Because of the challenges of studying nocturnal behavior and human-averse predators, few systematic data exist to reveal how leopard ranging near baboon sleeping sites influences baboons' selection of sites and behavior at those sites. To investigate leopard-baboon dynamics at sleeping sites we deployed GPS/VHF radio collars on six representatives of four baboon groups and four leopards during a 14-month field study in Kenya. We used locations recorded every 15 min to identify baboons' cliffside and riverine sleeping sites, the frequency and duration of leopard visits to these sites, and baboons' adjustments in site use after leopard visits. Collared leopards visited riverine sites more frequently than cliffside sites, whereas most baboon groups strongly preferred cliffside sites, suggesting that leopard visits were often due to factors other than baboon presence, and that baboons used cliffside sites to reduce their risk of leopard predation. Regardless of type, collared leopards remained near baboon-occupied sleeping sites longer than vacant ones, indicating interest in hunting baboons then. Baboons at riverine sites departed later on mornings after leopard visits. Baboon groups occasionally shared sleeping sites simultaneously, possibly reducing risk through dilution. However, they did not reduce risk by frequently changing sleeping sites, minimizing detection at sleeping sites, or after leopard visits, arriving earlier the next evening or moving to a different site. Future research should explore if baboons readily detect nocturnal leopard presence and if predation-related changes in sleeping site use have cascading ecological effects.

Getting better temporal and spatial ecology data for threatened species: using lightweight GPS devices for small primate monitoring in the northern Andes of Colombia.

The use of GPS telemetry has been a reliable research tool for the study of primate biology in recent years. Although in the past technological restrictions limited its use mainly to large primates, recent improvements in battery size make it possible to use this technology for small species. We used GPS devices for monitoring two adult white-footed tamarins (Saguinus leucopus) from a free-ranging group, and assessed its applicability for recording spatial and ecological data. GPS devices were operational for 66 and 85days, recording 221 positions (36.6% acquisition rate; 73% of which were highly accurate) and 3195 activity values for both individuals. Depending on the estimation method, we calculated the home range size for the group to be 19.4 and 22.9ha, which were within the range for the species in other localities. The animals were active each day for 11h, with high activity during the early morning. The monkeys showed a constant and alternate use of four sleeping sites with a limited reuse of the same site on consecutive nights. These daily activity and sleeping site use patterns are similar to those reported for other Saguinus species. Based on the kind and quality of the data recorded, we consider GPS telemetry to be an efficient and advantageous method for tracking and obtaining ecological information from S. leucopus. In comparison to other data collection methods, GPS telemetry required fewer personnel and less time commitment to record data without compromising the accuracy of the spatial and activity information we obtained.

Food resources, distribution and seasonal variations in ranging in lion-tailed macaques, Macaca silenus in the Western Ghats, India.

The distribution and availability of food was examined to see how it influenced ranging patterns and sleeping site selection in a group of lion-tailed macaques. The home range and core area were 130.48 ha (95% kernel) and 26.68 ha (50% kernel) respectively. The lion-tailed macaques had a longer day range, had a greater number of sleeping sites and used more core areas in the summer as compared to the monsoon and the post-monsoon seasons. The ranging patterns and sleeping site use were influenced by the major food resources used in a particular season. The ranging was mainly influenced by Artocarpus heterophyllus in monsoon, Cullenia exarillata and Toona ciliata in post- monsoon, and Artocarpus heterophyllus and Ficus amplissima in summer. The distribution of these four plant species is, therefore, critical to ranging, and thus to conservation of the lion-tailed macaque.

Sleeping site use of the white-headed langur Trachypithecus leucocephalus: The role of predation risk, territorial defense, and proximity to feeding sites

Abstract We collected data on sleeping site use from two groups of white-headed langurs Trachypithecus leucocephalus living in Fusui Nature Reserve, China between August 2007 and July 2008. This information was used to test several hypotheses regarding ultimate causes of sleeping site use in this primate. White-headed langurs slept either in caves (17 sites) or on a cliff ledge (one site). They used all sleeping sites repeatedly, and reused some of them on consecutive nights; three nights was the longest consecutive use of any one sleep site. We suggest that langurs use sleeping sites to make approach and attack by predators difficult, and to increase their own familiarity with a location so as to improve chances for escape. Langurs’ cryptic behaviors with an increased level of vigilance before entering sleeping sites may also help in decreasing the possibility of detection by predators. Group 1 spent more sleeping nights in the central area of their territory than expected; in contrast, group 2 spent more sleeping nights in the periphery of their territory, which overlaps with that of another groups, than expected. 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. These results suggest that territory defense and food access may play an important role in sleeping site use of white-headed langurs.

Sleeping Site Use by Trachypithecus francoisi at Nonggang Nature Reserve, China

We collected data on sleeping site use of the Francois’ 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 Francois’ 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.

Long‐term patterns of sleeping site use in wild saddleback (Saguinus fuscicollis) and mustached tamarins (S. mystax): Effects of foraging, thermoregulation, predation, and resource defense constraints

Sleeping sites are an important aspect of an animal's ecology given the length of time that they spend in them. The sleep ecology of wild saddleback and mustached tamarins is examined using a long-term data set covering three mixed-species troops and 1,300+ tamarin nights. Seasonal changes in photoperiod accounted for a significant amount of variation in sleeping site entry and exit times. Time of exit was more closely correlated with sunrise than time of entry was with sunset. Both species entered their sleeping sites when light levels were significantly higher than when they left them in the morning. Troops of both species used >80 individual sites, the majority being used once. Mustached tamarins never used the same site for more than two consecutive nights, but saddlebacks reused the same site for up to four consecutive nights. Mustached tamarins slept at significantly greater heights than saddleback tamarins. There were consistent interspecific differences in the types of sites used. Neither the presence of infants, season, nor rainfall affected the types or heights of sites chosen. Sleeping sites were located in the central area of exclusive use more often than expected, and their position with respect to fruiting trees indicated a strategy closer to that of a multiple central place forager than a central place forager. These findings are discussed in light of species ecology, with particular reference to predation risk, which is indicated as the major factor influencing the pattern of sleeping site use in these species.

Tree and forest characteristics influence sleeping site choice by golden lion tamarins

Lion tamarin monkeys are among a small number of primates that repeatedly use a few tree holes for the majority of their sleeping sites. To better understand why lion tamarins rely on tree holes as sleeping sites, we compared the physical characteristics of frequently used sleeping sites, infrequently used sleeping sites, and randomly selected forest locations at multiple spatial scales. From 1990 to 2004, we recorded 5,235 occurrences of sleeping site use by 10 groups of golden lion tamarins (Leontopithecus rosalia) in Poço das Antas Reserve, Rio de Janeiro State, Brazil. Of those, 63.6% were tree holes. Bamboo accounted for an additional 17.5% of observations. Frequently used tree holes were more likely to be found in living trees and their entrances were at lower canopy heights than infrequently used tree holes. We also found that frequently used sleeping sites, in comparison to random sites, were more likely to be found on hillsides, be close to other large trees, have a lower percent of canopy cover, and have larger diameter at breast height. Topography and small-scale variables were more accurate than were habitat-level classifications in predicting frequently used sleeping sites. There are ample tree holes available to these lion tamarins but few preferred sites to which they return repeatedly. The lion tamarins find these preferred sites wherever they occur including in mature forest and in relics of older forest embedded in a matrix of secondary forest.

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.

Characteristics of night‐time sleeping places selected by golden monkeys (Rhinopithecus bieti) in the Samage Forest, Baima Snow Mountain Nature Reserve, China

We examined the criteria for sleeping place selection in a social band of Rhinopithecus bieti (black-and-white snub-nosed or golden monkeys) living in the mountainous Samage Forest, Baima Snow Mountain Nature Reserve, Yunnan, China. We performed principal component analysis and found that slope aspect, tree height and trunk diameter were likely key variables influencing selection of sleeping places. Sleeping sites were preferentially located in mixed deciduous/conifer forest. The monkeys slept exclusively in evergreen trees, of which 82% were conifers (mostly Picea likiangensis and Tsuga dumosa) and 18% evergreen oaks (Cyclobalanopsis oxyodon and Quercus spp.). Sleeping trees were tall (mean 30.5 m), had high boles (mean 18.4 m), large diameters (mean 62.6 cm) and large crown areas (mean 57.9 m(2) ). A comparative analysis of phytological and architectural features between trees in "sleeping site plots" (n= 18) and trees in "non-sleeping-site plots" (n= 66) revealed that diameter, crown surface area and tree height were significantly (P < 0.01) larger in the former compared with the latter. All investigated roosting sites were situated on steep mountain slopes. Valleys and mountain ridges were avoided. We also detected re-use of roosting sites on several occasions, but not on consecutive nights. It is most likely that a mix of factors (stability of trees, access to food, unit cohesion, monitoring potential) explains the pattern of sleeping site preference, but predation at night seems to be only slightly important. Climate appears to have a profound influence on patterns of sleeping site selection in the monkeys' harsh temperate habitat. This is demonstrated by the monkeys' preference for mixed forest at medium elevations over montane fir forest at high elevations and slopes instead of ridges, with reduced exposure to wind and precipitation inherent in the former. We also emphasize the possibly substantial role that non-environmental factors (the nature of social organization and socio-behavioral strategies) play in determining sleeping site use in R. bieti and other primates.

So near and yet so far: territorial pairs but low cohesion between pair partners in a nocturnal lemur, Phaner furcifer

Among pair-living species, which represent a simple form of gregariousness, the degree of cohesion appears to be highly variable, but the mechanisms responsible for the maintenance of cohesiveness have been poorly studied. We present data from long-term behavioural observations of eight pairs of fork-marked lemurs, including year-round data on their sleeping site use and spatial data from simultaneous focal follows of both pair partners, that characterize its social organization as ‘dispersed pairs’. Although pairs were stable over several years, territories of pair partners overlapped almost perfectly and interactions between them were frequent, the cohesiveness of pairs was extremely low. High rates of conflict relative to frequencies of affiliative interactions indicated that avoidance of the pair partner is the key mechanism responsible for the observed pattern of space use. The repeated use of the same predictable food resources during the night, frequent conflicts over food and patterns of vocal communication imply that avoidance of direct feeding competition, together with incomplete knowledge about the pair partner's position, lead to the observed low cohesiveness. The freedom to forage solitarily and the associated lack of information about the pair partner's position found in fork-marked lemurs are in contrast to most group-living species and qualify dispersed pairs as a focus for future studies of models on animal movement decisions. Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

Sleeping site preferences in tufted capuchin monkeys (Cebus apella nigritus)

The characteristics and availability of the sleeping sites used by a group of 27 tufted capuchin monkeys (Cebus apella nigritus) were studied during 17 months at the Iguazú National Park, Argentina. We tested different hypotheses regarding possible ultimate causes of sleeping-site selection. Most sleeping sites were located in areas of tall, mature forest. Of the 34 sleeping sites the monkeys used during 203 nights, five were more frequently used than the others (more than 20 times each, constituting 67% of the nights). Four species of tree (Peltophorum dubium, Parapiptadenia rigida, Copaifera langsdorfii and Cordia trichotoma) were the most frequently used. They constituted 82% of all the trees used, though they represent only 12% of the trees within the monkeys' home range which had a diameter at breast height (DBH) > 48.16 cm (1 SD below the mean DBH of sleeping trees). The sleeping trees share a set of characteristics not found in other trees: they are tall emergent (mean height ± SD = 31.1± 5.2 m) with large DBH (78.5 ± 30.3 cm), they have large crown diameter (14± 5.5 m), and they have many horizontal branches and forks. Adult females usually slept with their kin and infants, while peripheral adult males sometimes slept alone in nearby trees. We reject parasite avoidance as an adaptive explanation for the pattern of sleeping site use. Our results and those from other studies suggest that predation avoidance is a predominant factor driving sleeping site preferences. The patterns of aggregation at night and the preference for trees with low probability of shedding branches suggest that social preferences and safety from falling during windy nights may also affect sleeping tree selection. The importance of other factors, such as seeking comfort and maintaining group cohesion, was not supported by our results. Other capuchin populations show different sleeping habits which can be explained by differences in forest structure and by demographic differences. Am. J. Primatol. 50:257–274, 2000. © 2000 Wiley-Liss, Inc.