Consistency in Verreaux's sifaka home range and core area size despite seasonal variation in resource availability as assessed by Enhanced Vegetation Index (EVI).

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.

The role of developmental rate, body size, and positional behavior in the evolution of covariation and evolvability in the cranium of strepsirrhines and catarrhines.

Recent studies on hominin craniofacial evolution have focused on phenotypic integration or covariation among traits. Covariation is thought to significantly affect evolutionary trajectories, shaping the ways in which hominins and other primates could have evolved. However, the ways in which covariation itself evolves are not well understood. This study aims to investigate the role of phylogeny, development, body size, and positional behavior in shaping the strength of covariation in strepsirrhine and catarrhine primate crania (n = 1009, representing 11 genera). These factors may have been catalysts for change in the magnitude of covariation, and they have changed significantly during primate evolution and particularly hominin evolution. Modern humans in particular have slow developmental trajectories, large bodies, and a unique form of locomotion in the form of orthograde bipedalism. Variance of eigenvalues, mean integration, mean evolvability, and mean conditional evolvability was estimated and their relationship to the various factors described earlier was assessed using phylogenetic and nonphylogenetic analyses. Results indicate that some phylogenetic signal is present, but it is not equivalent across integration statistics or cranial regions. In particular, these results suggest that closely related species are more similar than more distantly related species in evolvability of the cranial base and integration of the face. Two divergent patterns were also identified, in which covariation and evolvability of the cranial base are linked to developmental rate, but those of the face are linked to body size. Neither locomotion nor posture appears related to covariation or evolvability of the primate cranium. These results suggest that overall low covariation observed in the hominin cranium may be a result of separate trends in different cranial regions.

The Influence of Seasonal Availability of Young Leaves on Dietary Niche Separation in Two Ecologically Similar Folivorous Lemurs.

Traditional socio-ecological models consider that folivorous primates experience limited feeding competition due to the low quality, high abundance, and even distribution of leaves. Evidence from several folivorous species that experience similar constraints to frugivores does not support this hypothesis. The sympatric lemur genera Avahi (Indriidae) and Lepilemur (Lepilemuridae) are good models to understand how food availability constrains folivores since they are both nocturnal, folivorous, and have a comparable body mass. Here we investigate how two nocturnal folivorous primates, Avahi meridionalis and Lepilemur fleuretae, living in the lowland rain forest of Tsitongambarika, South-East Madagascar, partition their dietary niche and are influenced by seasonality of young leaves. To account for food availability, we collected annual phenological data on 769 trees from 200 species. We also collected behavioural data on 5 individuals per lemur species from August 2015 to July 2016 via continuous focal sampling. We found the phenological profile to be seasonal with peaks of leaf flushing, flowering, and fruiting occurring in the austral summer. The two species showed limited dietary overlap (37% rich period, 6% lean period), and A. meridionalis showed higher feeding time and longer daily distances travelled during the rich period. Lepilemur fleuretae showed a dietary shift during the lean period, relying more on mature leaves (73.3% during the lean period, 13.5% during the rich period) but maintaining similar activity levels between seasons. The time spent feeding on food items by A. meridionalis was positively correlated with the nitrogen content and negatively correlated with polyphenols during the rich period. We highlighted a clear effect of the seasonality of young leaves on the diet, nutritional content, activity patterns, and daily distances travelled by two folivorous species, which can be linked to nutrient balancing and time-minimising versus energy-maximising strategies.

First navicular remains of a European adapiform (Anchomomys frontanyensis) from the Middle Eocene of the Eastern Pyrenees (Catalonia, Spain): implications for early primate locomotor behavior and navicular evolution.

We describe the first known navicular bones for an Eocene euprimate from Europe and assess their implications for early patterns of locomotor evolution in primates. Recovered from the fossil site of Sant Jaume de Frontanyà-3C (Barcelona, Spain), the naviculars are attributed to Anchomomys frontanyensis. The small size of A. frontanyensis allows us to consider behavioral implications of comparisons with omomyiforms, regardless of allometric sources of navicular variation. Researchers usually consider omomyiforms to be more prone to leaping than contemporaneous adapiforms partly because of the more pronounced elongation of omomyiform tarsal elements. However, A. frontanyensis differs from other adapiforms and is similar to some omomyiforms in its more elongated navicular proportions. Although this might raise questions about attribution of these naviculars to A. frontanyensis, the elements exhibit clear strepsirrhine affinities leaving little doubt about the attribution: the bones' mesocuneiform facets contact their cuboid facets. We further propose that this strepsirrhine-specific feature in A. frontanyensis and other adapiforms reflects use of more inverted foot postures and potentially smaller substrates than sympatric omomyiforms that lack it. Thus substrate differences may have influenced niche partitioning in Eocene euprimate communities along with differences in locomotor agility. As previous studies on the astragalus and the calcaneus have suggested, this study on the navicular is consistent with the hypothesis that the locomotor mode of A. frontanyensis was similar to that of extant cheirogaleids, especially species of Microcebus and Mirza.

Re-assessing the applicability of the Jarman/Bell model and Kay's threshold to the insectivorous aye-aye (Daubentonia madagascariensis).

OBJECTIVES: Jarman/Bell principle and Kay's threshold suggest that large animals should not be able to sustain themselves on insects. However, animals with specialized morphological and/or behavioral adaptations violate these assumptions. Male aye-ayes were recently identified as having an insectivorous diet despite weighing 2.5 kg. We further explored this diet/body size disparity by studying behaviors of an adult female and juvenile male aye-aye. MATERIALS AND METHODS: We collected behavioral data on an adult female and juvenile male aye-aye in Torotorofotsy, Madagascar from January 2016 to December 2017. We used instantaneous sampling to determine the frequency of feeding events and continuous sampling during feeding behaviors to assess duration of feeding bouts. RESULTS: Invertebrates comprised over 88% of the diet for both animals. A Wilcoxon signed-rank test found no significant difference in the female's feeding frequencies between the hot/rainy seasons and the cold/dry seasons. DISCUSSION: Our results support earlier findings that invertebrates are the aye-aye's main resource and corroborate that aye-ayes violate assumptions of the Jarman/Bell model and Kay's threshold. We suggest that the Jarman/Bell principle and Kay's threshold be used as supporting evidence and not to repudiate findings that do not conform to these guidelines.

Female Power: A New Framework for Understanding "Female Dominance" in Lemurs.

Female dominance is often associated with lemurs. However, consensus does not exist among primatologists on how to define, measure, or explain female dominance. This review explores the utility of applying a broader concept of power to understanding lemur intersexual relationships. In this framework, power is defined as arising from an asymmetry in a dyadic relationship and can be divided into 2 types: dominance and leverage. Intersexual asymmetries based upon females having superior fighting ability are considered female dominance. However, economic power also exists, and females with resource-based power exhibit female leverage. Additionally, power has 4 characteristics (base, means, amount, and scope) that describe the precise nature of observed phenomena. This article utilizes the 4 characteristics outlined in the power framework to review the existing "female dominance" literature for lemurs and highlights the value of adopting both an expanded concept of power and a more precise language. By placing the multiple phenomena currently labeled under the single term "female dominance" within the power framework, much of the confusion disappears. Thus, not only is the debate reframed, facilitating endeavors to find evolutionary explanations, but the uniqueness of female power in lemurs can be determined empirically rather than by definition.

Systematic and locomotor diversification of the Adapis group (Primates, Adapiformes) in the late Eocene of the Quercy (Southwest France), revealed by humeral remains.

Twenty humeral specimens from the old and new Quercy collections attributed to the fossil primates Adapis and Palaeolemur are described and analysed together. We provide a qualitative and quantitative analysis of the different humeri, revealing that high variability is present within the "Adapis group" sample. Six different morphotypes are identified, confirming that what has often been called "Adapis parisiensis" is a mix of different species that present different locomotor adaptations. Such a relatively high level of locomotor diversity is unique in the Paleogene primate fossil record. The humeral proportions of Adapis overlap with different groups of extant strepsirrhines and platyrrhines depending on the specimen, so the popular view of Adapis as a loris-like slow climbing primate does not apply to the whole sample presented here. Moreover, different humeral features traditionally associated with "Adapis parisiensis", such as the absence of a zona conoidea and a reduced brachioradialis flange, are variable depending on the sample studied. In addition, results of our analyses show that adapine and omomyid humeral morphology overlap extensively, leading us to question the accuracy of taxonomic attributions based on morphology of isolated humeri at localities where omomyids and adapines of similar size coexist. Finally, assuming our different morphotypes represent different species within two genera, we propose a phylogenetic hypothesis relating these morphotypes, which inhabited a small geographic area.

Middle ear pneumatization in nonhuman primates: A comparative analysis.

OBJECTIVES: We test the effects of body mass and phylogeny on middle ear cavity pneumatization, and the role of pneumatization in hearing function, spanning the anatomical, ecological, and behavioral diversity of nonhuman primates. MATERIALS AND METHODS: All cavities were segmented in middle ear scans of 96 specimens, from 12 strepsirrhine and 15 haplorhine extant species. We measured the tympanic cavity (TC) separately, and all other middle ear spaces together (MES), calculating the degree of pneumatization with the surface area-to-volume ratio. We tested body mass effect with linear regression; we evaluated the phylogenetic signal and selection patterns, using a Kappa statistic test, and Ornstein-Uhlenbeck models (OU). We investigated the link between pneumatization and hearing sensitivity using phylogenetic regression. RESULTS: Testing body mass reveals an allometric pattern for both TC and MES dimensions. Degree of pneumatization in MES is dependent on body mass in haplorhines: larger animals have more pneumatized MES. Differences at various taxonomic ranks were observed for MES, while no phylogenetic influence was observed for TC. Infraorder selection patterns are different. Auditory performance is significantly related to degree of pneumatization, indicating that a pneumatized middle ear is associated with better perception of low frequencies. DISCUSSION: Pneumatization in MES is under differential selective pressure, indicating several optima for this trait. Pneumatization in MES probably modifies hearing sensitivity through pressure regulation mechanisms, auditory bulla size reduction, and frequency modulation. This could explain strepsirrhine adaptation to high-frequency perception, while haplorhine auditory perception is adapted to a broader sound range, including high and low frequencies.

Spatiotemporal distribution of individuals as an indicator for the social system of Lepilemur sahamalaza.

Primate social systems are highly diverse, complicating the classification of particularly elusive species that are difficult to observe. The spatial distribution of individuals over time is a critica lindicator for the social organization and long-term studies are important to establish patterns of social interactions. In recent years, species of the cryptic, nocturnal sportive lemurs of the genus Lepilemur were found to live in pairs in which a single male and a single female share and defend a mutual home range. The present study aimed to forward research into this underrepresented genus by determining the social organization and structure of the Sahamalaza sportive lemur, L. sahamalaza. We collected 773.15 hr of behavioral and GPS data during a period of 10 months (between 2015 and 2016) on 14 individuals: eight females and six males. There was no evidence of pair-specific home range use as intra- and intersexual home range overlap was high. No pattern of social interactions between focal individuals could be distinguished despite high range overlap. Individuals met and interacted infrequently, resulting in an interaction rate of 0.32 interactions/hr. Sleeping associations between adult individuals were never observed. While both sexes had access to multiple potential mating partners, range sizes or ranging distances did not increase in mating periods. Overall, the social system of Sahamalaza sportive lemurs exhibits aspects of a solitary social organization and structure with potential for the polygamous mating system. These findings underline the importance of detailed social ecology studies that can provide the basis for understanding potential environmental influences on social system variability of closely related species.

A comparative study of gut microbiomes in captive nocturnal strepsirrhines.

Feeding strategy and diet are increasingly recognized for their roles in governing primate gut microbiome (GMB) composition. Whereas feeding strategy reflects evolutionary adaptations to a host's environment, diet is a more proximate measure of food intake. Host phylogeny, which is intertwined with feeding strategy, is an additional, and often confounding factor that shapes GMBs across host lineages. Nocturnal strepsirrhines are an intriguing and underutilized group in which to examine the links between these three factors and GMB composition. Here, we compare GMB composition in four species of captive, nocturnal strepsirrhines with varying feeding strategies and phylogenetic relationships, but nearly identical diets. We use 16S rRNA sequences to determine gut bacterial composition. Despite similar husbandry conditions, including diet, we find that GMB composition varies significantly across host species and is linked to host feeding strategy and phylogeny. The GMBs of the omnivorous and the frugivorous species were significantly more diverse than were those of the insectivorous and exudativorous species. Across all hosts, GMBs were enriched for bacterial taxa associated with the macronutrient resources linked to the host's respective feeding strategy. Ultimately, the reported variation in microbiome composition suggests that the impacts of captivity and concurrent diet do not overshadow patterns of feeding strategy and phylogeny. As our understanding of primate GMBs progresses, populations of captive primates can provide insight into the evolution of host-microbe relationships, as well as inform future captive management protocols that enhance primate health and conservation.

Implications of lemuriform extinctions for the Malagasy flora.

Madagascar's lemurs display a diverse array of feeding strategies with complex relationships to seed dispersal mechanisms in Malagasy plants. Although these relationships have been explored previously on a case-by-case basis, we present here the first comprehensive analysis of lemuriform feeding, to our knowledge, and its hypothesized effects on seed dispersal and the long-term survival of Malagasy plant lineages. We used a molecular phylogenetic framework to examine the mode and tempo of diet evolution, and to quantify the associated morphological space occupied by Madagascar's lemurs, both extinct and extant. Using statistical models and morphometric analyses, we demonstrate that the extinction of large-bodied lemurs resulted in a significant reduction in functional morphological space associated with seed dispersal ability. These reductions carry potentially far-reaching consequences for Malagasy ecosystems, and we highlight large-seeded Malagasy plants that appear to be without extant animal dispersers. We also identify living lemurs that are endangered yet occupy unique and essential dispersal niches defined by our morphometric analyses.

Sahamalaza Sportive Lemur, Lepilemur sahamalaza, Vocal Communication: Call Use, Context and Gradation.

Stereotypical vocalisations can facilitate long-distance communication in dense and, thus, sound-degrading forest habitats. Despite this, primate vocal repertoires often also include gradations between different call types that are used in social interactions. Because many nocturnal primates show a solitary social structure, it has been difficult to assess the role vocalisations play in mediating their social encounters. Here we aim to expand on the call types of Sahamalaza sportive lemurs, Lepilemur sahamalaza, as well as investigate their variability and use in social contexts. Through long-term behavioural observations with concurrent recording of vocalisations of known and unknown individuals between 2015 and 2016, we described three previously unrecorded calls and expanded the vocal repertoire to 12 different call types that were used in both targeted social and broadcast solitary contexts. Linear discriminant function and cluster analysis supported initial observations that vocalisations within call types were variable and that at least two call types can be classified as "graded," contrary to expectations. Despite variations in call-context connections, no clear patterns of call use could be established. However, measurable differences in vocal behaviour between the seasons and the sexes indicate that calling is used in a reproductive context, similar to other nocturnal and diurnal primates.

Nocturnal Primate Communication: Ecology, Evolution and Conservation.

Auditory, visual and olfactory cues play varying roles in non-human primate communication, and these systems have been intensively studied over the last several decades. The use of vocalisations as a primary mode of communication has been the focus of much research, especially in attempts to understand the origins of human language, with a major focus on anthropoid primates and diurnal lemurs. Over the last decade, technological advances have allowed researchers to begin to conduct in-depth investigations into the communication systems exhibited by the nocturnal and cathemeral prosimian primates, including tarsiers, lemurs and lorises. Understanding how nocturnal prosimians use visual, olfactory and auditory cues is vital for reconstructing the origins of primate communication systems. In this special issue, we highlight some of the more exciting advances in the communication strategies of the prosimians. Contributions come from work conducted in Kenya, Tanzania, Senegal, Rwanda, Madagascar and the Indonesian islands of Java and Sulawesi. Topics will include: the description of novel ultrasonic vocalisations, including frequency and function of these newly discovered calls; the possible use of vocalisations to navigate and assemble at sleep sites; the importance of species-specific contact vocalisations for the identification of new species; the use of urinary and glandular signals to communicate and the methods developed to understand this complex communication in the field; the use of vocalisations for niche separation among nocturnal primates from mainland Africa and Madagascar; and whether or not we can use new technologies to discern whether prosimians use vocalisations for individual identification of group members. We discuss the importance of new field methods including novel equipment and techniques, the use of vocalisation to influence conservation practices and the importance of comparing across prosimian taxa to reconstruct the communication systems of our early primate ancestors.

P-Mail: The Information Highway of Nocturnal, but Not Diurnal or Cathemeral, Strepsirrhines.

Scent marking is a well-established, but highly variable, mode of communication among strepsirrhine primates. We begin by reviewing this literature, focusing on nocturnal species. Our understanding about the information content of scent signals and the factors driving species diversity remains incomplete, owing to difficulties in acquiring comparative chemical data. We therefore re-examine such a data set, representing the richness and relative abundance of volatile organic compounds (VOCs) in the urine of 12 species (from Galagidae, Lorisidae, Daubentoniidae, Cheirogaleidae, Indriidae, and Lemuridae), to explore differences between nocturnal, diurnal and cathemeral species. As predicted by the variable importance of urine marking across species, the urine of nocturnal strepsirrhines contained the most VOCs and putative semiochemicals, differed significantly in composition from that of diurnal and cathemeral species and showed the strongest species scent "signatures." Relevant to retracing the evolutionary trajectory of cathemeral strepsirrhines, nocturnal and diurnal species were most differentiated in their VOCs, with cathemeral species being intermediary, but more closely aligned with diurnal species. These data support cathemerality as an ancient expansion of diurnal animals into a nocturnal niche. Consideration of the traits and variables associated with olfactory communication offers a profitable new way for examining species diversity and patterns of evolutionary change.

Evaluating the triplet hypothesis during rhythmic mastication in primates.

Mammalian mastication involves precise jaw movements including transverse movement of the mandible during the power stroke. Jaw elevation and transverse movement are driven by asymmetrical jaw elevator muscle activity, which is thought to include a phylogenetically primitive and conserved triplet motor pattern consisting of: triplet I (balancing side: superficial masseter and medial pterygoid; working side: posterior temporalis), which reaches onset, peak and offset first; and triplet II (working side: superficial masseter and medial pterygoid; balancing side: posterior temporalis), which is active second. Although the presence of a triplet motor pattern has been confirmed in several primate species, the prevalence of this motor pattern - i.e. the proportion of masticatory cycles that display it - has not been evaluated in primates. The present study quantifies the presence and prevalence of the triplet motor pattern in five different primate species, Eulemur fulvus, Propithecus verreauxi, Papio anubis, Macacafuscata and Pan troglodytes, using mean onset, peak and offset time relative to working superficial masseter. In all five of the species studied, the mean triplet motor pattern was observed at peak muscle activation, and in four out of the five species the triplet motor pattern occurred more frequently than expected at random at peak muscle activation and offset. Non-triplet motor patterns were observed in varying proportions at different time points in the masticatory cycle, suggesting that the presence or absence of the triplet motor pattern is not a binomial trait. Instead, the primate masticatory motor pattern is malleable within individual cycles, within individual animals and therefore within species.

The inside tract: The appendicular, cecal, and colonic microbiome of captive aye-ayes.

OBJECTIVES: The aye-aye (Daubentonia madagascariensis) is famous for its feeding strategies that target structurally defended, but high-quality resources. Nonetheless, the influence of this digestible diet on gut microbial contributions to aye-aye metabolism and nutrition remains unexplored. When four captive aye-ayes were unexpectedly lost to persin toxicity, we opportunistically collected samples along the animals' gastrointestinal tracts. Here we describe the diversity and composition of appendicular, cecal, and colonic consortia relative to the aye-aye's unusual feeding ecology. MATERIALS AND METHODS: During necropsies, we collected digestive content from the appendix, cecum, and distal colon. We determined microbiome structure at these sites via amplicon sequencing of the 16S rRNA gene and an established bioinformatics pipeline. RESULTS: The aye-ayes' microbiomes exhibited low richness and diversity compared to the consortia of other lemurs housed at the same facility, and were dominated by a single genus, Prevotella. Appendicular microbiomes were differentiated from more homogenized cecal and colonic consortia by lower richness and diversity, greater evenness, and a distinct taxonomic composition. DISCUSSION: The simplicity of the aye-aye's gut microbiome could be attributed to captivity-induced dysbiosis, or it may reflect this species' extreme foraging investment in a digestible diet that requires little microbial metabolism. Site-specific appendicular consortia, but more similar cecal and colonic consortia, support the theory that the appendix functions as a safe-house for beneficial bacteria, and confirm fecal communities as fairly reliable proxies for consortia along the lower gut. We encourage others to make similar use of natural or accidental losses for probing the primate gut microbiome.

Do forelimb shape and peak forces co-vary in strepsirrhines?

OBJECTIVES: In this study, we explore whether ground reaction forces recorded during horizontal walking co-vary with the shape of the long bones of the forelimb in strepsirrhines. To do so, we quantify (1) the shape of the shaft and articular surfaces of each long bone of the forelimb, (2) the peak vertical, mediolateral, and horizontal ground reaction forces applied by the forelimb during arboreal locomotion, and (3) the relationship between the shape of the forelimb and peak forces. MATERIALS AND METHODS: Geometric morphometric approaches were used to quantify the shape of the bones. Kinetic data were collected during horizontal arboreal walking in eight species of strepsirrhines that show variation in habitual substrate use and morphology of the forelimb. These data were then used to explore the links between locomotor behavior, morphology, and mechanics using co-variation analyses in a phylogenetic framework. RESULTS: Our results show significant differences between slow quadrupedal climbers (lorises), vertical clinger and leapers (sifaka), and active arboreal quadrupeds (ring-tailed lemur, ruffed lemur) in both ground reaction forces and the shape of the long bones of the forelimb, with the propulsive and medially directed peak forces having the highest impact on the shape of the humerus. Co-variation between long bone shape and ground reaction forces was detected in both the humerus and ulna even when accounting for differences in body mass. DISCUSSION: These results demonstrate the importance of considering limb-loading beyond just peak vertical force, or substrate reaction force. A re-evaluation of osseous morphology and functional interpretations is necessary in light of these findings.

Subcortical barrelette-like and barreloid-like structures in the prosimian galago (Otolemur garnetti).

Galagos are prosimian primates that resemble ancestral primates more than most other extant primates. As in many other mammals, the facial vibrissae of galagos are distributed across the upper and lower jaws and above the eye. In rats and mice, the mystacial macrovibrissae are represented throughout the ascending trigeminal pathways as arrays of cytoarchitecturally distinct modules, with each module having a nearly one-to-one relationship with a specific facial whisker. The macrovibrissal representations are termed barrelettes in the trigeminal somatosensory brainstem, barreloids in the ventroposterior medial subnucleus of the thalamus, and barrels in primary somatosensory cortex. Despite the presence of facial whiskers in all nonhuman primates, barrel-like structures have not been reported in primates. By staining for cytochrome oxidase, Nissl, and vesicular glutamate transporter proteins, we show a distinct array of barrelette-like and barreloid-like modules in the principal sensory nucleus, the spinal trigeminal nucleus, and the ventroposterior medial subnucleus of the galago, Otolemur garnetti. Labeled terminals of primary sensory neurons in the brainstem and cell bodies of thalamocortically projecting neurons demonstrate that barrelette-like and barreloid-like modules are located in areas of these somatosensory nuclei that are topographically consistent with their role in facial touch. Serendipitously, the plane of section that best displays the barreloid-like modules reveals a remarkably distinct homunculus-like patterning which, we believe, is one of the clearest somatotopic maps of an entire body surface yet found.

Behaviour and Ecology of Male Aye-Ayes (Daubentonia madagascariensis) in the Kianjavato Classified Forest, South-Eastern Madagascar.

Previous studies found that aye-ayes (Daubentonia madagascariensis) consume a variety of non-invertebrate resources, supporting the hypothesis that aye-ayes are too large-bodied to focus feeding efforts on insects. However, these conclusions were based on introduced populations, with little known about aye-aye behaviour and ecology in its natural habitat. This study investigates activity budgets, diet, and home range/territories of 2 male aye-ayes in the Kianjavato Classified Forest, a disturbed forest in south-eastern Madagascar, from October 2013 to October 2014. We used radiotelemetry and focal-animal sampling methods to collect behavioural data. We recorded GPS coordinates of the focal animal every 20 min, calculating the home range size for each individual. Results showed that male aye-ayes spent most of their time feeding and travelling. Their feeding time primarily focussed on larvae and adult insects from various substrates, and to a lesser extent Canarium spp. seeds. Home range sizes of the 2 males varied between individuals, overlapped greatly, and appeared to be related to the location of females. Our findings indicate that aye-aye behaviours are strongly indicative of insect-centric feeding ecology.

Hierarchical social networks shape gut microbial composition in wild Verreaux's sifaka.

In wild primates, social behaviour influences exposure to environmentally acquired and directly transmitted microorganisms. Prior studies indicate that gut microbiota reflect pairwise social interactions among chimpanzee and baboon hosts. Here, we demonstrate that higher-order social network structure-beyond just pairwise interactions-drives gut bacterial composition in wild lemurs, which live in smaller and more cohesive groups than previously studied anthropoid species. Using 16S rRNA gene sequencing and social network analysis of grooming contacts, we estimate the relative impacts of hierarchical (i.e. multilevel) social structure, individual demographic traits, diet, scent-marking, and habitat overlap on bacteria acquisition in a wild population of Verreaux's sifaka (Propithecus verreauxi) consisting of seven social groups. We show that social group membership is clearly reflected in the microbiomes of individual sifaka, and that social groups with denser grooming networks have more homogeneous gut microbial compositions. Within social groups, adults, more gregarious individuals, and individuals that scent-mark frequently harbour the greatest microbial diversity. Thus, the community structure of wild lemurs governs symbiotic relationships by constraining transmission between hosts and partitioning environmental exposure to microorganisms. This social cultivation of mutualistic gut flora may be an evolutionary benefit of tight-knit group living.