Showing papers in "Folia Primatologica in 2015"
TL;DR: It was found that all 100 videos showed at least 1 condition known as negative for lorises, indicating absence of the necessary freedom, and the public were more likely to like videos where a slow loris was kept in the light or displayed signs of stress.
Abstract: Videos, memes and images of pet slow lorises have become increasingly popular on the Internet. Although some video sites allow viewers to tag material as 'animal cruelty', no site has yet acknowledged the presence of cruelty in slow loris videos. We examined 100 online videos to assess whether they violated the 'five freedoms' of animal welfare and whether presence or absence of these conditions contributed to the number of thumbs up and views received by the videos. We found that all 100 videos showed at least 1 condition known as negative for lorises, indicating absence of the necessary freedom; 4% showed only 1 condition, but in nearly one third (31.3%) all 5 chosen criteria were present, including human contact (57%), daylight (87%), signs of stress/ill health (53%), unnatural environment (91%) and isolation from conspecifics (77%). The public were more likely to like videos where a slow loris was kept in the light or displayed signs of stress. Recent work on primates has shown that imagery of primates in a human context can cause viewers to perceive them as less threatened. Prevalence of a positive public opinion of such videos is a real threat towards awareness of the conservation crisis faced by slow lorises.
55 citations
TL;DR: It is predicted that changes in behaviour should increase with risk posed by a perceived predator, and the concept of ‘pseudopredators' (harmless species whose appearance is sufficiently similar to that of predators to elicit antipredator responses) is introduced.
Abstract: Predation is often considered to be a prime driver in primate evolution, but, as predation is rarely observed in nature, little is known of primate antipredator responses. Time-limited primates should be highly discerning when responding to predators, since time spent in vigilance and avoidance behaviour may supplant other activities. We present data from two independent studies describing and quantifying the frequency, nature and duration of predator-linked behaviours in 2 high-canopy primates, Ateles belzebuth and Cacajao ouakary. We introduce the concept of 'pseudopredators' (harmless species whose appearance is sufficiently similar to that of predators to elicit antipredator responses) and predict that changes in behaviour should increase with risk posed by a perceived predator. We studied primate group encounters with non-primate vertebrates across 14 (Ateles) and 19 (Cacajao) months in 2 undisturbed Amazonian forests. Although preliminary, data on both primates revealed that they distinguished the potential predation capacities of other species, as predicted. They appeared to differentiate predators from non-predators and distinguished when potential predators were not an immediate threat, although they reacted erroneously to pseudopredators, on average in about 20% of the responses given toward other vertebrates. Reacting to pseudopredators would be interesting since, in predation, one error can be fatal to the prey.
55 citations
TL;DR: The data in this paper represent the first evidence that this species communicates in the ultrasonic range, and characterizes the types of ultrasonic vocalizations by spectral tarsiers, Tarsius spectrum.
Abstract: Although the vocalizations of spectral tarsiers have been studied for over 3 decades by numerous primatologists, the data in this paper represent the first evidence that this species communicates in the ultrasonic range. In addition, this paper characterizes the types of ultrasonic vocalizations by spectral tarsiers, Tarsius spectrum. Data were collected at Tangkoko Nature Reserve in Sulawesi, Indonesia, from January through April 2013. Recordings were made on a Wildlife Acoustics Ultrasonic Song Meter BAT2 from 10 groups of varying sizes and compositions. The ultrasonic recorder was placed at the base of the group's sleeping tree and recorded from 5.00 to 7.00 h using an omnidirectional microphone. The ultrasonic vocalizations fell into 5 main categories: chirps, twitters, choruses, doubles and whistles. Chirps were the most frequent ultrasonic vocalizations, followed by twitters, choruses, doubles and then whistles. While chirps, twitters and choruses extended from the audible to the ultrasonic range, the doubles and whistles were pure ultrasound. Currently, the function of these ultrasonic vocalizations is not yet clear and requires additional research.
47 citations
TL;DR: A survey of the natural variation of the gut microbiome in 2 wild lemur species, Lemur catta and Propithecus verreauxi, found abundant variation between individuals and from the dry to the wet season.
Abstract: Mammalian gut microbes are invaluable to the host's metabolism, but few researchers have examined gut microbial dynamics under natural conditions in wild mammals. This study aims to help fill this knowledge gap with a survey of the natural variation of the gut microbiome in 2 wild lemur species, Lemur catta and Propithecus verreauxi. The wild L. catta were also compared to a captive population to discern the effect of habitat within a species. Gut microbial DNA was extracted from fecal samples collected in Madagascar and the Vienna Zoo and sequenced. The wild and captive L. catta had distinct microbial communities, likely due to differences in diet and development between their populations. The wild L. catta and P. verreauxi also had distinct gut microbiomes, due to a change in microbial abundance, not composition. Within each lemur species, there was abundant variation between individuals and from the dry to the wet season. The intraspecific and temporal microbial variation requires more investigation, with changes in diet a likely contributor.
44 citations
TL;DR: The social tolerance of bonobos is measured in an experiment recently validated with chimpanzees to allow for a comparative assessment of group-level tolerance, and it is found that the bonobo group studied here exhibited lower social tolerance on average than chimpanzees in this paradigm.
Abstract: Social tolerance is a core aspect of primate social relationships with implications for the evolution of cooperation, prosociality and social learning. We measured the social tolerance of bonobos in an experiment recently validated with chimpanzees to allow for a comparative assessment of group-level tolerance, and found that the bonobo group studied here exhibited lower social tolerance on average than chimpanzees in this paradigm. Furthermore, following the Relational Model of de Waal, we investigated whether bonobos responded to an increased potential for social conflict with tolerance, conflict avoidance or conflict escalation, and found that only behaviours indicative of conflict escalation differed across conditions. Taken together, these findings contribute to the current debate over the level of social tolerance of bonobos and lend support to the position that the social tolerance of bonobos may not be notably high compared with other primates.
33 citations
TL;DR: The model aids in the identification of suitable areas for the reintroduction program of H. leuconedys that is planned by the Gibbon Conservation Breeding Centre, Biological Park, Itanagar, Arunachal Pradesh, India.
Abstract: The eastern hoolock gibbon, Hoolock leuconedys, is categorized as Vulnerable on the IUCN Red List and assessed as a Schedule I species of the Wildlife (Protection) Act of 1972 in India. We predict the potential habitat of H. leuconedys in the state of Arunachal Pradesh, India, using the Maximum Entropy (MaxEnt) distribution modelling algorithm. The model was developed using 90 known localities of H. leuconedys in the state. Nineteen environmental parameters along with 12 normalized difference vegetation index (NDVI) layers, elevation and land use and land cover (LULC) were used in the modelling. Amongst the environmental input variables, the precipitation of the coldest quarter (BIO 19) had the highest contribution to the model (26.03%) and the twelve NDVI layers collectively contributed 60.91%. Two districts, Lower Dibang Valley and Lohit, which are known to contain H. leuconedys, occupied 64.75% of the predicted distribution area of the species. Thus, we aid in the identification of suitable areas for the reintroduction program of H. leuconedys that is planned by the Gibbon Conservation Breeding Centre, Biological Park, Itanagar, Arunachal Pradesh, India.
19 citations
TL;DR: The attempt to explore how nonlocomotor behavior covaries with skeletal morphology should provide for more informed interpretations of the primate fossil record is explored.
Abstract: Most investigations of primate scapular morphology use differences in locomotion to explain variation; less is known about how scapular geometry covaries with nonlocomotor behavior. We examined forelimb use during foraging in 4 cercopithecids ranging throughout the Ivory Coast's Tai Forest. During 5-min feeding bouts, we recorded the frequency individuals of Piliocolobus badius, Colobus polykomos, Cercocebus atys and Cercopithecus diana performed 5 forelimb behaviors involved in the acquisition and introduction of food to the oral cavity. Scapulae from these populations were examined to determine whether differences in forelimb use were reflected in features known to correspond with varying degrees of arm flexion, abduction and elevation. Our results reveal that the species differ markedly in forelimb use and that these differences are interpretable via their scapular morphology. For example, P. badius engages in more frequent flexion, abduction and elevation of the arm above the head relative to C. polykomos, and red colobus scapulae are longer craniocaudally and have larger, more cranially directed supraspinous fossae than those of closely related black-and-white colobus. Our attempt to explore how nonlocomotor behavior covaries with skeletal morphology should provide for more informed interpretations of the primate fossil record.
15 citations
TL;DR: This study provides the first detailed activity budgets subdivided by age-sex class of Yunnan snub-nosed monkeys, based on observations of the largest habituated group of R. bieti at Xiangguqing in Baimaxueshan Nature Reserve.
Abstract: The activity budgets of primates reflect their survival strategy. Despite existing data on the activity budgets of Yunnan snub-nosed monkeys (Rhinopithecus bieti), little is known about how activity budgets vary between age-sex classes. This study provides the first detailed activity budgets subdivided by age-sex class, based on observations of the largest habituated group of R. bieti at Xiangguqing in Baimaxueshan Nature Reserve. This study was conducted from June 2008 to May 2009. We found that adult females spent more time feeding (44.8%) than adult males (39.5%), juveniles (39.1%) and infants (14.2%). Females allocated significantly more time to feeding than to any other activity. Adult males allocated more time to miscellaneous activities (12.5%) than adult females (3.8%). Juveniles allocated less time to grooming than adults. Infants were being groomed 6.9% of the time, the highest proportion among all age-sex classes. Adults spent more time feeding, while immature individuals allocated more time to moving and other activities. There are several reasons why activity budgets can vary by age-sex class: (1) differential reproductive investment between males and females; (2) developmental differences among the age categories, and (3) social relationships between members of different age-sex classes, particularly dominance. These variations in activity budgets among the different age-sex classes may become a selective pressure in this species.
14 citations
TL;DR: A mixed longitudinal sample of observations on feeding and foraging behaviour from ring-tailed lemurs at the Bezà Mahafaly Special Reserve, Madagascar shows that the gregarious strepsirrhines may show foraging patterns similar to those implicated in the evolution of a life history where long juvenile periods are advantageous.
Abstract: The extended primate juvenile period has been linked to interactions between feeding ecology and sociality. However, accumulating field data on juvenile primates suggest variation in the linkages between foraging efficiency, group foraging and social behaviour. In many non-human primates, juvenile ability (strength, coordination and motor skills) does not limit foraging success. If predicted limitations in feeding are not found in juvenile monkeys, it is possible that the gregarious strepsirrhines may show foraging patterns similar to those implicated in the evolution of a life history where long juvenile periods are advantageous. To test these behavioural predictions, I present a mixed longitudinal sample of observations on feeding and foraging behaviour from ring-tailed lemurs (Lemur catta) at the Beza Mahafaly Special Reserve, Madagascar. Like several platyrrhine species, close proximity during foraging, low feeding efficiency and low dietary diversity are not typical of ring-tailed lemurs. The lack of ecological trade-offs in these species may indicate stronger common roles of sociality and social complexity in structuring the elongation of the primate juvenile period.
14 citations
TL;DR: Comparing plant food selection and properties for ring-tailed lemurs in the spiny and gallery forests over the synchronized lactation period that includes both the dry and wet seasons finds no significant habitat-specific differences in the type of plant part consumed per month.
Abstract: Although Lemur catta persists in many habitat types in southern Madagascar, its ecology has been primarily studied within gallery forests. We compare plant food selection and properties for ring-tailed lemurs in the spiny and gallery forests over the synchronized lactation period (September to March) that includes both the dry and wet seasons. We found no significant habitat-specific differences in the type of plant part consumed per month (i.e. flower, fruit, leaf) or between the intake of soluble carbohydrates. However, the presence and use of Tamarindus indica plants appear to elevate protein and fiber intake in the gallery forest lemurs' diets. Protein is especially important for reproductive females who incur the added metabolic costs associated with lactation; however, fiber can disrupt protein digestion. Future work should continue to investigate how variations of protein and fiber affect ring-tailed lemur dietary choice and nutrient acquisition.
12 citations
TL;DR: This research will help promote the survival and conservation of the Sichuan snub-nosed monkey in the Qinling Mountains and help understand the influence of human activities within the habitat of R. roxellana.
Abstract: Due to their rich animal diversity and the presence of rare and endemic species, the Qinling Mountains are listed as a significant global biodiversity area. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) has been distributed in this area since the Middle Pleistocene. Due to the gradual encroachment of humans into their habitat, both the distribution range and population sizes of R. roxellana have significantly decreased. Based on literature research as well as field and questionnaires, we investigated the influence of human activities on R. roxellana distribution in the Qinling Mountains. Human activity within the habitat of R. roxellana began in the Stone and Bronze Ages, though initially it had no significant influence on its populations. When China entered the Iron Age, however, different historical and social periods had a considerable impact on R. roxellana distribution. Although national and provincial level governments introduced strict protection policies with the establishment of the People's Republic of China in 1949, human activities continued to influence R. roxellana distribution. Since the launch of the Natural Forest Protection Project across the Qinling Mountains in 1999, the quality of R. roxellana habitat has shown marked improvement. This research will help promote the survival and conservation of the Sichuan snub-nosed monkey in the Qinling Mountains.
TL;DR: Compared to other socially monogamous primates, sakis appear to have a more variable social system whereby additional males can join established groups and form relationships with putatively unrelated males.
Abstract: Saki monkeys live in socially monogamous groups and in groups containing more than one same-sex adult. As part of a 10-year study of equatorial sakis (Pithecia aequatorialis) in Ecuador, we documented the immigration of a second adult male into a group containing a resident male-female pair that had associated with one another for seven years and the resident female's two daughters. In the first month after immigration, the resident male spent more time closer to and grooming his putative adult daughter than the resident female, and the two males were seen performing a cooperative territorial display. After two months, the resident male interacted more with the resident female than with his putative adult daughter, while that daughter interacted more with the immigrant male and copulated with him. After three months, the males left the group together and associated with an unfamiliar female, leaving the resident females and a neonate behind. The resident male then paired with a new female, while the immigrant male joined another group, again as a second male. Compared to other socially monogamous primates, sakis appear to have a more variable social system whereby additional males can join established groups and form relationships with putatively unrelated males.
TL;DR: It is shown that male L. catta consistently participated in group-level antipredator vocalization usage in high-risk locations, and is found to support 2 hypotheses for predator confusion, group maintenance, and predation risk allocation.
Abstract: The ring-tailed lemur (Lemur catta) is a group-living strepsirrhine primate endemic to Madagascar that faces considerable predation pressure from aerial and terrestrial predators. This species engages in mobbing and vigilance behavior in response to predators, and has referential alarm vocalizations. Because L. catta is female dominant, less is known about the alarm calls of males. We tested 3 hypotheses for male antipredator vocalization behavior on L. catta at the Beza Mahafaly Special Reserve in Madagascar: the predator confusion, group maintenance, and predation risk allocation hypotheses. We found support for 2 hypotheses. When a male L. catta made an antipredator call, other group members vocalized in response. Dominant males did not make alarm calls at higher rates than subordinate males. Predators were more abundant on the western side of Parcel 1, but an even greater number of antipredator vocalizations occurred in this area than predator abundance warranted. We show that male L. catta consistently participated in group-level antipredator vocalization usage in high-risk locations. Although female L. catta are known to hold the primary role in group defense, male L. catta are also key participants in group-wide behaviors that may confuse or drive away predators.
TL;DR: It is suggested that most females can maintain reproductive performance in their later life and that there is no evidence for a postreproductive lifespan in this species.
Abstract: The lifespan and age-specific fecundity of female ring-tailed lemurs (Lemur catta) were estimated from a 24-year longitudinal dataset based on individual identification at Berenty Reserve, Madagascar. The mean lifespan of females in 10-year (1989-1998) birth cohorts was 4.9 ± 4.9 years (n = 77), and the longest recorded lifespan in the population was 20 years. The mortality rate of adult females increased to ≥20% at 10-11 years old and reached 33-50% at 12-15 years old. Although the birth rate of old females (12-17 years old) was 72.0%, slightly lower than that of prime adult females (4-11 years old), i.e. 80.2%, no significant difference was found between them. Half of the females who reached the age of 12 years gave birth in the last year of their life. The oldest mother to give birth was 17 years old. These results suggest that most females can maintain reproductive performance in their later life and that there is no evidence for a postreproductive lifespan in this species.
TL;DR: Reviewing studies investigating cognitive abilities in the technical and social domain of ring-tailed lemur cognition finds that in several other aspects of social cognition, ring- tails' cognitive abilities are equal to those of other lemurs.
Abstract: In order to better understand the evolution of cognitive abilities in primates, information on cognitive traits of the most basal living primates can provide important comparative baseline data. Compared to haplorhine primates, lemurs have relatively smaller brains and reduced abilities to solve problems in the technical and social domain. However, recent studies have suggested that some cognitive abilities of lemurs are qualitatively equal to those of haplorhines. Here, we review studies investigating cognitive abilities in the technical and social domain of ring-tailed lemur cognition. In the physical domain, ring-tailed lemurs exhibit similar qualitative cognitive skills as other lemurs but also haplorhine primates. In the social domain, ring-tailed lemurs appear to be more skilled in visual perspective taking than other lemurs. Compared to other lemurs, they also have highly elaborated communicative skills. Moreover, within-group coalitions have been observed in female ring-tailed lemurs during rare events of female evictions but not in other lemur species. However, in several other aspects of social cognition, such as reconciliation and social learning, ring-tailed lemurs' cognitive abilities are equal to those of other lemurs. Thus, additional systematic comparative studies in physical and social cognition are required for a more comprehensive understanding of the processes of cognitive evolution among primates.
TL;DR: Orangutans should be provisioned with seasonally appropriate, high quality materials suitable for construction of sleeping platforms to increase sleep quality and improve animal health and welfare.
Abstract: The nightly construction of a ‘nest' or sleeping platform is a behavior that has been observed in every wild great ape population studied, yet in captivity, few analyses have been performed on sleep related behavior. Here, we report on such behavior in three female and two male captive orangutans (Pongo spp.), in a natural light setting, at the Indianapolis Zoo. Behavioral samples were generated, using infrared cameras for a total of 47 nights (136.25 h), in summer (n = 25) and winter (n = 22) periods. To characterize sleep behaviors, we used all-occurrence sampling to generate platform construction episodes (n = 217). Orangutans used a total of 2.4 (SD = 1.2) techniques and 7.5 (SD = 6.3) actions to construct a sleeping platform; they spent 10.1 min (SD - 9.9 min) making the platform and showed a 77% preference for ground (vs. elevated) sleep sites. Comparisons between summer and winter platform construction showed winter start times (17:12 h) to be significantly earlier and longer in duration than summer start times (17:56 h). Orangutans should be provisioned with seasonally appropriate, high quality materials suitable for construction of sleeping platforms to increase sleep quality and improve animal health and welfare.
TL;DR: Analysis of dispersal patterns in Lemur catta populations in southwestern Madagascar demonstrates that dispersal partners consist of same-sexed kin for L. catta males and females, highlighting the importance of kin selection.
Abstract: Lemur catta has traditionally been considered a species with male-biased dispersal; however, occasional female dispersal occurs. Using molecular data, we evaluated dispersal patterns in 2 L. catta populations in southwestern Madagascar: Tsimanampesotse National Park (TNP) and Beza Mahafaly Special Reserve (BMSR). We also investigated the genetic differentiation between the populations and dispersal partner relatedness. Results showed minor genetic differentiation between the populations (ϴ(ST) = 0.039), which may indicate gene flow historically occurring in this region, made possible by the presence of L. catta groups between the sites. Different patterns of sex-biased dispersal were found between the sites using corrected assignment indices: male-biased dispersal in TNP, and a lack of sex-biased dispersal in BMSR. Observational evidence of female dispersal in BMSR supports these results and may imply intense female resource competition in and around BMSR, because small groups of 2-3 females have been observed dispersing within BMSR and entering the reserve from outside. These dispersing groups largely consisted of mothers transferring with daughters, although we have an aunt-niece pair transferring together. Genetic data suggest that males also transfer with relatives. Our data demonstrate that dispersal partners consist of same-sexed kin for L. catta males and females, highlighting the importance of kin selection.
TL;DR: Qualitative data on how the social network and sex of infants influence allomothering behaviour among wild Formosan macaques, Macaca cyclopis, supports 2 major hypotheses, i.e. those of reciprocity and alliance formation and neither could account for the observed occurrences of unrelated infant handling by dominant females.
Abstract: In this paper, we present quantitative data on how the social network and sex of infants influence allomothering behaviour among wild Formosan macaques, Macaca cyclopis. Using long-term field data collected from the Mount Longevity study site in Kaohsiung (Taiwan), we have tested relevant hypotheses incorporating data on age, rank and reproductive state of infant handlers, and the relationship between handlers and infants. The results support 2 major hypotheses, i.e. those of reciprocity and alliance formation. Nevertheless, neither could account for the observed occurrences of unrelated infant handling by dominant females.
TL;DR: The population density of the critically endangered Callicebus oenanthe in the Ojos de Agua Conservation Concession, a dry forest area in the department of San Martin, Peru, showed significant differences in group densities between forest boundaries and forest interior, suggesting the area harbours roughly 1,150 titi monkeys.
Abstract: We calculated the population density of the critically endangered Callicebus oenanthe in the Ojos de Agua Conservation Concession, a dry forest area in the department of San Martin, Peru. Results showed significant differences (p 2, IQR = 21.1-11.0) and forest interior (4.0 groups/km2, IQR = 5.0-0.0), suggesting the 2,550-ha area harbours roughly 1,150 titi monkeys. This makes Ojos de Agua an important cornerstone in the conservation of the species, because it is one of the largest protected areas where the species occurs.
TL;DR: Data suggest that the L. catta populations within south-central Madagascar have not yet lost significant genetic variation, however, due to ongoing anthropogenic threats faced by ring-tailed lemurs, continued conservation and research initiatives are imperative for long-term viability of the species.
Abstract: Madagascar's lemurs, now deemed the most endangered group of mammals, represent the highest primate conservation priority in the world. Due to anthropogenic disturbances, an estimated 10% of Malagasy forest cover remains. The endangered Lemur catta is endemic to the southern regions of Madagascar and now occupies primarily fragmented forest habitats. We examined the influence of habitat fragmentation and isolation on the genetic diversity of L. catta across 3 different forest fragments in south-central Madagascar. Our analysis revealed moderate levels of genetic diversity. Genetic differentiation among the sites ranged from 0.05 to 0.11. These data suggest that the L. catta populations within south-central Madagascar have not yet lost significant genetic variation. However, due to ongoing anthropogenic threats faced by ring-tailed lemurs, continued conservation and research initiatives are imperative for long-term viability of the species.
TL;DR: The species is behaviourally able to adjust to captivity, but the slight differences along the continuum from wild to semi-free to captive are suggestive of mild stress or social tension probably due to unstimulating environmental conditions, high visitor pressure and deviations from typical sex-age group composition.
Abstract: The behavioural repertoires and time budgets of 2 captive groups and 1 semi-free-ranging group of Cebus olivaceus were determined with the aim to assess the impact of the zoo environment on behaviour. The repertoires were qualitatively similar between groups and to those reported for wild troops, but the captive groups showed self-directed and stereotyped behaviours not reported in the wild. The differences in repertoires between groups were easily associated with the opportunity to interact directly with the visitors, with particularities of the enclosure and with the severity of confinement. Overall, females spent more time foraging than males in the 2 captive groups, and adults rested and watched more than subadults in all the groups. Time budgets were dominated by foraging, resting, movement and affiliative interactions, but their relative importance varied between groups, with foraging being especially prominent in the most confined group. The time budgets also varied qualitatively from those reported for wild troops. We conclude the species is behaviourally able to adjust to captivity, but the slight differences along the continuum from wild to semi-free to captive are suggestive of mild stress or social tension probably due to unstimulating environmental conditions, high visitor pressure and deviations from typical sex-age group composition.
TL;DR: It is suggested that choosing foods high in protein, relatively low in fiber and with high water content are behavioral adaptations allowing female L. catta to reproduce and survive in this habitat.
Abstract: The spiny forest ecoregion of southern and southwestern Madagascar is characterized by low annual rainfall, high temperatures, short-stature xeric vegetation and lack of canopy. Lemur catta is often the only diurnal primate persisting in this habitat. For reproductive females living in spiny forests, gestation and early-to-mid lactation periods occur during the dry season when food resources are limited. We conducted a between-site comparison of variables important to the feeding ecology of reproductive female L. catta inhabiting spiny forest at 3 sites: Berenty spiny forest (BSF), Cap Sainte-Marie (CSM) and Tsimanampesotse National Park (TNP). We hypothesize that the ability for pregnant and lactating females to adequately obtain plant foods high in protein, low in fiber and with a high water content is crucial to their survival and successful reproduction in spiny habitat. We found favorable or relatively equal protein-to-fiber ratios in plant foods most frequently consumed by reproductive females, and preferred foods contained high water content. Some overlap in preferred plant species at the 3 sites suggests important plant foods for reproductive females inhabiting spiny forests. We suggest that choosing foods high in protein, relatively low in fiber and with high water content are behavioral adaptations allowing female L. catta to reproduce and survive in this habitat.
TL;DR: Assessment of wild, free-ranging ring-tailed lemurs at the Bezà Mahafaly Special Reserve found biomedical markers suggestive of decreased hydration can provide empirical data to inform new conservation policies facilitating the long-term survival of this lemur community.
Abstract: The health of 36 wild, free-ranging ring-tailed lemurs (Lemur catta) at the Beza Mahafaly Special Reserve was assessed across 2 habitats of varied human impact: a reserve riverine gallery forest, and a degraded mixed dry deciduous and Alluaudia-dominated spiny forest. While there were no statistically significant differences in leukocyte count or differential between habitats, female lemurs in the reserve gallery forest had significantly higher percentages of monocytes and eosinophils than male lemurs in the gallery forest. Lemurs from the degraded spiny habitat had significantly higher mean packed cell volume, hematocrit, hemoglobin, total protein, blood urea nitrogen, chloride, ionized calcium and urine specific gravity than lemurs from the reserve gallery forest. These findings may reflect lower hydration levels in lemurs living in degraded habitat, providing evidence that environmental degradation has identifiable impacts on the physiology and health of wild, free-ranging ring-tailed lemurs living in nearby habitats. Given the greater evidence of human impact in the mixed dry deciduous/spiny forest habitat, a pattern seen throughout southern Madagascar, biomedical markers suggestive of decreased hydration can provide empirical data to inform new conservation policies facilitating the long-term survival of this lemur community.
TL;DR: Comparisons of nested bayesian Markov chain Monte Carlo models of independent and dependent evolution of juvenile infant interest and adult infant care indicate strong support for coevolution of juvenile infants interest andAdult infant care, andExpanding comparative analysis to include available data from lemurs strengthens this support, suggesting that the function of juveniles infant interest does not differ between strepsirrhines and haplorhines.
Abstract: Female-biased juvenile interest in infants is common in primates. Proposed hypotheses to explain juvenile infant interest are that it helps immature individuals learn to parent, is a by-product of selection on adult infant care behavior, is kin-selected cooperative rearing, or is a form of harassment. If juvenile infant interest is associated with adult infant care, either functionally or as a by-product, sex-biased patterns of juvenile infant interest and adult infant care should show correlated evolution; if juvenile infant interest functions as cooperative rearing or harassment, they should not. Comparisons of nested bayesian Markov chain Monte Carlo models of independent and dependent evolution of juvenile infant interest and adult infant care indicate strong support for coevolution of juvenile infant interest and adult infant care. Expanding comparative analysis to include available data from lemurs strengthens this support, suggesting that the function of juvenile infant interest does not differ between strepsirrhines and haplorhines. As such, strepsirrhine taxa currently maintained in captivity will be particularly useful in future work aiming to test between the learning to parent and by-product hypotheses for juvenile infant interest.
TL;DR: The results showed that the lower molar shape of cercopithecoid primates reflects taxonomic affinities, mostly at a subfamily level and close to a tribe level, and the cusp positions and crown contour were important elements of the pattern related to interspecific variation.
Abstract: Morphometric variation of biological structures has been widely used to determine taxonomic affinities among taxa, and teeth are especially informative for both deep phylogenetic relationships and specific ecological signals. We report 2-dimensional geometric morphometrics (GM) analyses of occlusal crown surfaces of lower molars (M1, n = 141; M2, n = 158) of cercopithecoid primate species. A 12-landmark configuration, including cusp tips and 8 points of the molar crown contour, were used to evaluate patterns of variation in lower molar shape among cercopithecoid primates and to predict the taxonomic attribution of 2 archaeological macaques from Roman time periods. The results showed that the lower molar shape of cercopithecoid primates reflects taxonomic affinities, mostly at a subfamily level and close to a tribe level. Thus, the cusp positions and crown contour were important elements of the pattern related to interspecific variation. Additionally, the archaeological specimens, attributed to Macaca sylvanus based on osteological information, were classified using the GM molar shape variability of the cercopithecoid primates studied. The results suggest that their molar shape resembled both M. sylvanus and M. nemestrina, and species attribution varied depending on the comparative sample used.
TL;DR: The ring-tailed lemur diet is a mixture of plants that are eaten in abundance regardless of frequency and those that are locally available, and in terms of their reliance on Tamarindus, P2 animals appear intermediate between those in gallery forests and nontamarind sites.
Abstract: Ring-tailed lemurs have been studied intensively in the Parcel 1 gallery forest of Beza Mahafaly Special Reserve. Here, we report on lemur groups in a mixture of deciduous dry forest and spiny forest just 5 km to the west. Compared to Parcel 1, Parcel 2 (P2) has a lower density of Tamarindus indica, a major dietary plant species for gallery forest lemurs. Recent studies in drier habitats have called into question the association of lemur density and tamarind presence. In order to address this question, we measured forest structure and composition of plant plots between parcels and conducted lemur feeding observations. The trees and shrubs within the parcels did not differ in height or diameter at breast height, but the frequencies of plant species that were common between parcels were significantly different. Numbers of feeding observations on foods common to both parcels did not differ, but their relative rankings within parcels did. Frequencies of food plants corresponded to earlier reports of lemur population densities. However, we found that the ring-tailed lemur diet is a mixture of plants that are eaten in abundance regardless of frequency and those that are locally available. In terms of their reliance on Tamarindus, P2 animals appear intermediate between those in gallery forests and nontamarind sites.
TL;DR: This work replaces a fruit penetrometer's standard plunger with a Cacajao calvus canine prosthesis and believes this new approach using dental prostheses has potential in the analysis of primate foraging mechanisms, especially for pitheciines for which canines are of paramount importance in accessing food.
Abstract: Tooth morphology is an important determinant of primate diet, setting potential limits on processable item size and material properties. Plunger-based commercial fruit firmness testers (penetrometers) have been used to estimate primate diet item hardness and, by proxy, bite force required for penetration. However, geometric forms and surface areas of penetrometer plungers and primate teeth differ considerably. Accurate bite force estimation is especially important with pitheciine primates as these penetrate fruit pericarps with their canines. To achieve more realistic bite force measures, we replaced a fruit penetrometer's standard plunger with a Cacajao calvus canine prosthesis. We compared indentation and penetration values for Hevea spruceana (Euphorbiaceae; hard-pericarp) and Mauritia flexuosa (Arecaceae; soft-pericarp) fruits (both natural Cacajao foods), and standard penetrometer head and canine prosthesis values for penetrating H. spruceana sulci. Compared to the canine prosthesis, a standard head overestimated the force needed to indent and penetrate H. spruceana fruit by more than twofold and, due to greater width, could not effectively penetrate a sulcus: sulcal penetrability data were easily retrieved with the canine prosthesis. We believe this new approach using dental prostheses has potential in the analysis of primate foraging mechanisms, especially for pitheciines for which canines are of paramount importance in accessing food.
TL;DR: The focus of this special volume is to ‘re-imagine' the ‘flagship species of Madagascar', bringing together three generations of lemur scholars.
Abstract: For over 50 years, ring-tailed lemurs have been studied continuously in the wild. As one of the most long-studied primate species, the length and breadth of their study is comparable to research on Japanese macaques, baboons and chimpanzees. They are also one of the most broadly observed of all primates, with comprehensive research conducted on their behaviour, biology, ecology, genetics, palaeobiology and life history. However, over the last decade, a new generation of lemur scholars, working in conjunction with researchers who have spent decades studying this species, have greatly enhanced our knowledge of ring-tailed lemurs. In addition, research on this species has expanded beyond traditional gallery forest habitats to now include high altitude, spiny thicket, rocky outcrop and anthropogenically disturbed coastal forest populations. The focus of this special volume is to 're-imagine' the 'flagship species of Madagascar', bringing together three generations of lemur scholars.
TL;DR: This study established that Nilgiri langurs were more folivorous than Hanuman langurs, and compared food items and activity budgets of two closely related species of colobines inhabiting South India to determine whether folivory had an impact on social time in these species.
Abstract: Folivory, being a dietary constraint, can affect the social time of colobines. In the present study, we compared food items and activity budgets of two closely related species of colobines inhabiting South India, i.e. the Hanuman langur (Semnopithecus hypoleucos) and Nilgiri langur (Semnopithecus johnii), to determine whether folivory had an impact on social time in these species. Our study established that Nilgiri langurs were more folivorous than Hanuman langurs. Nilgiri langurs spent much less time on social activities, but more time on resting, although the social organization of S. hypoleucos was similar to that of the Nilgiri langur. The enforced resting time for fermentation of leafy food items may have reduced the time available for social interactions, which in turn affected the social time in Nilgiri langurs. By comparing the data from previous studies on other Hanuman langur species, we found that S. hypoleucos spent a similar amount of time on social activities as Semnopithecus entellus. Hence, the social behaviour of S. entellus and S. hypoleucos is phylogenetically highly conservative.
TL;DR: The study revealed stable linear dominance hierarchies in females within each group and highlighted the flexibility and adaptability of the HPA system in ring-tailed lemurs.
Abstract: In ring-tailed lemurs, Lemur catta, the factors modulating hypothalamic-pituitary-adrenal (HPA) activity differ between wild and semi-free-ranging populations. Here we assess factors modulating HPA activity in ring-tailed lemurs housed in a third environment: the zoo. First we validate an enzyme immunoassay to quantify levels of glucocorticoid (GC) metabolites in the faeces of L. catta. We determine the nature of the female-female dominance hierarchies within each group by computing David's scores and examining these in relation to faecal GC (fGC). Relationships between female age and fGC are assessed to evaluate potential age-related confounds. The associations between fGC, numbers of males in a group and reproductive status are explored. Finally, we investigate the value of 7 behaviours in predicting levels of fGC. The study revealed stable linear dominance hierarchies in females within each group. The number of males in a social group together with reproductive status, but not age, influenced fGC. The 7 behavioural variables accounted for 68% of the variance in fGC. The amounts of time an animal spent locomoting and in the inside enclosure were both negative predictors of fGC. The study highlights the flexibility and adaptability of the HPA system in ring-tailed lemurs.