An integrated passive acoustic monitoring and deep learning pipeline for black-and-white ruffed lemurs (Varecia variegata) in Ranomafana National Park, Madagascar

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.

Urinary C-peptide and total triiodothyronine as energetic biomarkers for studies of lemurs

Measuring energy balance and energy metabolism can provide crucial information for understanding the ecological and behavioral drivers of an animal's energetic and physiological condition. Both urinary C-peptide (uCP) of insulin and urinary total triiodothyronine (uTT3) have been validated as noninvasive biomarkers of energy balance and metabolic activity in haplorrhine primates. This study attempts to validate uCP and uTT3 measures in strepsirrhines, a phylogenetically distinct primate clade, using the ruffed lemur (genus Varecia) as a model. We experimentally manipulated the diet of captive black-and-white (Varecia variegata) and red (Varecia rubra) ruffed lemurs at Duke Lemur Center across a 4-week period. We collected urine samples from subjects (n = 5) each day during 1 week of control diet, 2 weeks of calorie-restricted diet and 1 week of refeeding, designed to temporarily reduce energy balance and metabolism. We also tested the outcome of filter paper as a storage method by comparing to controls (frozen at -20°C) to assess its suitability for studies of wild populations. We successfully measured uCP and uTT3 levels in frozen urine samples using commercial enzyme immunoassay kits and found that both biomarkers were excreted at lower concentrations (C-peptide: 1.35 ng/mL, 54% reduction; TT3: 1.5 ng/mL, 37.5% reduction) during calorie-restricted periods compared to normal diet periods. Filter paper recovery for uCP was 19%, though values were significantly positively correlated with frozen control samples. uTT3 could not be recovered at measurable concentrations using filter paper. These methods enable noninvasive measurement of energetic conditions in wild strepsirrhines and subsequent assessment of relationships between energy balance and numerous socioecological drivers in primate populations.

Bioacoustic characterization of the black-and-white ruffed lemur (Varecia variegata) vocal repertoire

Ruffed lemurs (Varecia spp.) exhibit a unique suite of behavioral traits compared to other lemur species, which includes their fluid fission-fusion social dynamics, communal rearing of parked litters, and pronounced frugivory in their humid rainforest habitats. Given these traits, and the dense rainforests they inhabit, vocal communication may be key to maintaining social cohesion, coordinating infant care, and/or defending their high-quality food resources. Indeed, they are known for their raucous 'roar-shriek' calls. However, there has been surprisingly little research on vocal communication in Varecia species and only two previously published repertoires, both of which were qualitative descriptions of their calls. In this study, we quantitatively examined the vocal repertoire of wild black-and-white ruffed lemurs (Varecia variegata) at Mangevo, Ranomafana National Park, Madagascar. We characterized 11 call types using 33 bioacoustic parameters related to frequency, duration, tonality, and composition. We also used discriminant function analysis and hierarchical clustering to quantitatively and objectively classify call types within the black-and-white ruffed lemur vocal repertoire. The repertoire consists of both monosyllabic and multisyllabic calls that are individually given or emitted in contagious choruses. Eight of the 11 calls were also used in combination or in larger multi-call sequences. The discriminant function analysis correctly assigned call types with 87% success, though this varied greatly by call type (1-65%). Hierarchical clustering identified 3-4 robust clusters, indicating low clustering structure in the data and suggesting that V. variegata exhibits a graded vocal repertoire. Future work should consider the environmental and behavioral contexts in which calls are used to better understand the function of these call types and combinations.

Functional relationships between estradiol and paternal care in male red-bellied lemurs, Eulemur rubriventer

Fathers contribute substantially to infant care, yet the mechanisms facilitating paternal bonding and interactions with infants are not as well understood as they are in mothers. Several hormonal changes occur as males transition into parenthood, first in response to a partner's pregnancy, and next in response to interacting with the newborn. These changes may prepare fathers for parenting and help facilitate and maintain paternal care. Experimental studies with monkeys and rodents suggest that paternal care requires elevated estradiol levels, which increase when a male's partner is pregnant and are higher in fathers than non-fathers, but its role in the expression of paternal behaviors throughout infant development is unknown. To assess estradiol's role in paternal care, we analyzed the relationship between paternal estradiol metabolites and 1) offspring age, and 2) paternal care behavior (holding, carrying, huddling, playing, grooming), in wild, red-bellied lemurs (Eulemur rubriventer). We collected 146 fecal samples and 1597 h of behavioral data on 10 adult males who had newborn infants during the study. Estradiol metabolites increased four-fold in expectant males, and in new fathers they fluctuated and gradually decreased with time. Infant age, not paternal behavior, best predicted hormone levels in new fathers. These results suggest that hormonal changes occur in expectant males with facultative paternal care, but they do not support the hypothesis that estradiol is directly associated with the day-to-day expression of paternal care. Future research should explore estradiol's role in facilitating behaviors, including infant-directed attention and responsiveness, or preparing fathers for infant care generally.

Terrain Ruggedness and Canopy Height Predict Short-Range Dispersal in the Critically Endangered Black-and-White Ruffed Lemur

Dispersal is a fundamental aspect of primates' lives and influences both population and community structuring, as well as species evolution. Primates disperse within an environmental context, where both local and intervening environmental factors affect all phases of dispersal. To date, research has primarily focused on how the intervening landscape influences primate dispersal, with few assessing the effects of local habitat characteristics. Here, we use a landscape genetics approach to examine between- and within-site environmental drivers of short-range black-and-white ruffed lemur (Varecia variegata) dispersal in the Ranomafana region of southeastern Madagascar. We identified the most influential drivers of short-range ruffed lemur dispersal as being between-site terrain ruggedness and canopy height, more so than any within-site habitat characteristic evaluated. Our results suggest that ruffed lemurs disperse through the least rugged terrain that enables them to remain within their preferred tall-canopied forest habitat. Furthermore, we noted a scale-dependent environmental effect when comparing our results to earlier landscape characteristics identified as driving long-range ruffed lemur dispersal. We found that forest structure drives short-range dispersal events, whereas forest presence facilitates long-range dispersal and multigenerational gene flow. Together, our findings highlight the importance of retaining high-quality forests and forest continuity to facilitate dispersal and maintain functional connectivity in ruffed lemurs.

Nutrient balancing in a fruit-specialist primate, the black-and-white ruffed lemur (Varecia variegata)

Animals' foraging behavior and dietary choices are, in part, driven by their ultimate function: to meet nutritional demands. However, depending on their degree of dietary specialization and the availability and distribution of food resources in their environment, species may utilize different nutritional strategies. With shifting plant phenology, increasing unpredictability of fruiting, and declining food quality in response to anthropogenic climate change, existing nutritional constraints may become exacerbated. Such changes are especially concerning for Madagascar's endemic fruit specialists given the nutrient-limitation of the island's landscapes. In this study, we examined the nutritional strategy of one such fruit-specialist primate, the black-and-white ruffed lemur (Varecia variegata), over a 12-month period (January to December 2018) in Ranomafana National Park, Madagascar. We hypothesized that Varecia would balance nonprotein energy (NPE) to protein (AP) at a high ratio similar to other frugivorous primates, and that they would prioritize protein intake given their high degree of frugivory. We found that Varecia balance NPE:AP at a ratio of 11:1, higher than in any other primate studied to date; however, diets shifted such that nutrient balancing varied seasonally (12.6:1 abundant-9.6:1 lean). Varecia meet NRC suggested recommendations of 5-8% of calories from protein, despite having a diet mostly comprising fruits. However, seasonal shifts in NPE intakes result in significant energy shortfalls during fruit-lean seasons. Flowers provide an important source of NPE during these periods, with flower consumption best predicting lipid intake, suggesting this species' ability to shift resource use. Nevertheless, achieving adequate and balanced nutrient intakes may become precarious in the face of increasing unpredictability in plant phenology and other environmental stochasticities resulting from climate change.

The gut microbiome as an indicator of habitat disturbance in a Critically Endangered lemur

BACKGROUND

Habitat disturbance affects the biology and health of animals globally. Understanding the factors that contribute to the differential responses of animals to habitat disturbance is critical for conservation. The gut microbiota represents a potential pathway through which host responses to habitat disturbance might be mediated. However, a lack of quantitative environmental data in many gut microbiome (GM) studies of wild animals limits our ability to pinpoint mechanisms through which habitat disturbance affects the GM. Here, we examine the impact of anthropogenic habitat disturbance on the diet and GM of the Critically Endangered black-and-white ruffed lemur (Varecia variegata editorum). We collected fecal samples and behavioral data from Varecia occupying habitats qualitatively categorized as primary forest, moderately disturbed forest, and heavily disturbed forest.

RESULTS

Varecia diet and GM composition differed substantially across sites. Dietary richness predicted GM richness across sites, and overall GM composition was strongly correlated to diet composition. Additionally, the consumption of three specific food items positively correlated to the relative abundances of five microbial strains and one microbial genus across sites. However, diet did not explain all of the GM variation in our dataset, and differences in the GM were detected that were not correlated with diet, as measured.

CONCLUSIONS

Our data suggest that diet is an important influence on the Varecia GM across habitats and thus could be leveraged in novel conservation efforts in the future. However, other factors such as contact with humans should also be accounted for. Overall, we demonstrate that quantitative data describing host habitats must be paired with GM data to better target the specific mechanisms through which environmental change affects the GM.

Maternal feeding benefits of allomaternal care in black-and-white colobus (Colobus guereza)

Caring for infants involves lactation, protection, provisioning, and carrying-all energetically taxing states for primate mothers. Holding and carrying clinging infants often constrains mothers from moving and traveling, potentially reducing their food and energy intake; however, when separated from its mother an infant is at risk of predation. This separation therefore requires that mothers be vigilant, further deterring them from feeding. Allomaternal care (AMC) is hypothesized to allow mothers to safely detach from their infants to feed, permitting them to increase energy intake, which is particularly needed for lactation. We examined the nutritional benefits of AMC in black-and-white colobus monkeys (Colobus guereza) by estimating energy intake by lactating mothers during AMC versus non-AMC. We studied seven mother-infant dyads in three groups of C. guereza during six months in Kibale National Park, Uganda. Immature group members handled infants more often than adults, and females handled infants more often than males. An infant's distance to its mother and its nearest neighbor's age and sex best predicted the occurrence of AMC. Lactating mothers fed more often, fed and rested for longer durations, and consumed more metabolizable energy during AMC compared to when they were caring for their infants. These results demonstrate that AMC in C. guereza provides mothers with feeding opportunities that increase their energy intake.

Primate landscape genetics: A review and practical guide

Landscape genetics is an emerging field that integrates population genetics, landscape ecology, and spatial statistics to investigate how geographical and environmental features and evolutionary processes such as gene flow, genetic drift, and selection structure genetic variation at both the population and individual levels, with implications for ecology, evolution, and conservation biology. Despite being particularly well suited for primatologists, this method is currently underutilized. Here, we synthesize the current state of research on landscape genetics in primates. We begin by outlining how landscape genetics has been used to disentangle the drivers of diversity, followed by a review of how landscape genetic methods have been applied to primates. This is followed by a section highlighting special considerations when applying the methods to primates, and a practical guide to facilitate further landscape genetics studies using both existing and de novo datasets. We conclude by exploring future avenues of inquiry that could be facilitated by recent developments as well as underdeveloped applications of landscape genetics to primates.

Fermented food consumption in wild nonhuman primates and its ecological drivers

OBJECTIVES

Although fermented food use is ubiquitous in humans, the ecological and evolutionary factors contributing to its emergence are unclear. Here we investigated the ecological contexts surrounding the consumption of fruits in the late stages of fermentation by wild primates to provide insight into its adaptive function. We hypothesized that climate, socioecological traits, and habitat patch size would influence the occurrence of this behavior due to effects on the environmental prevalence of late-stage fermented foods, the ability of primates to detect them, and potential nutritional benefits.

MATERIALS AND METHODS

We compiled data from field studies lasting at least 9 months to describe the contexts in which primates were observed consuming fruits in the late stages of fermentation. Using generalized linear mixed-effects models, we assessed the effects of 18 predictor variables on the occurrence of fermented food use in primates.

RESULTS

Late-stage fermented foods were consumed by a wide taxonomic breadth of primates. However, they generally made up 0.01%-3% of the annual diet and were limited to a subset of fruit species, many of which are reported to have mechanical and chemical defenses against herbivores when not fermented. Additionally, late-stage fermented food consumption was best predicted by climate and habitat patch size. It was more likely to occur in larger habitat patches with lower annual mean rainfall and higher annual mean maximum temperatures.

DISCUSSION

We posit that primates capitalize on the natural fermentation of some fruits as part of a nutritional strategy to maximize periods of fruit exploitation and/or access a wider range of plant species. We speculate that these factors contributed to the evolutionary emergence of the human propensity for fermented foods.

Seasonal variability in the diet and feeding ecology of black-and-white ruffed lemurs (Varecia variegata) in Ranomafana National Park, southeastern Madagascar

OBJECTIVES

We characterized the diet and foraging ecology of the black-and-white ruffed lemur (Varecia variegata), a specialized frugivore, and investigated behavioral strategies exhibited in response to seasonal changes in resource availability.

MATERIALS AND METHODS

Behavioral data were collected from the same two adjacent communities across 29 months during two observation periods (2007-2008; 2017-2018) in Mangevo, a primary rainforest habitat in southeastern Madagascar. To analyze feeding in the context of energy maximization versus time minimization strategies, we used nonparametric tests to compare plant part constituents, dietary diversity, activity budgets, and canopy strata use between fruit-abundant versus fruit-lean seasons.

RESULTS

Individuals dedicated ~30% of their time to feeding year-round, mostly in the middle canopy (11-20 m). Animals fed primarily on fruits (74% of diet), but frugivory decreased and folivory increased markedly during fruit-lean seasons. Abundant season dietary diversity (98 taxa, H' = 0.71-1.37) was greater than lean season diversity (70 taxa, H' = 0.56-1.06), which coincided with less traveling, more resting, and higher canopy use-though interannual variation was observed.

CONCLUSIONS

Herein, we describe behavioral and dietary patterns that are concordant with a time minimizing behavioral strategy. Black-and-white ruffed lemur diets comprised lower taxonomic diversity, fewer fruits, and more leaves during fruit-lean months. Further, shifts toward less travel, more resting, and greater use of higher canopy levels during this time were most likely for thermoregulatory benefits.

Sex-Segregated Range Use by Black-and-White Ruffed Lemurs (Varecia variegata) in Ranomafana National Park, Madagascar

Ranging behavior is one important strategy by which nonhuman primates obtain access to resources critical to their biological maintenance and reproductive success. As most primates live in permanent social groups, their members must balance the benefits of group living with the costs of intragroup competition for resources. However, some taxa live in more spatiotemporally flexible social groups, whose members modify patterns of association and range use as a method to mitigate these costs. Here, we describe the range use of one such taxon, the black-and-white ruffed lemur (Varecia variegata), at an undisturbed primary rain forest site in Ranomafana National Park, Madagascar, and characterize sex differences in annual home range area, overlap, and daily distances traveled. Moreover, we characterize seasonal variability in range use and ask whether ranging behaviors can be explained by either climatic or reproductive seasonality. We found that females used significantly larger home ranges than males, though sexes shared equal and moderate levels of home range overlap. Overall, range use did not vary across seasons, although within sexes, male range use varied significantly with climate. Moreover, daily path length was best predicted by day length, female reproductive state, and sex, but was unrelated to climate variables. While the patterns of range use and spatial association presented here share some similarities with "bisexually bonded" community models described for chimpanzees, we argue that ruffed lemurs best conform to a "nuclear neighborhood" community model wherein nuclear (core) groups share the highest levels of home range overlap, and where these groups cluster spatially into adjacent "neighborhoods" within the larger, communally defended territory.

Genetic population structure of endangered ring-tailed lemurs (Lemur catta) from nine sites in southern Madagascar

Madagascar's ring-tailed lemurs (Lemur catta) are experiencing rapid population declines due to ongoing habitat loss and fragmentation, as well as increasing exploitation for bushmeat and the illegal pet trade. Despite being the focus of extensive and ongoing behavioral studies, there is comparatively little known about the genetic population structuring of the species. Here, we present the most comprehensive population genetic analysis of ring-tailed lemurs to date from across their likely remaining geographic range. We assessed levels of genetic diversity and population genetic structure using multilocus genotypes for 106 adult individuals from nine geographically representative localities. Population structure and F ST analyses revealed moderate genetic differentiation with localities being geographically partitioned into northern, southern, western and also potentially central clusters. Overall genetic diversity, in terms of allelic richness and observed heterozygosity, was high in the species (AR = 4.74, H O = 0.811). In fact, it is the highest among all published lemur estimates to date. While these results are encouraging, ring-tailed lemurs are currently affected by ongoing habitat fragmentation and occur at lower densities in poorer quality habitats. The effects of continued isolation and fragmentation, coupled with climate-driven environmental instability, will therefore likely impede the long-term viability of the species.

Anthropogenic pressures drive population genetic structuring across a Critically Endangered lemur species range

In recent decades Madagascar has experienced significant habitat loss and modification, with minimal understanding of how human land use practices have impacted the evolution of its flora and fauna. In light of ongoing and intensifying anthropogenic pressures, we seek new insight into mechanisms driving genetic variability on this island, using a Critically Endangered lemur species, the black-and-white ruffed lemur (Varecia variegata), as a test case. Here, we examine the relative influence of natural and anthropogenic landscape features that we predict will impose barriers to dispersal and promote genetic structuring across the species range. Using circuit theory, we model functional connectivity among 18 sampling localities using population-based genetic distance (FST). We optimized resistance surfaces using genetic algorithms and assessed their performance using maximum-likelihood population-effects mixed models. The best supported resistance model was a composite surface that included two anthropogenic features, habitat cover and distance to villages, suggesting that rapid land cover modification by humans has driven change in the genetic structure of wild lemurs. Primary conservation priority should be placed on mitigating further forest loss and connecting regions identified as having low dispersal potential to prevent further loss of genetic diversity and promote the survival of other moist forest specialists.

A description of nesting behaviors, including factors impacting nest site selection, in black-and-white ruffed lemurs (Varecia variegata)

Nest site selection is at once fundamental to reproduction and a poorly understood component of many organisms' reproductive investment. This study investigates the nesting behaviors of black-and-white ruffed lemurs, Varecia variegata, a litter-bearing primate from the southeastern rainforests of Madagascar. Using a combination of behavioral, geospatial, and demographic data, I test the hypotheses that environmental and social cues influence nest site selection and that these decisions ultimately impact maternal reproductive success. Gestating females built multiple large nests throughout their territories. Of these, females used only a fraction of the originally constructed nests, as well as several parking locations as infants aged. Nest construction was best predicted by environmental cues, including the size of the nesting tree and density of feeding trees within a 75 m radius of the nest, whereas nest use depended largely on the size and average distance to feeding trees within that same area. Microhabitat characteristics were unrelated to whether females built or used nests. Although unrelated to nest site selection, social cues, specifically the average distance to conspecifics' nest and park sites, were related to maternal reproductive success; mothers whose litters were parked in closer proximity to others' nests experienced higher infant survival than those whose nests were more isolated. This is likely because nesting proximity facilitated communal crèche use by neighboring females. Together, these results suggest a complex pattern of nesting behaviors that involves females strategically building nests in areas with high potential resource abundance, using nests in areas according to their realized productivity, and communally rearing infants within a network of nests distributed throughout the larger communal territory.

Novel opsin gene variation in large-bodied, diurnal lemurs

Some primate populations include both trichromatic and dichromatic (red-green colour blind) individuals due to allelic variation at the X-linked opsin locus. This polymorphic trichromacy is well described in day-active New World monkeys. Less is known about colour vision in Malagasy lemurs, but, unlike New World monkeys, only some day-active lemurs are polymorphic, while others are dichromatic. The evolutionary pressures underlying these differences in lemurs are unknown, but aspects of species ecology, including variation in activity pattern, are hypothesized to play a role. Limited data on X-linked opsin variation in lemurs make such hypotheses difficult to evaluate. We provide the first detailed examination of X-linked opsin variation across a lemur clade (Indriidae). We sequenced the X-linked opsin in the most strictly diurnal and largest extant lemur, Indri indri, and nine species of smaller, generally diurnal indriids (Propithecus). Although nocturnal Avahi (sister taxon to Propithecus) lacks a polymorphism, at least eight species of diurnal indriids have two or more X-linked opsin alleles. Four rainforest-living taxa-I. indri and the three largest Propithecus species-have alleles not previously documented in lemurs. Moreover, we identified at least three opsin alleles in Indri with peak spectral sensitivities similar to some New World monkeys.

Social behaviour and gut microbiota in red-bellied lemurs (Eulemur rubriventer): In search of the role of immunity in the evolution of sociality

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

The Paucity of Frugivores in Madagascar May Not Be Due to Unpredictable Temperatures or Fruit Resources

The evolution of ecological idiosyncrasies in Madagascar has often been attributed to selective pressures stemming from extreme unpredictability in climate and resource availability compared to other tropical areas. With the exception of rainfall, few studies have investigated these assumptions. To assess the hypothesis that Madagascar's paucity of frugivores is due to unreliability in fruiting resources, we use statistical modeling to analyze phenology datasets and their environmental correlates from two tropical wet forests, the Réserve Naturelle Intégrale Betampona in Madagascar, and Kibale National Park in Uganda. At each site we found that temperature is a good environmental predictor of fruit availability. We found no evidence of a significant difference in the predictability of fruit availability between the two sites, although the shorter duration of phenological monitoring at Betampona (two years, versus 15 years at Kibale) limits our ability to infer long-term patterns. Comparisons of long-term temperature data from each site (15 years from Kibale and 14 from Betampona) indicate that temperature is more predictable at Betampona than at Kibale. However, there does appear to be a difference between the two sites in the total fruit availability at any given time, with fruit being generally less abundant at Betampona. Our results appear contrary to the prevailing hypothesis of a selective force imposed by unpredictable resource availability or temperature, and we suggest other possible explanations for Madagascar's unique biota.

Species-level view of population structure and gene flow for a critically endangered primate (Varecia variegata)

Lemurs are among the world's most threatened mammals. The critically endangered black-and-white ruffed lemur (Varecia variegata), in particular, has recently experienced rapid population declines due to habitat loss, ecological sensitivities to habitat degradation, and extensive human hunting pressure. Despite this, a recent study indicates that ruffed lemurs retain among the highest levels of genetic diversity for primates. Identifying how this diversity is apportioned and whether gene flow is maintained among remnant populations will help to diagnose and target conservation priorities. We sampled 209 individuals from 19 sites throughout the remaining V. variegata range. We used 10 polymorphic microsatellite loci and ∼550 bp of mtDNA sequence data to evaluate genetic structure and population dynamics, including dispersal patterns and recent population declines. Bayesian cluster analyses identified two distinct genetic clusters, which optimally partitioned data into populations occurring on either side of the Mangoro River. Localities north of the Mangoro were characterized by greater genetic diversity, greater gene flow (lower genetic differentiation) and higher mtDNA haplotype and nucleotide diversity than those in the south. Despite this, genetic differentiation across all sites was high, as indicated by high average F ST (0.247) and ΦST (0.544), and followed a pattern of isolation-by-distance. We use these results to suggest future conservation strategies that include an effort to maintain genetic diversity in the north and restore connectivity in the south. We also note the discordance between patterns of genetic differentiation and current subspecies taxonomy, and encourage a re-evaluation of conservation management units moving forward.

Morphometrics of wild black-and-white ruffed lemurs [Varecia variegata; Kerr, 1792]

This study presents the first detailed morphometric measurements of wild caught black-and-white ruffed lemurs (Varecia variegata) from the eastern rainforests of Madagascar and aims to quantify the morphological variation present throughout their recognized range. One hundred and forty-four adult and juvenile individuals from 15 sites were sampled for 20 cranial, dental and postcranial morphometric and body mass measurements. Data were collected from an equal number of male and female individuals sampled across seasons over a 7-year period (1999-2002, 2004-2006). Results indicate that adult body mass and morphometric measurements varied between sexes across sites; however, the only significant intersexual difference found was that females possessed, on average, longer tails than males. Contrary to previous studies, significant seasonal variation could not be detected in either male or female body mass or testicular volume (i.e., breeding vs. nonbreeding, food-scarce vs. food-abundant seasons). Measurements did, however, vary significantly by site and subspecies, though clinal variation could not explain these differences. The introduced population from Nosy Mangabe exhibited significantly lower body mass and overall body length than all other populations; however, this distinction may not have been attributable to natural variation, and may have instead resulted from the ecologically restrictive habitat (e.g., unusually high lemur population densities, limited food resources, ecological isolation) of this introduced population. Finally, although fore-to-hindlimb, brachium-to-thigh and hindlimb indices were comparable to previous values, forelimb indices calculated here deviate significantly from previous reports, placing V. variegata within the upper range of lemurid taxa. It is currently unknown whether this is an artifact of sampling methods (i.e., live vs. skeletal specimens) or whether this is an avenue that warrants further investigation.

An approach to assessing the reliability of anthropometrics in elderly patients

Although anthropometrics have traditionally been utilized in the assessment of protein-energy malnutrition, little is known of the reliability of these measurements in elderly patient populations. In this study, the reliability of an anthropometric measurement protocol, designed for ease in measurement of both independent and functionally debilitated elderly patients, is evaluated. An analysis of variance technique was used to calculate the test-retest variance for each of three observers. Although the experience of the three observers was equivalent, the precision of their measurements varied considerably. After repeat practice sessions, improved measurement reliability was demonstrated. For all the observers, the test-retest variance was found to be proportional to the size of the measurement and to be influenced by the accuracy in which the site for each measurement was located. Based on this study, we conclude that when using anthropometrics it is important to know the reliability of each observers' measurements. Because of the correlation between the test-retest variance and the measurement value, we suggest that the variance be expressed as a percentile. A method for transforming the variances is presented.