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Primates exhibit diverse social systems that are intricately linked to their biology, behavior, and evolution, all of which influence the acquisition and maintenance of their gut microbiomes (GMs). However, most studies of wild primate populations focus on taxa with relatively large group sizes, and few consider pair‐living species. To address this gap, we investigate how a primate's social system interacts with key environmental, social, and genetic variables to shape the GM in pair‐living, red‐bellied lemurs (Eulemur rubriventer). Previous research on this species suggests that social interactions within groups influence interindividual microbiome similarity; however, the impacts of other nonsocial variables and their relative contributions to gut microbial variation remain unclear. We sequenced the 16S ribosomal RNA hypervariable V4–V5 region to characterize the GM from 26 genotyped individuals across 11 social groups residing in Ranomafana National Park, Madagascar. We estimated the degree to which sex, social group identity, genetic relatedness, dietary diversity, and home range proximity were associated with variation in the gut microbial communities residing in red‐bellied lemurs. All variables except sex played a significant role in predicting GM composition. Our model had high levels of variance inflation, inhibiting our ability to determine which variables were most predictive of gut microbial composition. This inflation is likely due to red‐bellied lemurs' pair‐living, pair‐bonded social system that leads to covariation among environmental, social, and genetic variables. Our findings highlight some of the factors that predict GM composition in a tightly bonded, pair‐living species and identify variables that require further study. We propose that future primate microbiome studies should simultaneously consider environmental, social, and genetic factors to improve our understanding of the relationships among sociality, the microbiome, and primate ecology and evolution. Research Highlights: We highlight diverse social, environmental, and genetic factors that shape the red‐bellied lemur gut microbiome (GM) and encourage additional comparative studies with other pair‐living primate species to further investigate GM variation within the context of a pair‐living social organization.Multicollinearity among predictor variables—likely due to red‐bellied lemurs' social system—hindered our ability to estimate the relative contributions of each variable in predicting GM variation.We caution future microbiome studies to assess their variables for multicollinearity before analyses. [ABSTRACT FROM AUTHOR]

The Papillomaviridae are a family of vertebrate-infecting viruses of oncogenic potential generally thought to be host species- and tissue-specific. Despite their phylogenetic relatedness to humans, there is a scarcity of data on papillomaviruses (PVs) in speciose non-human primate lineages, particularly the lemuriform primates. Varecia variegata (black-and-white ruffed lemurs) and Varecia rubra (red ruffed lemurs), two closely related species comprising the Varecia genus, are critically endangered with large global captive populations. Varecia variegata papillomavirus (VavPV) types −1 and −2, the first PVs in lemurs with a fully identified genome, were previously characterized from captive V. variegata saliva. To build upon this discovery, saliva samples were collected from captive V. rubra with the following aims: (1) to identify PVs shared between V. variegata and V. rubra and (2) to characterize novel PVs in V. rubra to better understand PV diversity in the lemuriform primates. Three complete PV genomes were determined from V. rubra samples. Two of these PV genomes share 98% L1 nucleotide identity with VavPV2, denoting interspecies infection of V. rubra by VavPV2. This work represents the first reported case of interspecies PV infection amongst the strepsirrhine primates. The third PV genome shares <68% L1 nucleotide identity with that of all PVs. Thus, it represents a new PV species and has been named Varecia rubra papillomavirus 1 (VarPV1). VavPV1, VavPV2, and VarPV1 form a new clade within the Papillomaviridae family, likely representing a novel genus. Future work diversifying sample collection (i.e., lemur host species from multiple genera, sample type, geographic location, and wild populations) is likely to uncover a world of diverse lemur PVs. [ABSTRACT FROM AUTHOR]

Age and sex have a profound effect on cytosine methylation levels in humans and many other species. Here we analyzed DNA methylation profiles of 2400 tissues derived from 37 primate species including 11 haplorhine species (baboons, marmosets, vervets, rhesus macaque, chimpanzees, gorillas, orangutan, humans) and 26 strepsirrhine species (suborders Lemuriformes and Lorisiformes). From these we present here, pan-primate epigenetic clocks which are highly accurate for all primates including humans (age correlation R = 0.98). We also carried out in-depth analysis of baboon DNA methylation profiles and generated five epigenetic clocks for baboons (Olive-yellow baboon hybrid), one of which, the pan-tissue epigenetic clock, was trained on seven tissue types (fetal cerebral cortex, adult cerebral cortex, cerebellum, adipose, heart, liver, and skeletal muscle) with ages ranging from late fetal life to 22.8 years of age. Using the primate data, we characterize the effect of age and sex on individual cytosines in highly conserved regions. We identify 11 sex-related CpGs on autosomes near genes (POU3F2, CDYL, MYCL, FBXL4, ZC3H10, ZXDC, RRAS, FAM217A, RBM39, GRIA2, UHRF2). Low overlap can be observed between age- and sex-related CpGs. Overall, this study advances our understanding of conserved age- and sex-related epigenetic changes in primates, and provides biomarkers of aging for all primates. [ABSTRACT FROM AUTHOR]

In 1758, Carl von Linné (Linnaeus) published the tenth edition of Systema Naturae, in which he formally described the most unique group of primates: lemurs. The story of the early human-mediated dispersal of lemurs from Madagascar, prior to their formalized descriptions, is a complex one. It touches on the birth of the standardization of modern zoology, empire building, and the growth of international trade and commerce, with many Fellows of the Royal Society contributing to the earliest observations of these animals in captive settings. Through the use of historical documents and artwork, we present this history in four parts: 'Part I: The lemurs that became 'lemurs' (1746–1756)', discusses the specific lemurs that Linnaeus used to describe the genera in the tenth and twelfth editions of Systema Naturae; 'Part II: Establishing the trade routes (1500–1662)', examines seventeenth century captive lemurs and the role of the trade routes of the East India Companies in the transportation of lemurs from Madagascar; 'Part III: Tracing the Bugée (1693–1732)', reviews the lemurs identified by late seventeenth and early eighteenth century pre-Linnaean naturalists; and 'Part IV: The chained lemur (1732–1761)', concludes with eighteenth century lemurs in menageries and as luxury goods. [ABSTRACT FROM AUTHOR]

Animal groups regularly lose group members as a result of death and dispersal, but the consequences of such a loss on the social relationships among the remaining group members remain generally understudied. Moreover, some of the few studies on this topic reported destabilizing effects of group member loss in some species, whereas in other species individuals apparently compensated for lost partners by strengthening remaining relationships. However, it remains unknown what may drive these contrasting effects in different species. Here, we investigated the impact of the loss of an individual on subsequent social patterns in a basal group-living primate, the redfronted lemur. Using focal animal observation data surrounding 16 disappearance events (five dispersals and 11 predation events) in four groups of wild redfronted lemurs, we tested for changes in the coefficient of variation of relationship strength in affiliative interaction networks, as well as for changes in affiliative and agonistic interaction rates. We found no evidence for significant changes in any of the three measures, indicating that the disappearance of a group member is not reflected by a change in social interactions among redfronted lemurs. Yet, the fact that rates of social interactions did not change significantly indicates that they compensated for the loss of a group member by redistributing their social behaviour towards other individuals. Our study therefore indicates that redfronted lemurs' social interactions are resilient to group member loss. Alternatively, the number of unpredictable disappearance events in our retrospective study may have been too small to detect any effects, underscoring the need for additional comparative research on this topic to determine whether methodological constraints or particular coping mechanisms underly this apparent contrast with anthropoid primates. • First study on influence of group member loss in a strepsirrhine primate. • Disappearance of a group member had no effect on social network measures. • Disappearance of a group member did not affect affiliative and agonistic behaviour. [ABSTRACT FROM AUTHOR]

Tropical forests support a diversity of plants. Many of them are threatened, emphasising that their shared use by people and wildlife may benefit their conservation. Litt forests of southeast Madagascar, home to seven threatened lemur species, provide the Antanosy people with natural resources. In the early 2000s, protected areas were established in two regions that historically incurred different levels of anthropogenic pressures: Sainte Luce and Mandena. We explored the local use of plants as medicine, construction materials and firewood, and examined the overlap of plants used by people and the red-collared brown lemur (Eulemur collaris), the largest lemur in this ecosystem and an important seed disperser. Between July and October 2018, 60 adults (30 women, 30 men) participated in semi-structured interviews. Our findings show 122 plants are locally used as medicines, 60 as construction materials, and 71 as firewood. Of all utilitarian plants, 52 were confirmed in this lemur's diet. Sainte Luce participants reported they used a higher diversity of species in all three categories. Western medicines were available and preferred to medicinal plants, but the choice also often depended on the health condition being addressed. Firewood was preferred to charcoal for cooking. Resource restrictions of the protected areas has negatively affected the local people. Local ethnobotanical knowledge reflects the importance of plants, while differences in plant use of the two communities reflect differences in biodiversity and socio-economic circumstances. Emphasising this interdependence, especially in forest restoration, could be a path towards conservation of plants, lemurs, and people, as well as traditional livelihoods. [ABSTRACT FROM AUTHOR]

The gut microbiome can mediate host metabolism, including facilitating energy-saving strategies like hibernation. The dwarf lemurs of Madagascar (Cheirogaleus spp.) are the only obligate hibernators among primates. They also hibernate in the subtropics, and unlike temperate hibernators, fatten by converting fruit sugars to lipid deposits, torpor at relatively warm temperatures, and forage for a generalized diet after emergence. Despite these ecological differences, we might expect hibernation to shape the gut microbiome in similar ways across mammals. We, therefore, compare gut microbiome profiles, determined by amplicon sequencing of rectal swabs, in wild furry-eared dwarf lemurs (C. crossleyi) during fattening, hibernation, and after emergence. The dwarf lemurs exhibited reduced gut microbial diversity during fattening, intermediate diversity and increased community homogenization during hibernation, and greatest diversity after emergence. The Mycoplasma genus was enriched during fattening, whereas the Aerococcaceae and Actinomycetaceae families, and not Akkermansia , bloomed during hibernation. As expected, the dwarf lemurs showed seasonal reconfigurations of the gut microbiome; however, the patterns of microbial diversity diverged from temperate hibernators, and better resembled the shifts associated with dietary fruits and sugars in primates and model organisms. Our results thus highlight the potential for dwarf lemurs to probe microbiome-mediated metabolism in primates under contrasting conditions. [ABSTRACT FROM AUTHOR]

Developing new cost-effective methods for monitoring the distribution and abundance of species is essential for conservation biology. Passive acoustic monitoring (PAM) has long been used in marine mammals and has recently been postulated to be a promising method to improve monitoring of terrestrial wildlife as well. Because Madagascar's lemurs are among the globally most threatened taxa, this study was designed to assess the applicability of an affordable and open-source PAM device to estimate the density of pale fork-marked lemurs (Phaner pallescens). Using 12 playback experiments and one fixed transect of four automated acoustic recorders during one night of the dry season in Kirindy Forest, we experimentally estimated the detection space for Phaner and other lemur vocalizations. Furthermore, we manually annotated more than 10,000 vocalizations of Phaner from a single location and used bout rates from previous studies to estimate density within the detection space. To truncate detections beyond 150 m, we applied a sound pressure level (SPL) threshold filtering out vocalizations below SPL 50 (dB re 20 μPa). During the dry season, vocalizations of Phaner can be detected with confidence beyond 150 m by a human listener. Within our fixed truncated detection area corresponding to an area of 0.07 km2 (detection radius of 150 m), we estimated 10.5 bouts per hour corresponding to a density of Phaner of 38.6 individuals/km2. Our density estimates are in line with previous estimates based on individually marked animals conducted in the same area. Our findings suggest that PAM also could be combined with distance sampling methods to estimate densities. We conclude that PAM is a promising method to improve the monitoring and conservation of Phaner and many other vocally active primates. [ABSTRACT FROM AUTHOR]

Aim: Global animal populations are in decline due to destruction and degradation of their natural habitat. Understanding the factors that determine the distribution and density of threatened animal populations is therefore now a crucial component of their study and conservation. The Cheirogaleidae are a diverse family of small‐bodied, nocturnal lemurs that are widespread throughout the forests of Madagascar. However, many cheirogaleid lemurs are now highly threatened with extinction and the environmental factors that determine their distribution and population density are still little known. Here, I investigated the environmental drivers of Cheirogaleidae population density at genus level. Location: Various forest sites across Madagascar. Methods: I investigated how six environmental variables affect Cheirogaleidae population density at the genus level via random‐effect meta‐analyses. I then used a generalized linear mixed‐effects model to identify the primary predictors of Cheirogaleidae population density. Finally, I investigated how the population density of this family of lemurs varies between protected and unprotected areas of Madagascar via a GLM analysis. Results: My results indicate that the relationships between the tested environmental factors and population density are genus‐specific among the Cheirogaleidae. Rather remarkably, the density of Microcebus appears to have a profoundly positive relationship with anthropogenic disturbance and a negative relationship with forest cover, a finding that is also reflected by larger population densities within unprotected areas in comparison with localities within Madagascar's protected area network. Main Conclusions: The results of this study are highly encouraging for the conservation of the Cheirogaleidae and highlight the remarkable resilience of these lemurs to habitat degradation and anthropogenic activity. However, this study also outlines the dearth of knowledge that we have for many species, and why these data are urgently needed to understand the biogeography and ecology of threatened animal populations and implement successful conservation. [ABSTRACT FROM AUTHOR]

Bitter taste facilitates the detection of potentially harmful substances and is perceived via bitter taste receptors (TAS2Rs) expressed on the tongue and oral cavity in vertebrates. In primates, TAS2R16 specifically recognizes β-glucosides, which are important in cyanogenic plants' use of cyanide as a feeding deterrent. In this study, we performed cell-based functional assays for investigating the sensitivity of TAS2R16 to β-glucosides in three species of bamboo lemurs (Prolemur simus, Hapalemur aureus and H. griseus), which primarily consume high-cyanide bamboo. TAS2R16 receptors from bamboo lemurs had lower sensitivity to β-glucosides, including cyanogenic glucosides, than that of the closely related ring-tailed lemur (Lemur catta). Ancestral reconstructions of TAS2R16 for the bamboo-lemur last common ancestor (LCA) and that of the Hapalemur LCA showed an intermediate sensitivity to β-glucosides between that of the ring-tailed lemurs and bamboo lemurs. Mutagenetic analyses revealed that P. simus and H. griseus had separate species-specific substitutions that led to reduced sensitivity. These results indicate that low sensitivity to β-glucosides at the cellular level—a potentially adaptive trait for feeding on cyanogenic bamboo—evolved independently after the Prolemur–Hapalemur split in each species. [ABSTRACT FROM AUTHOR]

The two captive red-ruffed lemurs (Varecia rubra) at the Central Florida Zoo experienced a more temperate climate and utilized a differing habitat than they would in their native range, Madagascar. Proper management of the species in captivity is crucial for its long-term survival as they are critically endangered. Over a four month period, heat index temperature, lemur behavior, and habitat utilization data were collected via an instantaneous scan sample. Variables were analyzed to characterize how variations in heat index alter habitat utilization and behavior of the captive lemurs. As the heat index increased, habitat use became more restricted with a bias towards shaded areas. Similarly, behavior diversity declined as heat index rose, with a heavy bias towards loafing. However, at every heat index range, both utilization of the enclosure's shaded portion and loafing behaviors were disproportionately more common than any other location or behavior. Data from this study suggested that heat index temperature influenced both the behavior diversity and habitat utilization in the two captive Varecia rubra. [ABSTRACT FROM AUTHOR]

Habituation is a preliminary process, allowing observers to become more familiar with animals and record their behavior. Few studies have described the habituation process for non-human primate species and there is a dearth of information on the habituation process among lemurs. This study describes the habituation of the Critically Endangered greater bamboo lemur (Prolemur simus). We used continuous focal animal sampling (384 hours) to collect behavioral data on seven individuals from two groups in the Vatovavy forest, southeastern Madagascar. We categorized our behavior data into two response types: habituated behaviors and non-habituated behaviors. Study animals were considered habituated when they showed an increased tolerance to human observers permitting focal animal data collection with minimal non-habituated responses. There were no significant differences among individuals for both habituated and non-habituated behaviors, therefore, all data were pooled together. Distance from observer and height of animals in the forest significantly decreased during the habituation process. By the end of the study, the frequency of habituated behaviors significantly increased. In conjunction with previously reported findings for this species, this study concludes that greater bamboo lemurs can be habituated in approximately 13-16 weeks. [ABSTRACT FROM AUTHOR]

Inference by exclusion, or the ability to select a correct course of action by systematically excluding other potential alternatives, is a form of logical inference that allows individuals to solve problems without complete information. Current comparative research shows that several bird, mammal and primate species can find hidden food through inference by exclusion. Yet there is also wide variation in how successful different species are as well as the kinds of sensory information they can use to do so. An important question is therefore why some species are better at engaging in logical inference than others. Here, we investigate the evolution of logical reasoning abilities by comparing strepsirrhine primate species that vary in dietary ecology: frugivorous ruffed lemurs (Varecia spp.) and folivorous Coquerel's sifakas, Propithecus coquereli. Across two studies, we examined their abilities to locate food using direct information versus inference from exclusion and using both visual and auditory information. In study 1, we assessed whether these lemurs could make inferences when full visual and auditory information about the two potential locations of food were provided. In study 2, we then compared their ability to make direct inferences versus inferences by exclusion in both the visual and auditory domains. We found that these lemur species can use visual information to find food, but that only ruffed lemurs were also able to use auditory cues, mirroring differences in the complexity of their wild ecology. We further found that, unlike many anthropoid species tested to date, these strepsirrhine species failed to make inferences by exclusion. These results highlight the importance of natural history in understanding the evolution of logical inference and help reconstruct the deeper phylogeny of primate cognition. • Species vary in capacities for logical inference, such as inference by exclusion. • We tested how two lemur species with different ecologies solve such problems. • Lemurs were more successful using visual than auditory information to find food. • Lemurs made inferences from direct information, but not via exclusion. • Only frugivorous ruffed lemurs exploited both sensory modalities. [ABSTRACT FROM AUTHOR]

Environmental enrichment has become a standard tool for improving the welfare of animals in zoos. Two critical steps in the manipulation of environmental enrichment are (1) selection of objects/procedures and (2) evaluation of their effects. In this study, we examined the selection and evaluation of feeding enrichment for four species of lemur. Experiment 1 used a paired-choice preference assessment to divide eight food items into high- and low-preferred categories. Experiment 2 separately assessed the effects of high- versus low-preferred items (placed in bamboo dispensers) on the behavior of two of the species in the preference assessment. Both high- and low-preferred items increased general activity and overall enclosure use, with high-preferred items having a greater effect than low-preferred items on most measures. The results suggest that preference assessments can serve as useful tools in selecting potential enrichment and that enrichment testing is important in evaluating the significance of these preferences. [ABSTRACT FROM AUTHOR]

Bitter taste enables the detection of potentially harmful substances and is mediated by bitter taste receptors, TAS2Rs, in vertebrates. Few antagonists and inverse agonists of TAS2Rs have been identified, especially natural compounds. TAS2R16s in humans, apes and Old World monkeys (Catarrhini, Anthropoidea) recognize β-glucoside analogues as specific agonists. Here, we investigated responses of TAS2R16 to β-glucosides in non-anthropoid primates, namely lemurs (Lemuriformes, Strepsirrhini). Salicin acted as an agonist on lemur TAS2R16. Arbutin acted as an agonist in the ring-tailed lemur (Lemur catta) but as an inverse agonist in black lemur (Eulemur macaco) and black-and-white ruffed lemur (Varecia variegata). We identified a strepsirrhine-specific amino acid substitution responsible for the inverse agonism of arbutin. In a food preference test, salicin bitterness was inhibited by arbutin in the black lemur. Structural modelling revealed this locus was important for a rearrangement of the intracellular end of transmembrane helix 7 (TM7). Accordingly, arbutin is the first known natural inverse agonist of TAS2Rs, contributing to our understanding of receptor–ligand interactions and the molecular basis of the unique feeding habit diversification in lemurs. Furthermore, the identification of a causal point mutation suggests that TAS2R can acquire functional changes according to feeding habits and environmental conditions. [ABSTRACT FROM AUTHOR]

Madagascar is the habitat of 5% of the world's flora and fauna; more than 80% of which are endemic, including 113 lemurs species. Despite the endemism of lemurs, few Malagasy people living in cities (especially younger generations) have heard about lemurs or are even aware of their threat to the survival of lemurs. To address this issue, we conducted an educational project in high schools in order to increase awareness of the importance of lemurs. During two months in 2015, we provided 6 lectures about lemurs to students in two high schools in the capital of Madagascar. Each lecture per class lasted approximately 2 hours, including questionnaires. A total of 236 students (aged 14 to 15 years) took part in the survey. Before the lectures, the majority of students (92%) knew lemurs as mammals and only 29% of them were able to draw an accurate picture of a lemur. After the lectures, 80% of the students could concisely define what lemurs were. Major threats to lemurs were understood by approximately 92% of students and 51% of students knew that lemurs are forest dwellers. All students reported that they enjoyed the lesson and were motivated to contribute to the protection of Madagascar's biodiversity such as participation in reforestation and attending lemur festivals. These findings highlight the success of such an approach in increasing the awareness of young people with respect to the importance of lemurs. We advocate the use of lectures and involvement of students in discussions about lemurs to help protect lemur populations in the future. [ABSTRACT FROM AUTHOR]

We diagnosed tuberculosis in an illegally wild-captured pet ring-tailed lemur manifesting lethargy, anorexia, and cervical lymphadenopathy. Whole-genome sequencing confirmed the Mycobacterium tuberculosis isolate belonged to lineage 3 and harbored streptomycin resistance. We recommend reverse zoonosis prevention and determination of whether lemurs are able to maintain M. tuberculosis infection. [ABSTRACT FROM AUTHOR]

Abstract: Vertebrate gut microbiota form a key component of immunity and a dynamic link between an individual and the ecosystem. Microbiota might play a role in social systems as well, because microbes are transmitted during social contact and can affect host behaviour. Combining methods from behavioural and molecular research, we describe the relationship between social dynamics and gut microbiota of a group‐living cooperative species of primate, the red‐bellied lemur (Eulemur rubriventer). Specifically, we ask whether patterns of social contact (group membership, group size, position in social network, individual sociality) are associated with patterns of gut microbial composition (diversity and similarity) between individuals and across time. Red‐bellied lemurs were found to have gut microbiota with slight temporal fluctuations and strong social group‐specific composition. Contrary to expectations, individual sociality was negatively associated with gut microbial diversity. However, position within the social network predicted gut microbial composition. These results emphasize the role of the social environment in determining the microbiota of adult animals. Since social transmission of gut microbiota has the potential to enhance immunity, microbiota might have played an escalating role in the evolution of sociality. [ABSTRACT FROM AUTHOR]

Madagascar is a threatened global biodiversity hotspot and conservation priority, yet we lack broad‐scale surveys to assess biodiversity across space and time. To fill this gap, we collated camera trap surveys, capturing species occurrences within Madagascar into a single standardized database. This data set includes nine distinct protected areas of Madagascar and encompasses 13 subprojects, 38 camera arrays, and 1156 sampling units (independent camera site per survey) within two important biodiversity eco‐regions: western dry deciduous forest and eastern humid rainforest. Camera surveys were conducted from June 2007 to January 2021. The final data set includes 17 unique families of mammals (Bovidae, Canidae, Cheirogaleidae, Daubentoniidae, Equidae, Eupleridae, Felidae, Hominidae, Indriidae, Lemuridae, Lepilemuridae, Muridae, Nesomyidae, Pteropodidae, Soricidae, Suidae, Tenrecidae) comprising 45 species and 27 unique families of birds (Accipitridae, Acrocephalidae, Alcedinidae, Bernieridae, Brachypteraciidae, Caprimulgidae, Cisticolidae, Columbidae, Coraciidae, Corvidae, Cuculidae, Dicruridae, Mesitornithidae, Monarchidae, Motacillidae, Muscicapidae, Numididae, Phasianidae, Rallidae, Sarothruridae, Strigidae, Sturnidae, Sulidae, Threskiornithidae, Upupidae, Vangidae, Zosteropidae) comprising 58 species. Images were processed and verified by individual project data set creators and camera operation and species tables were then collated. The final product represents the first broad‐scale freely available standardized formal faunal database for Madagascar. Data are available through this publication and at DOI: 10.5281/zenodo.5801806. These data will be useful for examining species‐level and community‐level trends in occurrence across space or time within Madagascar and globally, evaluating native and invasive species dynamics, and will aid in determining species conservation status and planning for at‐risk species. There are no copyright restrictions; please cite this paper when using the data for publication. [ABSTRACT FROM AUTHOR]

Tapeworms of the genus Echinococcus reside in the small intestine of a number of carnivorous species, predominantly canids. In enzootic areas, hydatidosis caused by taeniid metacestodes can present a significant problem in accidental intermediate hosts, including humans. Whereas the United Kingdom is currently considered free of Echinococcus multilocularis , Echinococcus granulosus sensu stricto (s.s.) and Echinococcus equinus are endemic in the UK and have been reported in a variety of captive mammals. The presentation of echinoccocosis in non-human primates widely parallels disease in humans, and public health concerns are related to the four genera, E. granulosus , E. multilocularis , Echinococcus vogeli and Echinococcus oligarthrus . In contrast, sporadic outbreaks and individual hydatid disease cases in non-human primates have been associated with several Echinococcus and Taenia species. Here we describe three fatal cases of cystic echinococcosis in two captive ring-tailed lemurs ( Lemur catta ) and one captive red-ruffed lemur ( Varecia variegata rubra ) and provide molecular tapeworm characterisation. To the best of the authors’ knowledge, this includes the first report of Echinococcus ortleppi in a UK born ring-tailed lemur and provides the first in depth case reports of echinococcosis due to E. equinus in UK born ring-tailed and red ruffed lemurs with detailed clinical and pathological findings. The cestode life cycle and implications for zoo collections are discussed. [ABSTRACT FROM AUTHOR]

Plants evolve physical defences, such as spines, against browsing herbivores. However, in some cases, these defences may be anachronistic because the principal consumers of protected parts of the plant are extinct. In such cases, there may be few extant species consuming heavily defended resources. Here we examine the spiny defences of Madagascar's endemic Didiereoideae, and ask whether they may be anachronistic. To accomplish this aim, we reviewed the literature to determine which species consume these plants today, and then used stable isotope biogeochemistry to determine who may have exploited Didiereoideae in the recent past. There are four major groups of browsers that are now extinct in Madagascar: giant lemurs, elephant birds {Aepyornis and Mullerornis: Aepyornithidae), pygmy hippopotamuses {Hippopotamus) and giant tortoises (Aldabrachelys: Testudinidae). Each group was evaluated for isotopic evidence of didiereoid plant consumption. Given the structure of members of this plant clade (especially Alluaudia), we predicted that lemurs would be their most important consumers. Three extant lemur species consume Didiereoideae. Several of the extinct lemurs, particularly Hadropithecus stenognathus, may have relied heavily on these spiny plants. None of the non-lemur megafaunal browsers (elephant birds, hippopotamuses and giant tortoises) were important consumers of Didiereoideae. [ABSTRACT FROM AUTHOR]

Primates are a global conservation priority, with half of known species considered threatened with extinction. Monitoring trends in primate populations is important for identifying species in particular need of conservation action, and evaluating the effectiveness of interventions. Most existing primate survey methods aim to measure abundance. However, obtaining estimates of abundance with acceptable precision to detect changes in population is often expensive and time consuming. Evidence from other taxa suggests that estimating occupancy (the proportion of the area used by the species) may be less resource-intensive, yet still provide useful information for monitoring population trends. We investigate the potential of occupancy modelling for monitoring forest primates using a case study of three species of diurnal lemurs in the eastern rainforest of Madagascar. We estimated detectability and occupancy from a survey with three visits to 30 sites. Our estimates suggest that precision in occupancy estimates would be maximized by visiting a larger number of sites (therefore with limited repeat visits) for Indri indri, whereas the optimal monitoring design for Eulemur fulvus and Propithecus diadema, which showed very low detectability in our surveys, involves more frequent visits to fewer sites. Power analyses suggested that a meaningful reduction in occupancy could be detected with reasonable effort for easily detected species, but the method may prove impractical for more cryptic species. Primates pose a number of practical challenges for occupancy modelling, including choosing appropriate survey designs to satisfy closure assumptions. We suggest that if these issues can be overcome, occupancy modelling has the potential to become a valuable addition to the monitoring toolbox for the study of forest primates. [ABSTRACT FROM AUTHOR]

The lemurs of Madagascar represent a prodigious adaptive radiation. At least 17 species ranging from 11 to 160 kg have become extinct during the past 2000 years. The effect of this loss on contemporary lemurs is unknown. The concept of competitive release favours the expansion of living species into vacant niches. Alternatively, factors that triggered the extinction of some species could have also reduced community-wide niche breadth. Here, we use radiocarbon and stable isotope data to examine temporal shifts in the niches of extant lemur species following the extinction of eight large-bodied species. We focus on southwestern Madagascar and report profound isotopic shifts, both from the time when now-extinct lemurs abounded and from the time immediately following their decline to the present. Unexpectedly, the past environments exploited by lemurs were drier than the protected (albeit often degraded) riparian habitats assumed to be ideal for lemurs today. Neither competitive release nor niche contraction can explain these observed trends. We develop an alternative hypothesis: ecological retreat, which suggests that factors surrounding extinction may force surviving species into marginal or previously unfilled niches. [ABSTRACT FROM AUTHOR]

Abstract: Aye-ayes (Daubentonia madagascerensis) have highly specialized hands with long digits, especially the thin middle one (D3), which is used for extracting food, such as beetle larvae, under bark. Due to the elongation of their fingers, including the thumb, it is presumed that aye-ayes have a rather limited capacity for delicate manipulation of objects. However, studies have reported independent movement of digits D3 and D4, and one report noted a seemingly independent thumb (D1) movement in holding food. Sixteen captive adult aye-ayes were videotaped feeding on a diverse range of foods so as to document how the thumb is used during food holding. To determine if the patterns observed were unique to aye-ayes, 24 individuals from 9 other species of lemurs were also videotaped. Two patterns of thumb use idiosyncratic to aye-ayes and one other lemur, the sifaka (Propithecus verreauxi), were identified: (1) when holding a food item in one hand, the thumb was used to secure the food, with the other digits playing a secondary role; (2) when holding a food item with both hands, the thumbs once again took a predominant role in securing the food. In the majority of these cases, whether held by one or two thumbs, the thumbs curled around the item, but some descriptive evidence is provided that suggests that aye-ayes exaggerate the role of the thumbs by shifting the hold to the outer edge. The novel uses of the thumbs in aye-ayes demonstrate that brain mechanisms can sometimes override the behavioral (or motor) limitations imposed by the morphology of the body. [Copyright &y& Elsevier]

Little is known about ingested food size (Vb) in primates, even though this variable has potentially important effects on food intake and processing. This study provides the first data on Vb in strepsirrhine primates using a captive sample of 17 species. These data can be used for generating and testing models of feeding energetics. Strepsirrhines are of interest because they are hypometabolic and chewing rate and daily feeding time do not show a significant scaling relationship with body size. Using melon, carrot, and sweet potato we found that maximum Vb scales isometrically with body mass and mandible length. Low dietary quality in larger strepsirrhines might explain why Vb increases with body size at a greater rate than does resting metabolic rate. Relative to body size, Vb is large in frugivores but small in folivores; furthermore scaling slopes are higher in frugivores than in folivores. A gross estimate of dietary quality explains much of the variation in Vb that is not explained by body size. Gape adaptations might favor habitually large bites for frugivores and small ones for folivores. More data are required for several feeding variables and for wild populations. [ABSTRACT FROM AUTHOR]

Sexual selection theory predicts that potential mates or competitors signal their quality to conspecifics. Whereas evidence of honest visual or vocal signals in males abounds, evidence of honest signalling via scent or by females is scarce. We previously showed that scent marks in male lemurs seasonally encode information about individual heterozygosity – a reliable predictor of immunocompetence and survivorship. As female lemurs dominate males, compete over resources, and produce sexually differentiated scent marks that likely evolved via direct selection, here we tested whether females also advertise genetic quality via olfactory cues. During the breeding season specifically, individual heterozygosity correlated negatively with the diversity of fatty acids (FAs) expressed in labial secretions and positively with the diversity of heavy FA esters. As odour–gene relationships predictive of health and survivorship emerged during a period critical to mate choice and female competition, we posit that genital scent marks function as honest olfactory ornaments in females. [ABSTRACT FROM AUTHOR]

Lemur grooming has received very little attention in the literature. Nevertheless, allogrooming in lemurs has been suggested to be fundamentally different from the grooming of anthropoids. One reason is that lemurs generally rely on oral rather than manual grooming. Lemur allogrooming has also been suggested to serve less of a social function than has been attributed to anthropoid grooming. I analyzed the allogrooming behaviors of 29 Verreaux's sifaka (Propithecus verreauxi) living in five social groups in the Kirindy Forest of Madagascar. Based upon 1,586 observation hours, I found that sifaka, like anthropoids, spend very little time mutual grooming (2±3%). Half of all allogrooming involved parts of the body that could have been easily groomed by the recipient, such as the limbs. Even though ectoparasite loads are expected to be greater during the rainy season, allogrooming did not increase during the rainy season. Allogrooming rates were influenced by both rank and sex, and increased by 50–100% during the mating season. The results of this study suggest that allogrooming in Verreaux's sifaka plays an important social function, even though it is performed with a toothcomb. Am. J. Primatol. 72:254–261, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The article describes the investigation on the presence of spontaneous hepatocellular carcinoma in captive prosimians. The authors performed a histologic evaluation of suspected proliferative liver lesions and diagnosed hepatocellular carcinoma in 14 of 145 lemurs. They also found that there was no difference between the hepatic iron, molybdenum, or copper in lemurs.

Lemurs are notable for encompassing the range of body-size variation for all primates past and present—close to four orders of magnitude. Benefiting from the phylogenetic proximity of subfossil lemurs to smaller-bodied living forms, we employ allometric data from the skull to probe the ontogenetic bases of size differentiation and morphological diversity across these clades. Building upon prior pairwise comparisons between sister taxa, we performed the first clade-wide analyses of craniomandibular growth allometries in 359 specimens from 10 lemuroids and 176 specimens from 8 indrioids. Ontogenetic trajectories for extant forms were used as a criterion of subtraction to evaluate morphological variation, and putative adaptations among sister taxa. In other words, do species-level differences in skull form result from the differential extension of common patterns of relative growth? In lemuroids, a pervasive pattern of ontogenetic scaling is observed for facial dimensions in all genera, with three genera also sharing relative growth trajectories for jaw proportions (Lemur, Eulemur, Varecia). Differences in masticatory growth and form characterizing Hapalemur and fossil Pachylemur likely reflect dietary factors. Pervasive ontogenetic scaling characterizes the facial skull in extant Indri, Avahi, and Propithecus, as well as their larger, extinct sister taxa Mesopropithecus and Babakotia. Significant interspecific differences are observed in the allometry of indrioid masticatory proportions, with variation in the mechanical advantage of the jaw adductors and stress-resisting elements correlated with diet. As the growth series and adult data are largely coincidental in each clade, interspecific variation in facial form may result from selection for body-size differentiation among sister taxa. Those cases where trajectories are discordant identify potential dietary adaptations linked to variation in masticatory forces during chewing and biting. Although such dissociations highlight selection to uncouple shared ancestral growth patterns, they occur largely via transpositions and retention of primitive size-shape covariation patterns or relative growth coefficients. Am. J. Primatol. 72:161–172, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: In the current study, we determined the seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, Georgia. Serum samples were tested from 52 ring-tailed lemurs (Lemur catta), six blue-eyed black lemurs (Eulemur macaco flavifrons), and four black and white ruffed lemurs (Varecia variegata variegata) using an agglutination assay. Three ring-tailed lemurs (5.8%) were positive for T. gondii (titer of 1:50); one ring-tailed lemur (1.9%) and one black and white ruffed lemur (25%) were positive for S. neurona (titers of 1:1000); and one ring-tailed lemur (1.9%) was positive for E. cuniculi (titer of 1:400). All blue-eyed black lemurs were negative for antibodies to T. gondii, S. neurona, and E. cuniculi. This is the first detection of antibodies to T. gondii in ring-tailed lemurs and antibodies to S. neurona and E. cuniculi in any species of prosimian. [Copyright &y& Elsevier]

Objective To determine the incidence and describe the characteristics of cataracts and other ocular lesions found in two colonies of gray mouse lemurs ( Microcebus murinus). Animals studied A total number of 218 mouse lemurs (age range: 4 months−11 years) were included in this study. All individuals were property of the Muséum National d’Histoire Naturelle (France), and were housed either in Paris (colony #1: 75 animals examined), or in Brunoy (colony #2: 143 animals). Methods Ocular examinations were performed on all animals before and after pupil dilation, and included slit-lamp biomicroscopy and indirect ophthalmoscopy. In both colonies, a limited number of individuals were re-examined between several months and 2 years following the initial eye examinations. The eyes of five mouse lemurs with incipient or immature cataracts that died during this period were collected, and processed for routine histopathologic examination. Results A high incidence of cataracts was observed in both colonies (48% in colony #1; 21% in colony #2). Cataracts were predominantly bilateral, started in the anterior and/or posterior subcapsular area, and appeared to be slowly progressive. The earliest age at which lens opacities were observed was 3.5 years, and more than 50% of mouse lemurs over 7 years of age were diagnosed with cataracts. Complete cataracts led to blindness and were occasionally associated with other ocular lesions. Conclusion We report a high incidence of acquired, slowly progressive, bilateral cataracts in two colonies of mouse lemurs ( Microcebus murinus). Further studies need to be conducted to determine the cause of this disease in this species. [ABSTRACT FROM AUTHOR]

Lemurs kept in captivity have been reported to be highly prone to accumulate excessive amounts of iron in tissues (hemosiderosis). Diagnosis of the condition is most commonly made during a postmortem examination because an antemortem diagnosis requires a liver biopsy, a procedure that may not be well tolerated by all animals. The lack of a noninvasive method to evaluate iron status in captive lemurs limits investigators' ability to effectively screen animals for the presence of hemosiderosis, and to detect the condition early when treatment protocols are most effective. This study was conducted in an effort to provide data regarding iron analyte values in healthy captive lemurs of multiple species. The relationship of various iron-related metabolites was evaluated in 177 clinically normal lemurs of nine different species. Serum iron (sI), total iron binding capacity (TIBC), and ferritin concentration were measured directly and the percent transferrin saturation (TS) was calculated. Significant differences in various iron metabolites were observed among several species, suggesting that normal reference values for iron metabolites in lemurs may need to be developed on a species by species basis. Am. J. Primatol. 68:1–13, 2006. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Behavioral and neurophysiological studies strongly suggest that visual orienting reflects the integration of sensory, motor, and motivational variables. Relatively little is known, however, regarding the goals that govern visual orienting of animals in their natural environments. Field observations suggest that most nonhuman primates orient to features of their natural environments whose salience is dictated by the visual demands of foraging, locomotion, and social interaction. This hypothesis is difficult to test quantitatively, however, in part because accurate gaze-tracking technology has not been employed in field studies. We here report the implementation of a new, telemetric, infrared-video gaze-tracker to measure visual orienting in freely moving, socially housed prosimian primates (Lemur catta). Two male lemurs tolerated the system at approximately 1/4 body weight, permitting successful measurements of gaze behavior during spontaneous locomotion through both terrestrial and arboreal landscapes, and in both social and asocial environments. [Copyright &y& Elsevier]

Abstract: Measuring the body temperature of animals living under natural conditions has gained increasing interest. This study shows in the small lemur Cheirogaleus medius that for many questions external collar transmitters can constitute an excellent alternative to implanted transmitters. During both active as well as inactive phases, data from collar transmitters precisely reflect core body temperature over a wide range of ambient temperatures. Even minor changes in the body temperature are detected, and collar transmitters are very adequate for determining general patterns of body temperature and activity in suitable species. [Copyright &y& Elsevier]

Partial exon 2 sequences (202 bp) of the lemur Mhc-DRB genes were sequenced. A total of 137 novel sequences were detected in 66 lemurs, representing four out of the five extant families. Trans-species polymorphisms and even identical sequences were observed not only among genera but also among families. Based on the time-scale of lemur evolution, these findings suggest that some identical sequences have been maintained for more than 40 million years. This is in contrast to the evolutionary mode of simian DRB genes, where such identical sequences have been retained for at most several million years. To explore the reasons behind these unexpected findings, the degree of recombination and the synonymous substitution rate in lemurs and simians were examined. We found that (1) little difference existed in the extent of recombination, (2) frequent recombination occurred within the α-helix as well as between the β-pleated sheet and the α-helix, and (3) the synonymous substitution rate was significantly reduced in lemur lineages. Upon phylogenetic analysis, lemur DRB genes were clustered by themselves and separated from the other primate DRB genes (simians and non-Malagasy prosimians). This result suggests that the DRB variations in extant lemur populations have been generated after the divergence of the lemurs from the remaining primates. This mode of substitution accumulation is also supported by a pattern of mismatch distribution among lemur DRB genes. These observations correspond with the postulation that a severe bottleneck occurred when the ancestors of lemurs settled into Madagascar from the African continent. [ABSTRACT FROM AUTHOR]

Lemur catta Troop D at Berenty Reserve has been studied intermittently for 35 years. During 90 hours of continuous sampling in August 1998, I observed and mapped troop movement and scent marking. I compared these observations with data from June, 1975. The core of Troop D1's 1998 home range is the same as for Troop D in 1975. Sixty-two percent of Troop D1's time in 1998 was spent in the 1975 home range, and 52% of their scent marks were placed in that 1975 home range. The remainder of their time was spent in an extension of their home range, which is now an area of confrontation with an adjacent troop. They used the same sleeping trees in the 2 years, and all of the 1998 scent marks deposited in the 1975 home range were placed in the same locations marked in 1975. The similarities in their use of space in 1975 and 1998 were remarkable. [ABSTRACT FROM AUTHOR]