Search

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]

Copyright of Biodiversity & Conservation is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El objetivo de este trabajo es proporcionar información acerca del diagnóstico y del manejo médico de Toxoplasma gondii asociado a un plantel mixto de 5 lémures cola anillada (2 hembras y 3 machos) bajo cuidado humano en una colección zoológica en la 6ta región de Chile. Se presentan signos reproductivos en la hembra de lémur cola anillada matriarca de 8 años, con fiebre, decaimiento, apatía, anorexia y aborto de un neonato a término. Se realiza examen clínico, perfil hematológico, bioquímico y serología de enfermedades infecciosas en la madre bajo anestesia. Se realizan estudios serológicos e histopatológicos en la cría abortada. Los resultados evidencian infección por toxoplasma gondii a nivel central en la cría sin otra evidencia científica. La literatura consultada evidencia que los lémures son una de las especies más susceptibles a esta enfermedad y que muchas veces el diagnóstico es engorroso. Luego de 6 años sin concebir crías en la colección, se logró concebir un ejemplar sano.

Abstract The loss and degradation of forests and other ecosystems worldwide threaten both global biodiversity and the livelihoods of people who use natural resources. Understanding how natural resource use impacts landscape provisioning services for both people and wildlife is thus critical for designing comprehensive resource management strategies. We used data from community focus groups, botanical plots and an inventory of plant species consumed by the Critically Endangered red‐ruffed lemur (Varecia rubra) to assess the availability of key provisioning services for people and endemic wildlife on the Masoala Peninsula, a rainforest transformation landscape, in northeastern Madagascar (Masoala National Park and 13 surrounding communities). We constructed Poisson regression mixed models to evaluate the impact of community factors (i.e. community population size, plot distance to community) and changes over time on the count and species richness of timber trees, medicinal plants and red‐ruffed lemur food trees within botanical plots. Over three‐quarters of all plant species could be used for at least one purpose by local communities (n = 238 species). Of the 59 V. rubra food tree species, only 15% had no reported human use. Timber and ruffed lemur food tree availability declined both with community population size and time and were predicted to be lower outside of Masoala National Park. In contrast, medicinal plant availability was not strongly predicted by any tested factors. Provisioning service availability also differed strongly across sites, suggesting that additional, untested proxies of human pressure likely also have an effect. Our results highlight the importance of evaluating natural resource availability from a community‐based perspective and by resource purpose to inform forest landscape restoration efforts that can support both people and wildlife. Read the free Plain Language Summary for this article on the Journal blog.

Primates are adept at dealing with fluctuating availability of resources and display a range of responses to minimize the effects of food scarcity. An important component of primate conservation is to understand how primates adapt their foraging and ranging patterns in response to fluctuating food resources. Animals optimize resource acquisition within the home range through the selection of resource‐bearing patches and choose between contrasting foraging strategies (resource‐maximizing vs. area‐minimizing). Our study aimed to characterize the foraging strategy of a folivorous primate, Verreaux's sifaka (Propithecus verreauxi), by evaluating whether group home range size varied between peak and lean leaf seasons within a seasonally dry tropical forest in Madagascar. We hypothesized that Verreaux's sifaka used the resource maximization strategy to select high‐value resource patches so that during periods of resource depression, the home range area did not significantly change in size. We characterized resource availability (i.e., primary productivity) by season at Kirindy Mitea National Park using remotely‐sensed Enhanced Vegetation Index data. We calculated group home ranges using 10 years of focal animal sampling data collected on eight groups using both 95% and 50% kernel density estimation. We used area accumulation curves to ensure each group had an adequate number of locations to reach seasonal home range asymptotes. Neither 95% home ranges nor 50% core areas differed across peak and lean leaf resource seasons, supporting the hypothesis that Verreaux's sifaka use a resource maximization strategy. With a better understanding of animal space use strategies, managers can model anticipated changes under environmental and/or anthropogenic resource depression scenarios. These findings demonstrate the value of long‐term data for characterizing and understanding foraging and ranging patterns. We also illustrate the benefits of using satellite data for characterizing food resources for folivorous primates. Research Highlights: While seasonal leaf availability (characterized using Enhanced Vegetation Index) differed between peak and lean leaf seasons, we found no significant variation in home range and core area sizes of Verreaux's sifaka groups at Kirindy Mitea National Park, Madagascar.Our findings suggest Verreaux's sifaka use a resource‐maximizing strategy.Home range area estimates are improved when an asymptote analysis is used to ensure an adequate number of location samples and when temporal requirements are imposed to avoid concentrated sampling. [ABSTRACT FROM AUTHOR]

Hibernation is a widespread metabolic strategy among mammals for surviving periods of food scarcity. During hibernation, animals naturally alternate between metabolically depressed torpor bouts and energetically expensive arousals without ill effects. As a result, hibernators are promising models for investigating mechanisms that buffer against cellular stress, including telomere protection and restoration. In non-hibernators, telomeres, the protective structural ends of chromosomes, shorten with age and metabolic stress. In temperate hibernators, however, telomere shortening and elongation can occur in response to changing environmental conditions and associated metabolic state. We investigate telomere dynamics in a tropical hibernating primate, the fat-tailed dwarf lemur (Cheirogaleus medius). In captivity, these lemurs can hibernate when maintained under cold temperatures (11–15 °C) with limited food provisioning. We study telomere dynamics in eight fat-tailed dwarf lemurs at the Duke Lemur Center, USA, from samples collected before, during, and after the hibernation season and assayed via qPCR. Contrary to our predictions, we found that telomeres were maintained or even lengthened during hibernation, but shortened immediately thereafter. During hibernation, telomere lengthening was negatively correlated with time in euthermia. Although preliminary in scope, our findings suggest that there may be a preemptive, compensatory mechanism to maintain telomere integrity in dwarf lemurs during hibernation. Nevertheless, telomere shortening immediately afterward may broadly result in similar outcomes across seasons. Future studies could profitably investigate the mechanisms that offset telomere shortening within and outside of the hibernation season and whether those mechanisms are modulated by energy surplus or crises. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Predicting future conservation needs can help inform conservation management but is subject to uncertainty. We measured deforestation rates during 2015–2017 for 114 protected areas in Madagascar, linked deforestation to the status of protection according to IUCN categories I–VI, used recent deforestation rates to extrapolate forest cover over 2017–2050 and linked the size of forest blocks to the projected persistence of lemur subpopulations. In the six IUCN categories for protected areas in Madagascar the median size of forest blocks is 9–37 km2 and median annual deforestation rates range from 0.02% in the single IUCN category III site to 0.19% in category II and 1.95% in category VI sites. In 2017, 40% of all forest blocks within protected areas were < 10 km2, and this is projected to increase to 45% in 2050. Apart from these small forest fragments, the modal site of forest blocks was 160–320 km2 in 2017, and this is projected to decrease to 80–160 km2 in 2050. The range of > 50% of all lemur species exclusively contains forest blocks of < 10 km2. The modal size of forest blocks > 10 km2 is predicted to remain at 120 km2 until 2050. Although uncertainty remains, these analyses provide hope that forest blocks within the protected areas of Madagascar will remain large enough to maintain lemur subpopulations for most species until 2050. This should allow sufficient time for the implementation of effective conservation measures.

Predicting future conservation needs can help inform conservation management but is subject to uncertainty. We measured deforestation rates during 2015–2017 for 114 protected areas in Madagascar, linked deforestation to the status of protection according to IUCN categories I–VI, used recent deforestation rates to extrapolate forest cover over 2017–2050 and linked the size of forest blocks to the projected persistence of lemur subpopulations. In the six IUCN categories for protected areas in Madagascar the median size of forest blocks is 9–37 km2 and median annual deforestation rates range from 0.02% in the single IUCN category III site to 0.19% in category II and 1.95% in category VI sites. In 2017, 40% of all forest blocks within protected areas were < 10 km2, and this is projected to increase to 45% in 2050. Apart from these small forest fragments, the modal site of forest blocks was 160–320 km2 in 2017, and this is projected to decrease to 80–160 km2 in 2050. The range of > 50% of all lemur species exclusively contains forest blocks of < 10 km2. The modal size of forest blocks > 10 km2 is predicted to remain at 120 km2 until 2050. Although uncertainty remains, these analyses provide hope that forest blocks within the protected areas of Madagascar will remain large enough to maintain lemur subpopulations for most species until 2050. This should allow sufficient time for the implementation of effective conservation measures. [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]

Aims: Indri indri is a lemur of Madagascar which is critically endangered. The analysis of the microbial ecology of the intestine offers tools to improve conservation efforts. This study aimed to achieve a functional genomic analysis of three Lactiplantibacillus plantarum isolates from indris. Methods and results: Samples were obtained from 18 indri; 3 isolates of Lp. plantarum were obtained from two individuals. The three isolates were closely related to each other, with <10 single nucleotide polymorphisms, suggesting that the two individuals shared diet-associated microbes. The genomes of the three isolates were compared to 96 reference strains of Lp. plantarum. The three isolates of Lp. plantarum were not phenotypically resistant to antibiotics but shared all 17 genes related to antimicrobial resistance that are part of the core genome of Lp. plantarum. The genomes of the three indri isolates of Lp. plantarum also encoded for the 6 core genome genes coding for enzymes related to metabolism of hydroxybenzoic and hydroxycinnamic acids. The phenotype for metabolism of hydroxycinnamic acids by indri isolates of Lp. plantarum matched the genotype. Conclusions: Multiple antimicrobial resistance genes and gene coding for metabolism of phenolic compounds were identified in the genomes of the indri isolates, suggesting that Lp. plantarum maintains antimicrobial resistance in defense of antimicrobial plant secondary pathogens and that their metabolism by intestinal bacteria aids digestion of plant material by primate hosts. [ABSTRACT FROM AUTHOR]

Identifying the major forces driving variation in gut microbiomes enhances our understanding of how and why symbioses between hosts and microbes evolved. Gut prokaryotic community variation is often closely associated with host evolutionary and ecological variables. Whether these same factors drive variation in other microbial taxa occupying the animal gut remains largely untested. Here, we present a one-to-one comparison of gut prokaryotic (16S rRNA metabarcoding) and microeukaryotic (18S rRNA metabarcoding) community patterning among 12 species of wild lemurs. Lemurs were sampled from dry forests and rainforests of southeastern Madagascar and display a range of phylogenetic and ecological niche diversity. We found that while lemur gut prokaryotic community diversity and composition vary with host taxonomy, diet, and habitat, gut microeukaryotic communities have no detectable association with any of these factors. We conclude that gut microeukaryotic community composition is largely random, while gut prokaryotic communities are conserved among host species. It is likely that a greater proportion of gut microeukaryotic communities comprise taxa with commensal, transient, and/or parasitic symbioses compared with gut prokaryotes, many of which form long-term relationships with the host and perform important biological functions. Our study highlights the importance of greater specificity in microbiome research; the gut microbiome contains many "omes" (e.g., prokaryome, eukaryome), each comprising different microbial taxa shaped by unique selective pressures. [ABSTRACT FROM AUTHOR]

Simple Summary: Lemur hunting and consumption is widespread in Madagascar. Understanding what drives this phenomenon is key to conserving lemurs and protecting human livelihoods. Current research shows poverty to be a primary driver of lemur hunting and consumption, but no study has employed a composite poverty metric that includes health, education, and living standards. Our study employs such a metric, along with income, to investigate, for the first time, poverty as a driver of lemur hunting and consumption in and around Kirindy Mitea National Park, Madagascar. We document alarming levels of poverty and lemur hunting and consumption among the study community but find no relationship between the variables. Because nearly all households in the study community were impoverished, possible explanations include the following: (1) poverty is not a driver of lemur hunting and consumption in Kirindy Mitea National Park, or (2) a relationship could not be found due to the socio-economic similarity of households in our study community. We consider both interpretations in light of the current literature and offer recommendations for future research. If human and non-human primates are to continue to co-exist in and around Kirindy Mitea National Park, immediate investment in poverty eradication is required, and conservationists should test the efficacy of livestock interventions locally. The futures of human and nonhuman primates are closely tied in protected areas. Understanding this interconnectedness is especially urgent in Madagascar, one of the world's most impoverished biodiversity hotspots. Yet, no study has evaluated the relationship between poverty and lemur hunting and consumption using a composite poverty metric that includes health, education, and living standards. To address this gap, and to inform primate conservation practice and policy, we administered annual surveys to 81 households over six consecutive months (September 2018 to March 2019) in a village on the border of Kirindy Mitea National Park, Madagascar. We observed extreme deprivation scores across multiple dimensions of poverty and identified ninety-five percent of households as 'impoverished'. Of these, three-quarters (77%) of households were identified as being in 'severe poverty'. One-fifth (19%) of all households hunted lemurs and half (49%) of households consumed lemurs. While poverty eradication is an urgent need in communities around Kirindy Mitea National Park, our findings show no relationship between poverty and lemur hunting and consumption, perhaps due to the lack of variance in poverty. Our results highlight the need to investigate other contributory factors to lemur hunting and consumption locally. Because food insecurity is a known driver of lemur hunting and consumption among the study community, and because domestic meats can be preferred over protected species, we recommend testing the efficacy of livestock interventions near Kirindy Mitea National Park. [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]

Captive wildlife benefit from ecologically informed management strategies that promote natural behaviors. The Duke Lemur Center has pioneered husbandry programs rooted in species' ecology for a diversity of lemurs, including housing social groups in multiacre forest enclosures. We systematically document the foraging and ranging patterns of Coquerel's sifakas (Propithecus coquereli) living in these forest enclosures. Coquerel's sifakas are seasonal frugo‐folivores that exhibit striking feeding flexibility in the wild. They are also one of the few members of the Indriidae family to persist in captivity. During all‐day follows in the spring and summer of 2 consecutive years, we tracked the behavior of 14 sifakas in six forest enclosures. The sifakas' ranging and foraging patterns reflected those of wild sifakas in western Madagascar: On average, DLC sifakas occupied 3‐day home ranges of 1.2 ha, traveled 473 m/day, and spent 26% of their time foraging for wild foodstuffs. The sifakas foraged most for young and mature leaves, fruits, nuts, and flowers from 39 plant species, especially red maple (Acer rubrum), tulip poplar (Liriodendron tulipifera), black locust (Robinia pseudoacacia), grapevine (Vitis rotundifolia), hickory (Carya spp.), and white oak (Quercus alba). Foraging patterns varied across seasons, enclosure areas, and groups, potentially reflecting differences in phenology, microhabitats, and individual preferences. While demonstrating that captive‐bred primates express wild‐like behaviors under ecologically relevant conditions, our results underscore the feeding flexibility of the Coquerel's sifaka. Captive wildlife exhibiting the range of species‐specific behaviors are key resources for ecological research and might be best suited for future reintroductions. Research Highlights: Captive Coquerel's sifakas maintained in large forest enclosures at the Duke Lemur Center display ranging and foraging patterns that reflect those of wild sifaka species in western Madagascar. Sifakas occupied 3‐day home ranges of 1.2 ha and spent 26% of their time foraging for a seasonal frugo‐folivorous diet of young and mature leaves, fruits, nuts, flowers, petioles, and bark from minimally 39 plant species. Husbandry efforts can beneficially incorporate ecological research to maintain captive wildlife under conditions that promote animal health while improving research and conservation goals. [ABSTRACT FROM AUTHOR]

Animal abundance is determined by a number of factors, including vegetation structure, food availability and quality, human activities, predation risk, and disease. Vegetation structure, food availability, and human activity often are used to guide conservation efforts, such as protected area zoning and reforestation, especially for primates. We sought to determine whether Critically Endangered golden-crowned sifaka (Propithecus tattersalli) densities could be predicted across a heterogeneous landscape as a function of vegetation structure, food availability, and human activity. We conducted walking transect surveys across the sifakas' entire global range in Loky-Manambato Protected Area of Madagascar from 2016–2018, expanding upon a study conducted in 2006/2008. Potential predictors of sifaka density included metrics of vegetation structure (e.g., tree density, forest type), food availability (e.g., food tree basal area, normalized difference vegetation index (NDVI)), and human activity (e.g., tree cutting, livestock grazing). Low-intensity tree cutting and wet season NDVI were the best, positive predictors of sifaka densities. Sifaka densities within study units across their restricted range (880 km2) were highly variable (range: 6.8–78.1 sifakas/km2), emphasizing the importance of large-scale study designs across all suitable land cover types for assessing a species' abundance, regardless of its area of occupancy. We estimated that 10,222–12,631 sifakas remain. Based on previous surveys, this indicates that populations either remained stable over the past 20 years or have declined by 30–43% in the past 10 years; we argue that a decline is most likely based on our updating of forest cover estimates for both of the prior studies. We also found that wet season NDVI is a positive predictor of sifaka densities, which will aid managers in prioritizing conservation actions in this region using widely available remotely sensed data. [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]

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 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.

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]

We performed a retrospective examination of spontaneous hepatocellular carcinomas (HCCs) (primary and metastatic tumors) in 14 captive prosimians brought to the Veterinary Medical Diagnostic Laboratory in North Carolina State University over a period of 11 years (2003 to 2014) to characterize the tumors. These animals are endangered primates; a better understanding of the main fatal neoplasms is crucial. In addition to the histologic evaluation, an immunohistochemical study was also performed, using a hepatocyte marker (hepatocyte paraffin 1 [HepPar-1]) and 2 cholangiocyte markers (keratin 7 [K7] and keratin 19 [K19]), in an attempt to identify a specific profile for HCCs with metastatic behavior. Six of the 14 HCCs had pulmonary metastases. The most frequent histopathological findings were a trabecular pattern (14/14, 100%), presence of multinucleated cells (12/14, 85.7%), and foci of extramedullary hematopoiesis (9/14, 64.3%). The mitotic count was significantly higher in the metastatic HCCs (P <.05). HepPar-1 was detected in all primary and metastatic HCCs, with a strong intensity of staining. Labeling for K7 and K19 was positive in 12 HCCs (85.7%) and 1 HCC (7.1%), respectively. Contrary to the less aggressive HCCs, most of the metastatic HCCs (5/6) expressed K7 in more than 15% of cells. The percentage of K7-positive neoplastic hepatocytes was significantly higher in metastatic HCCs. This study suggests that K7 might be a prognostically relevant marker in HCCs of captive prosimians. [ABSTRACT FROM AUTHOR]

In 1967 G.G. Simpson described three partial mandibles from early Miocene deposits in Kenya that he interpreted as belonging to a new strepsirrhine primate, Propotto. This interpretation was quickly challenged, with the assertion that Propotto was not a primate, but rather a pteropodid fruit bat. The latter interpretation has not been questioned for almost half a century. Here we re-evaluate the affinities of Propotto, drawing upon diverse lines of evidence to establish that this strange mammal is a strepsirrhine primate as originally suggested by Simpson. Moreover, our phylogenetic analyses support the recognition of Propotto, together with late Eocene Plesiopithecus from Egypt, as African stem chiromyiform lemurs that are exclusively related to the extant aye-aye (Daubentonia) from Madagascar. Our results challenge the long-held view that all lemurs are descended from a single ancient colonization of Madagascar, and present an intriguing alternative scenario in which two lemur lineages dispersed from Africa to Madagascar independently, possibly during the later Cenozoic.

A red ruffed lemur (Varecia rubra) from a zoo in Louisiana, USA, was euthanized for worsening paresis. Brain and spinal cord histology identified eosinophilic meningoencephalomyelitis with intralesional adult Angiostrongylus sp. nematodes. PCR and sequencing confirmed A. cantonensis infection, indicating this parasite constitutes an emerging zoonosis in the southeastern United States.

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]

Parent-offspring interactions are essential to interpret animal social evolution and behavior, but their role in mediating acoustic communication in animals that interact vocally is still unclear. Increasing evidence shows that primate vocal communication is way more flexible than previously assumed, and research on this topic can provide further information on how the social environment shaped vocal plasticity during the evolution of the Primate order. Indris communicate through elaborated vocal emissions, usually termed songs. Songs are interactive vocal displays in which all members of the family group alternate their emissions, taking turns during chorusing events. We aimed to understand whether specific rules regulate the turn-taking of different group members and investigate the flexibility of indris’ vocal behavior when co-singing with their offspring. We found that social factors can influence the turn-taking organization in a chorus, as offspring were more likely to drop out from the parents’ duet than join in, and we speculate that overlap might signal competition by members of the same-sex. The duet between the reproductive pair was the most common type of singing organization, followed by a duet between mothers and sons and the triadic interaction between mother, father, and son. Interestingly, parents’ solo singing seems to stimulate offspring to vocalize, and we also found that mothers and fathers simplify, at least in part, song elaboration when chorusing with offspring. Our results indicate that indris can perform short-time adjustments to the number of co-emitters and their identity: our approach is advantageous in highlighting the multilevel influences on primate vocal flexibility. Moreover, it provides evidence that some aspects of our vocal plasticity were already present in the lemur lineage.

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]

Abstract 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 Background Captive animals, compared to their wild counterparts, generally harbor imbalanced gut microbiota owing, in part, to their altered diets. This imbalance is particularly striking for folivores that fundamentally rely on gut microbiota for digestion, yet rarely receive sufficient dietary fiber in captivity. We examine the critically endangered Coquerel’s sifaka (Propithecus coquereli), an anatomically specialized, rather than facultative, folivore that consumes a seasonal frugo-folivorous diet in the wild, but is provisioned predominantly with seasonal foliage and orchard vegetables in captivity. Using amplicon and metagenomic sequencing applied to fecal samples collected from two wild and one captive population (each comprising multiple groups), we clarify how dietary variation underlies the perturbational effect of captivity on the structure and function of this species’ gut microbiota. Results The gut microbiota of wild sifakas varied by study population, most notably in community evenness and in the abundance of diet-associated microbes from Prevotellaeceae and Lachnospiraceae. Nevertheless, the differences among wild subjects were minor compared to those evident between wild and captive sifakas: Unusually, the consortia of captive sifakas were the most diverse, but lacked representation of endemic Bacteroidetes and metagenomic capacity for essential amino-acid biosynthesis. Instead, they were enriched for complex fiber metabolizers from the Firmicutes phylum, for archaeal methanogens, and for several metabolic pathways putatively linked to plant fiber and secondary compound metabolism. Conclusions The relatively minor differences in gut microbial structure and function between wild sifaka populations likely reflect regional and/or temporal environmental variability, whereas the major differences observed in captive conspecifics, including the loss of endemic microbes, but gain in low-abundance taxa, likely reflect imbalanced or unstable consortia. Indeed, community perturbation may not necessarily entail decreased community diversity. Moreover, signatures of greater fiber degradation indicate that captive sifakas consume a more fibrous diet compared to their wild counterparts. These results do not mirror those typically reported for folivores and herbivores, suggesting that the direction and strength of captivity-induced ‘dysbiosis’ may not be universal across species with similar feeding strategies. We propose that tailored, species-specific dietary interventions in captivity, aimed at better approximating naturally foraged diets, could functionally ‘rewild’ gut microbiota and facilitate successful management of diverse species.

Female mammals employ reproductive strategies (e.g., internal gestation) that result in power asymmetries specific to intersexual dyads. Because the number of eggs available for fertilization at any given time for most mammals is quite limited, having a fertilizable egg is potentially an important source of economic power for females. Control over mating opportunities is a source of intersexual leverage for female Verreaux’s sifaka (Propithecus verreauxi). We examined economic factors thought to influence the value of mating opportunities, and, thus, the extent of female leverage: kinship and market effects. Using a longitudinal dataset of agonistic interactions collected during focal animal sampling of all adult individuals in 10 social groups from 2008 to 2019, we tested the effects of relatedness, female parity, reproductive season, and adult sex ratio (population and group) on (1) the direction of submissive signaling and (2) which sex won a contested resource. While 96% of the acts of submission were directed from males toward females, females only won a third of their conflicts with males. Thus, our study has implications for evolutionary explanations of female-biased power. If female power evolved due to their greater need for food and other resources, then intersexual conflicts would be expected to result in males more consistently relinquishing control of resources. As expected, males were more likely to chatter submissively toward successful mothers, during the mating season, and when the sex ratio was male-biased. Although females generally had less power to win a conflict when their fertilizable egg was less valuable (when they were nulliparous or unsuccessful mothers or when interacting with male kin) and with an increasing female-bias in the sex ratio, this ability to win additionally was influenced by which sex initiated the conflict. Our study demonstrates that female leverage can be influenced by the supply and demand for mating opportunities, but evoking submission does not translate into winning a resource. Indeed, intersexual power is dynamic, contextual, and dependent on the individuals in the dyad.

The critically endangered indri (Indri indri) is the largest extant lemur species and its population size is projected to decline over the next three generations due to habitat loss, hunting and climate change. Accurate information on the demographic parameters driving the population dynamics of indri is urgently needed to help decision-making regarding the conservation of this iconic species. We monitored and followed the life histories of 68 individually recognizable indris in 10 family groups in the Maromizaha New Protected Area (Madagascar) for 12 years. We estimated age and sex-specific survival trajectories using a Bayesian hierarchical survival model and found that the survival curves for male and female indris show a similar pattern, consistent with what found typically in primates; i.e., a high infant mortality rate which declines with age in the juvenile phase and increases again for adults. Also, life expectancies at 2 years of age (e2), were found to be similar between the sexes (e2 females = 7.8 years; e2 males = 7.5 years). We suggest that the lack of strong differences in the survival patterns for male and female indris are related to the strictly monogamous mating system and the lack of sexual dimorphism in this species. Our study provides, for the first time, robust estimates for demographic parameters of indris and one of the very few datasets on survival trajectories available for primates.

The cestode Hymenolepis nana is a common parasite of humans and mice. Fecal shedding in the absence of clinical disease has previously been reported in ring-tailed lemurs (Lemur catta). This report describes fatal, disseminated H. nana cestodiasis infection in an aged ring-tailed lemur in a zoological collection. The parasites were associated with severe multifocal to coalescing and regionally extensive pyogranulomatous hepatitis and moderate multifocal pneumonia. The morphology of the parasites was highly unusual. Profiles were variably sized, ellipsoid to irregularly serpiginous, lined by a thin tegument, and filled with lightly eosinophilic fibrillar stroma and numerous, round basophilic cells. Polymerase chain reaction targeting a portion of the 18S rRNA gene and DNA sequencing of the amplicon showed 100% homology with H. nana. [ABSTRACT FROM AUTHOR]

Primates acquire gut microbiota from conspecifics through direct social contact and shared environmental exposures. Host behaviour is a prominent force in structuring gut microbial communities, yet the extent to which group or individual‐level forces shape the long‐term dynamics of gut microbiota is poorly understood. We investigated the effects of three aspects of host sociality (social groupings, dyadic interactions, and individual dispersal between groups) on gut microbiome composition and plasticity in 58 wild Verreaux's sifaka (Propithecus verreauxi) from six social groups. Over the course of three dry seasons in a 5‐year period, the six social groups maintained distinct gut microbial signatures, with the taxonomic composition of individual communities changing in tandem among coresiding group members. Samples collected from group members during each season were more similar than samples collected from single individuals across different years. In addition, new immigrants and individuals with less stable social ties exhibited elevated rates of microbiome turnover across seasons. Our results suggest that permanent social groupings shape the changing composition of commensal and mutualistic gut microbial communities and thus may be important drivers of health and resilience in wild primate populations. [ABSTRACT FROM AUTHOR]

The critically endangered indri (Indri indri) is the largest extant lemur species and its population size is projected to decline over the next three generations due to habitat loss, hunting and climate change. Accurate information on the demographic parameters driving the population dynamics of indri is urgently needed to help decision-making regarding the conservation of this iconic species. We monitored and followed the life histories of 68 individually recognizable indris in 10 family groups in the Maromizaha New Protected Area (Madagascar) for 12 years. We estimated age and sex-specific survival trajectories using a Bayesian hierarchical survival model and found that the survival curves for male and female indris show a similar pattern, consistent with what found typically in primates; i.e., a high infant mortality rate which declines with age in the juvenile phase and increases again for adults. Also, life expectancies at 2 years of age (e2), were found to be similar between the sexes (e2 females = 7.8 years; e2 males = 7.5 years). We suggest that the lack of strong differences in the survival patterns for male and female indris are related to the strictly monogamous mating system and the lack of sexual dimorphism in this species. Our study provides, for the first time, robust estimates for demographic parameters of indris and one of the very few datasets on survival trajectories available for primates. [ABSTRACT FROM AUTHOR]

The urgent need for effective wildlife monitoring solutions in the face of global biodiversity loss has resulted in the emergence of conservation technologies such as passive acoustic monitoring (PAM). While PAM has been extensively used for marine mammals, birds, and bats, its application to primates is limited. Black-and-white ruffed lemurs (Varecia variegata) are a promising species to test PAM with due to their distinctive and loud roar-shrieks. Furthermore, these lemurs are challenging to monitor via traditional methods due to their fragmented and often unpredictable distribution in Madagascar's dense eastern rainforests. Our goal in this study was to develop a machine learning pipeline for automated call detection from PAM data, compare the effectiveness of PAM versus in-person observations, and investigate diel patterns in lemur vocal behavior. We did this study at Mangevo, Ranomafana National Park by concurrently conducting focal follows and deploying autonomous recorders in May-July 2019. We used transfer learning to build a convolutional neural network (optimized for recall) that automated the detection of lemur calls (57-h runtime; recall = 0.94, F1 = 0.70). We found that PAM outperformed in-person observations, saving time, money, and labor while also providing re-analyzable data. Using PAM yielded novel insights into V. variegata diel vocal patterns; we present the first published evidence of nocturnal calling. We developed a graphic user interface and open-sourced data and code, to serve as a resource for primatologists interested in implementing PAM and machine learning. By leveraging the potential of this pipeline, we can address the urgent need for effective primate population surveys to inform conservation strategies., (© 2024 The Authors. American Journal of Primatology published by Wiley Periodicals LLC.)

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.

In tropical Africa, wild meat consumption by rural communities who live in or near protected areas can be a major challenge in the conservation of threatened species. Lemurs and the fossa are among the species consumed in Makira Natural Park, Madagascar. Because of their low reproductive rates and the high human population density, these species are known to be hunted unsustainably. We estimated the prevalence of lemur and fossa meat consumption in villages within and around Makira Natural Park using an indirect questioning method, the unmatched count technique (UCT), and compared it with results from direct questioning. The UCT revealed that 53.0% of households had eaten lemur meat over the previous year (95% confidence interval [CI]: 42.0–64.1%) and 24.2% had eaten fossa meat (95% CI: 14.2–34.2%). The percentage of households that ate lemur meat estimated through the UCT was more than 3.3 times higher than that obtained from direct questioning, and 12 times higher for fossa. Our estimates will be used to define the scale needed for a behavior change campaign to be conducted in the study area and will serve as a baseline to assess the impact of conservation activities aimed at reducing the consumption of lemurs and fossas. [ABSTRACT FROM AUTHOR]

Many histological techniques are used to identify and characterize myelin in the mammalian nervous system. Due to the high content of lipids in myelin sheaths, coherent anti-stokes Raman scattering (CARS) microscopy is a label-free method that allows identifying myelin within tissues. CARS excites the CH2 vibrational mode at 2845 cm−1 and CH2 bonds are found in lipids. In this study, we have used CARS for a new biological application in the field of spinal cord analysis. We have indeed compared several parameters of spinal cord myelin sheath in three different species, i.e., mouse, lemur, and human using a label-free method. In all species, we analyzed the dorsal and the lateral funiculi of the adult thoracic spinal cord. We identified g-ratio differences between species. Indeed, in both funiculi, g-ratio was higher in mice than in the two primate species, and the myelin g-ratio in lemurs was higher than in humans. We also detected a difference in g-ratio between the dorsal and the lateral funiculi only in humans. Furthermore, species differences between axon and fiber diameters as well as myelin thickness were observed. These data may reflect species specificities of conduction velocity of myelin fibers. A comparison of data obtained by CARS imaging and fluoromyelin staining, a method that, similar to CARS, does not require resin embedding and dehydration, displays similar results. CARS is, therefore, a label-free alternative to other microscopy techniques to characterize myelin in healthy and neurological disorders affecting the spinal cord.

The overuse of man-made antibiotics has facilitated the global propagation of antibiotic resistance genes in animals, across natural and anthropogenically disturbed environments. Although antibiotic treatment is the most well-studied route by which resistance genes can develop and spread within host-associated microbiota, resistomes also can be acquired or enriched via more indirect routes, such as via transmission between hosts or via contact with antibiotic-contaminated matter within the environment. Relatively little is known about the impacts of anthropogenic disturbance on reservoirs of resistance genes in wildlife and their environments. We therefore tested for (a) antibiotic resistance genes in primate hosts experiencing different severities and types of anthropogenic disturbance (i.e., non-wildlife animal presence, human presence, direct human contact, and antibiotic treatment), and (b) covariation between host-associated and environmental resistomes. We used shotgun metagenomic sequencing of ring-tailed lemur (Lemur catta) gut resistomes and associated soil resistomes sampled from up to 10 sites: seven in the wilderness of Madagascar and three in captivity in Madagascar or the United States. We found that, compared to wild lemurs, captive lemurs harbored greater abundances of resistance genes, but not necessarily more diverse resistomes. Abundances of resistance genes were positively correlated with our assessments of anthropogenic disturbance, a pattern that was robust across all ten lemur populations. The composition of lemur resistomes was site-specific and the types of resistance genes reflected antibiotic usage in the country of origin, such as vancomycin use in Madagascar. We found support for multiple routes of ARG enrichment (e.g., via human contact, antibiotic treatment, and environmental acquisition) that differed across lemur populations, but could result in similar degrees of enrichment. Soil resistomes varied across natural habitats in Madagascar and, at sites with greater anthropogenic disturbance, lemurs and soil resistomes covaried. As one of the broadest, single-species investigations of wildlife resistomes to date, we show that the transmission and enrichment of antibiotic resistance genes varies across environments, thereby adding to the mounting evidence that the resistance crisis extends outside of traditional clinical settings.

Abstract In tropical Africa, wild meat consumption by rural communities who live in or near protected areas can be a major challenge in the conservation of threatened species. Lemurs and the fossa are among the species consumed in Makira Natural Park, Madagascar. Because of their low reproductive rates and the high human population density, these species are known to be hunted unsustainably. We estimated the prevalence of lemur and fossa meat consumption in villages within and around Makira Natural Park using an indirect questioning method, the unmatched count technique (UCT), and compared it with results from direct questioning. The UCT revealed that 53.0% of households had eaten lemur meat over the previous year (95% confidence interval [CI]: 42.0–64.1%) and 24.2% had eaten fossa meat (95% CI: 14.2–34.2%). The percentage of households that ate lemur meat estimated through the UCT was more than 3.3 times higher than that obtained from direct questioning, and 12 times higher for fossa. Our estimates will be used to define the scale needed for a behavior change campaign to be conducted in the study area and will serve as a baseline to assess the impact of conservation activities aimed at reducing the consumption of lemurs and fossas.

Network optimality has been described in genes, proteins and human communicative networks. In the latter, optimality leads to the efficient transmission of information with a minimum number of connections. Whilst studies show that differences in centrality exist in animal networks with central individuals having higher fitness, network efficiency has never been studied in animal groups. Here we studied 78 groups of primates (24 species). We found that group size and neocortex ratio were correlated with network efficiency. Centralisation (whether several individuals are central in the group) and modularity (how a group is clustered) had opposing effects on network efficiency, showing that tolerant species have more efficient networks. Such network properties affecting individual fitness could be shaped by natural selection. Our results are in accordance with the social brain and cultural intelligence hypotheses, which suggest that the importance of network efficiency and information flow through social learning relates to cognitive abilities.

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]

Wild aye-ayes (Daubentonia madagascariensis) are notoriously difficult to study due to their solitary and nocturnal nature. While research is starting to elucidate the behaviors of wild adult aye-aye, an understanding of behaviors in young aye-ayes is still lacking. We studied the behavioral development of two male aye-aye subadults in Kianjavato, Madagascar from June 2015 to October 2017 and October 2017 to December 2019, and two male offspring in Torotorofotsy, Madagascar, from August 2016 to December 2017 and September 2018 to May 2020. We then compared this information to previous studies on captive infant development. Wild infant aye-ayes first emerged from the nest between two and three months old. Traveling between trees occurred between four and four and a half months old. First attempts at foraging for invertebrates in a woody substrate occurred between five and eight months. Though nursing was rarely observed, the event was witnessed as late as 17 months for one aye-aye. The earliest solo nesting occurred at 18 and a half months of age, and the latest at 23 months old. As with other primates, wild aye-ayes develop more slowly than their captive counterparts. We conclude that their protracted life history is likely associated with their percussive foraging behaviors and importance of invertebrates in their diet. [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]

A red ruffed lemur (Varecia rubra) from a zoo in Louisiana, USA, was euthanized for worsening paresis. Brain and spinal cord histology identified eosinophilic meningoencephalomyelitis with intralesional adult Angiostrongylus sp. nematodes. PCR and sequencing confirmed A. cantonensis infection, indicating this parasite constitutes an emerging zoonosis in the southeastern United States. [ABSTRACT FROM AUTHOR]