Eulemur Macaco Flavifrons Research Articles

Diverse Circular DNA Viral Communities in Blood, Oral, and Fecal Samples of Captive Lemurs.

Few studies have addressed viral diversity in lemurs despite their unique evolutionary history on the island of Madagascar and high risk of extinction. Further, while a large number of studies on animal viromes focus on fecal samples, understanding viral diversity across multiple sample types and seasons can reveal complex viral community structures within and across species. Groups of captive lemurs at the Duke Lemur Center (Durham, NC, USA), a conservation and research center, provide an opportunity to build foundational knowledge on lemur-associated viromes. We sampled individuals from seven lemur species, i.e., collared lemur (Eulemur collaris), crowned lemur (Eulemur coronatus), blue-eyed black lemur (Eulemur flavifrons), ring-tailed lemur (Lemur catta), Coquerel's sifaka (Propithecus coquereli), black-and-white ruffed lemur (Varecia variegata variegata), and red ruffed lemur (Varecia rubra), across two lemur families (Lemuridae, Indriidae). Fecal, blood, and saliva samples were collected from Coquerel's sifaka and black-and-white ruffed lemur individuals across two sampling seasons to diversify virome biogeography and temporal sampling. Using viral metagenomic workflows, the complete genomes of anelloviruses (n = 4), cressdnaviruses (n = 47), caudoviruses (n = 15), inoviruses (n = 34), and microviruses (n = 537) were determined from lemur blood, feces, and saliva. Many virus genomes, especially bacteriophages, identified in this study were present across multiple lemur species. Overall, the work presented here uses a viral metagenomics approach to investigate viral communities inhabiting the blood, oral cavity, and feces of healthy captive lemurs.

Tradeoffs between bite force and gape in Eulemur and Varecia.

In 1974, Sue Herring described the relationship between two important performance variables in the feeding system, bite force and gape. These variables are inversely related, such that, without specific muscular adaptations, most animals cannot produce high bite forces at large gapes for a given sized muscle. Despite the importance of these variables for feeding biomechanics and functional ecology, the paucity of in vivo bite force data in primates has led to bite forces largely being estimated through ex vivo methods. Here, we quantify and compare in vivo bite forces and gapes with output from simulated musculoskeletal models in two craniofacially distinct strepsirrhines: Eulemur, which has a shorter jaw and slower chewing cycle durations relative to jaw length and body mass compared to Varecia. Bite forces were collected across a range of linear gapes from 16 adult lemurs (suborder Strepsirrhini) at the Duke Lemur Center in Durham, North Carolina representing three species: Eulemur flavifrons (n = 6; 3F, 3M), Varecia variegata (n = 5; 3F, 2M), and Varecia rubra (n = 5; 5F). Maximum linear and angular gapes were significantly higher for Varecia compared to Eulemur (p = .01) but there were no significant differences in recorded maximum in vivo bite forces (p = .88). Simulated muscle models using architectural data for these taxa suggest this approach is an accurate method of estimating bite force-gape tradeoffs in addition to variables such as fiber length, fiber operating range, and gapes associated with maximum force. Our in vivo and modeling data suggest Varecia has reduced bite force capacities in favor of absolutely wider gapes compared to Eulemur in relation to their longer jaws. Importantly, our comparisons validate the simulated muscle approach for estimating bite force as a function of gape in extant and fossil primates.

Infant survival is significantly impacted by dam- and management-related factors in zoo-managed Eulemur populations.

Due to their potential impact on population growth, many studies have investigated factors affecting infant survival in mammal populations under human care. Here we used more than 30 years of Association of Zoos and Aquariums (AZA) studbook data and contraception data from the AZA Reproductive Management Center, along with logistic regression models, to investigate which factors affect infant survival in four Eulemur species managed as Species Survival Plans® in AZA. Across species, infant survival to 1 month ranged from 65% to 78%. Previous experience producing surviving offspring was positively correlated to infant survival in collared (Eulemur collaris), crowned (Eulemur coronatus), and mongoose (Eulemur mongoz) lemurs. Both dam age and previous use of contraception were negatively correlated to infant survival for collared lemurs, though our results suggest the latter may be confounded with other factors. Blue-eyed black lemurs (Eulemur flavifrons) were affected by birth location, suggesting differences in husbandry that may affect infant survival. These results can be used to assist in reproductive planning or to anticipate the likelihood of breeding success. Population managers may also be able to focus their reproductive planning on younger dams or those with previous experience to predict successful births. Future studies should seek to determine what aspects of previous dam success are most important to infant survival, investigate sire-related factors, and examine factors related to cause of death in infants that may lead to differential survival. Our hope is to present a framework that may be useful for investigating infant survival in other mammal species' breeding programs.

Rhythm May Be Key to Linking Language and Cognition in Young Infants: Evidence From Machine Learning.

Rhythm is key to language acquisition. Across languages, rhythmic features highlight fundamental linguistic elements of the sound stream and structural relations among them. A sensitivity to rhythmic features, which begins in utero, is evident at birth. What is less clear is whether rhythm supports infants' earliest links between language and cognition. Prior evidence has documented that for infants as young as 3 and 4 months, listening to their native language (English) supports the core cognitive capacity of object categorization. This precocious link is initially part of a broader template: listening to a non-native language from the same rhythmic class as (e.g., German, but not Cantonese) and to vocalizations of non-human primates (e.g., lemur, Eulemur macaco flavifrons, but not birds e.g., zebra-finches, Taeniopygia guttata) provide English-acquiring infants the same cognitive advantage as does listening to their native language. Here, we implement a machine-learning (ML) approach to ask whether there are acoustic properties, available on the surface of these vocalizations, that permit infants' to identify which vocalizations are candidate links to cognition. We provided the model with a robust sample of vocalizations that, from the vantage point of English-acquiring 4-month-olds, either support object categorization (English, German, lemur vocalizations) or fail to do so (Cantonese, zebra-finch vocalizations). We assess (a) whether supervised ML classification models can distinguish those vocalizations that support cognition from those that do not, and (b) which class(es) of acoustic features (including rhythmic, spectral envelope, and pitch features) best support that classification. Our analysis reveals that principal components derived from rhythm-relevant acoustic features were among the most robust in supporting the classification. Classifications performed using temporal envelope components were also robust. These new findings provide in principle evidence that infants' earliest links between vocalizations and cognition may be subserved by their perceptual sensitivity to rhythmic and spectral elements available on the surface of these vocalizations, and that these may guide infants' identification of candidate links to cognition.

Integrating the female masculinization and challenge hypotheses: Female dominance, male deference, and seasonal hormone fluctuations in adult blue-eyed black lemurs (Eulemur flavifrons)

In the decades since female social dominance was first described in strepsirrhine primates, researchers have sought to uncover the proximate and ultimate explanations for its development. In the females of various female-dominant species, androgens have been implicated as regulators of behavior and/or predictors of seasonal fluctuations in aggression (the ‘Female Masculinization Hypothesis’). Males, more generally, respond to changing social demands via seasonal fluctuations in androgen-mediated behavior (the ‘Challenge Hypothesis’), that may also entail changes in activation of the hypothalamic-pituitary-adrenal axis. Here, we explore if androgens, glucocorticoids, and intersexual behavior fluctuate seasonally in the female-dominant, blue-eyed black lemur (Eulemur flavifrons), with potential consequences for understanding female aggression and male deference. Across two studies conducted during the breeding and nonbreeding seasons, we assessed rates of mixed-sex, dyadic social behavior (aggression and affiliation) and concentrations of fecal glucocorticoid metabolites (Study 1) and serum sex hormones (androstenedione, testosterone, and estradiol; Study 2). Our results align with several predictions inspired by the Female Masculinization and Challenge Hypotheses for intersexual relations: During the breeding season, specifically, both aggression and androstenedione peaked in females, while female-initiated affiliation decreased, potentially to facilitate female resource access and reproductive control. By comparison, all target hormones (androgens, estrogen, and glucocorticoids) peaked in males, with glucocorticoid concentrations potentially increasing in response to the surge in female aggression, and unusually high estrogen concentrations year-round potentially facilitating male deference via male-initiated affiliation. These results suggest complex, seasonally and hormonally mediated behavior in Eulemur flavifrons.

Visualization and quantification of mimetic musculature via DiceCT.

The muscles of facial expression are of significant interest to studies of communicative behaviors. However, due to their small size and high integration with other facial tissues, the current literature is largely restricted to descriptions of the presence or absence of specific muscles. Using diffusible iodine-based contrast-enhanced computed tomography (DiceCT) to stain and digitally image the mimetic mask of Eulemur flavifrons (the blue-eyed black lemur), we demonstrate—for the first time—the ability to visualize these muscles in three-dimensional space and to measure their relative volumes. Comparing these data to earlier accounts of mimetic organization with the face of lemuroidea, we demonstrate several novel configurations within this taxon, particularly in the superior auriculolabialis and the posterior auricularis. We conclude that DiceCT facilitates the study these muscles in closer detail than has been previously possible, and offers significant potential for future studies of this anatomy.

Phylogenetic comparison on cognition: Advances in evolutionary psychology

More and more biological evidence has been yielded in support of physical evolution of species. In contrast, psychological evolution has been, so far, studied primarily with theoretical exploration. There are two theoretical approaches to the evolution on cognitive ability. The first, Common Ancestor, states that all species, including humans, have a common ancestor, from whom particular cognitive abilities in all existing species are inherited. The second, Evolutionary Convergence holds that different species possess similar cognitive abilities. The controversy between the two theories lies in the explanation of similar cognitive abilities in different species, one focusing on theoretical deduction and the other on parsimony in interpretation. However, both agree that basic cognitive abilities can be a starting point for studying the evolution on cognitive abilities. The top-down and the bottom-up approaches are usually used to study the cognitive abilities of different species. The top-down approach focuses on the cross-species levels of presence of a certain cognitive ability, and explores its level of presence among different species in relation to that in human beings. For the bottom-up approach, researchers generally analyze and study basic cognitive abilities, or the basic components of complex cognitive abilities, and systematically study the degree of difference between species in these basic cognitive abilities, which are universally present across species. The top-down approach can provide a precondition for defining the species boundaries of certain cognitive abilities, or which species have such abilities, while the bottom-up approach employs systematic methods to study the basic components of relevant cognitive abilities through cross-species experiments. The elaboration above suggests that we can understand the emergence and development of certain cognitive abilities, and the relationship between human’s advanced and basic cognitive abilities from the perspective of phylogenesis. Phylogenetic comparative methods are an important kind of bottom-up method. For a basic cognitive ability, the method of phylogenetic comparison is used to conduct cross-species experiments, so that the data obtained can be compared systematically. The results are of great significance for answering theoretical questions regarding cognitive evolution. For example, Amici and colleagues examined the ability of social inhibitory control in six primates (chimpanzees, bonobos, orangutans, gorillas, capuchin monkeys, and spider monkeys), and found that the level of fission-fusion dynamics could partially predict this ability. MacLean and colleagues studied the inhibitory control of 567 individuals from 36 species (birds and mammals), and showed that inhibitory control was positively correlated with absolute brain volume. Dietary breadth also predicted inhibitory control in the primate species studied. Jones and colleagues tested numerical cognition in three lemurs ( Lemur catta , Eulemur mongoz , and Eulemur Macaco flavifrons ), rhesus monkeys ( Macaca mulatta ), and human adults. They did not find any difference in nature among the four non-human groups in this ability. Specifically, the internal representation by all four non-humans was as predicted by the approximate number system and fit the linear representation model of the system. Cognitive differences among the five groups mainly lied in their numerical acuity, with humans having the lowest Weber fractions and the highest sensitivity. Chen improved their methods, tested humans in five age groups and golden snub-nosed monkeys ( Rhinopithecus roxellana ), and obtained findings consistent with those of the previous study. With the rise of cross-species systematic comparison, the latest trend of in-depth exploration into cognitive ability, research on phylogenesis on cognitive ability has entered a quantitative stage. Quantitative research on the relationship between evolutionary adaptive pressure and cognitive ability will help reveal patterns in the emergence and development on cognitive abilities in different species and even human beings.

Range and conservation updates for the Critically Endangered blue-eyed black lemur Eulemur flavifrons and the Vulnerable black lemur Eulemur macaco

AbstractThe Critically Endangered blue-eyed black lemur Eulemur flavifrons of north-western Madagascar is one of the most threatened primates. The majority of research and conservation efforts for the species have been restricted to the Sahamalaza Peninsula but there are unstudied and unprotected populations farther inland. The dearth of information regarding the transition between E. flavifrons and its parapatric sister species, the Vulnerable black lemur Eulemur macaco, and the possibility of a hybrid population complicates conservation planning for both species. We surveyed 29 forest fragments across both species’ ranges to investigate the boundary between the taxa, whether hybrids persist, and the threats to lemurs in the region. We found E. flavifrons in six fragments and E. macaco in 17. We never observed E. flavifrons and E. macaco in the same location and we found no conclusive evidence of hybrids. Three fragments in which E. flavifrons was present were north of the Andranomalaza River, which had previously been considered the barrier between the two species. Based on these observations and a literature review, we provide updated ranges, increasing the extent of occurrence (EOO) of E. flavifrons by 28.7% and reducing the EOO of E. macaco by 44.5%. We also evaluate the capacity of protected areas to conserve these lemurs. We recommend additional surveys and the implementation of an education programme in this region to help conserve both species.

Hand-rearing the critically endangered blue-eyed black lemur (Eulemur flavifrons): milk formula, feeding and socialisation protocols

The blue-eyed black lemur ( Eulemur flavifrons ) is critically endangered in the wild and managed by ex-situ programmes in zoos. The breeding success in the European population is low and within the last five years, there have only been three births that survived. To try to increase the rate of infant survival, a systematic hand-rearing protocol was developed in 2013 and used on five infants from two different females that did not properly raise their infants. Milk formula was created with a mix of human newborn formula and kitten replacement milk. The lemur infants were fed ten times a day at the beginning, on a 24-hour round-the-clock basis. Solid food was offered as early as Day 7 and complete weaning was achieved without any medical issues around Day 107. The socialisation protocol consisted of maintaining permanent visual, olfactory and auditory contact with the parents from the day of the birth. First attempts to put the infants on their mother began as early as Day 2, but results varied, including successes with the parents, with conspecifics or lemurs from another Eulemur species. More work is needed to develop a feeding protocol which would also include the physiological variations in milk composition during the lactation period. Although many studies and reports have described hand rearing mammals, and more specifically lemurs, none of them describe a successful and complete protocol for five infants of the critically endangered blue-eyed black lemur.

Evolutionary history inferred from the de novo assembly of a nonmodel organism, the blue-eyed black lemur.

Lemurs, the living primates most distantly related to humans, demonstrate incredible diversity in behaviour, life history patterns and adaptive traits. Although many lemur species are endangered within their native Madagascar, there is no high-quality genome assembly from this taxon, limiting population and conservation genetic studies. One critically endangered lemur is the blue-eyed black lemur Eulemur flavifrons. This species is fixed for blue irises, a convergent trait that evolved at least four times in primates and was subject to positive selection in humans, where 5′ regulatory variation of OCA2 explains most of the brown/blue eye colour differences. We built a de novo genome assembly for E. flavifrons, providing the most complete lemur genome to date, and a high confidence consensus sequence for close sister species E. macaco, the (brown-eyed) black lemur. From diversity and divergence patterns across the genomes, we estimated a recent split time of the two species (160 Kya) and temporal fluctuations in effective population sizes that accord with known environmental changes. By looking for regions of unusually low diversity, we identified potential signals of directional selection in E. flavifrons at MITF, a melanocyte development gene that regulates OCA2 and has previously been associated with variation in human iris colour, as well as at several other genes involved in melanin biosynthesis in mammals. Our study thus illustrates how whole-genome sequencing of a few individuals can illuminate the demographic and selection history of nonmodel species.

A preliminary population viability analysis of the critically endangered blue-eyed black lemur (Eulemur flavifrons)

Population viability analysis is an important tool to assess the extinction risk in small populations of highly specialized primates. The blue-eyed black lemur (Eulemur flavifrons) is critically endangered with a restricted range in the north-western dry deciduous forest of Madagascar, where habitat fragmentation and loss of forest connectivity threaten its survival. We performed a population viability analysis (PVA) of this lemur in Ankarafa Forest in the Sahamalaza Peninsula National Park, north-western Madagascar, to determine the demographic parameters most influential for population persistence and to assess extinction probabilities. We conducted PVA analyses using different demographic parameters which characterize the species including reproduction, lifespan and population size using the software VORTEX for six scenarios with 100 iterations and simulated over 100 years. The simulations suggested the first extinction within 13 years when the percentage of habitat destruction increased up to 12%. Severe habitat destruction such as fire and logging was the major cause which led to the risk of population extinction. Conservation strategies, in particular measures to reduce habitat destruction, are proposed to ensure the survival of this critically endangered lemur. Une Analyse de viabilité de population (AVP) est un outil important pour évaluer le risque d'extinction de petites populations de primates très spécialisés. Le lémur aux yeux turquoise (Eulemur flavifrons) est en danger critique d'extinction, avec une aire de répartition qui se limite à une forêt sèche décidue du nord-ouest de Madagascar, où la fragmentation de l'habitat et la perte de connectivité de la forêt menacent sa survie. Nous avons réalisé une AVP de ce lémurien dans la forêt d'Ankarafa, dans le Parc National de la Péninsule de Sahamalaza, au nord-ouest de Madagascar, pour déterminer quels étaient les paramètres démographiques qui avaient le plus d'influence sur le maintien de la population et pour évaluer ses probabilités d'extinction. Nous avons fait des AVP en nous servant de différents paramètres démographiques qui caractérisent cette espèce, comme la reproduction, la durée de vie et la taille de la population, en utilisant le logiciel VORTEX pour six scénarios, avec 100 itérations, simulés sur 100 ans. Les simulations suggéraient la première extinction dans 13 ans, lorsque le pourcentage de destruction de l'habitat passait à 12%. Une grave destruction de l'habitat, par le feu ou les coupes d'arbres, était la cause majeure conduisant au risque d'extinction de la population. Des stratégies de conservation, en particulier des mesures pour réduire la destruction de l'habitat, sont proposées pour assurer la survie de ce lémur en danger critique d'extinction.

Structure and Composition of Ankarafa Forest, Sahamalaza-Iles Radama National Park, Madagascar: Implications for the Frugivorous Endemic Blue-Eyed Black Lemur (Eulemur flavifrons)

The composition, structure and distribution of forest trees in Ankarafa Forest in the Sahamalaza-Iles Radama National Park, Madagascar, were evaluated to determine the influence of their fruiting on the seasonal feeding/foraging ecology of the mainly frugivorous, endemic blue-eyed black lemur (Eulemur flavifrons). Plots were sampled within the forest core and on the forest edges. A total of 848 live trees belonging to 42 species, 39 genera and 28 families were recorded. Ankarafa Forest is dominated by Mangifera indica (an exotic), Garcinia pauciflora, Sorindeia madagascariensis, Grangeria porosa, bamboo spp. and Mascarenhasia arborescens. More than 20% of the stems counted were exotic, long-lived species which has a negative consequence for future forest dynamics. In particular the predominance of the exotic M. indica has negative implications for fruit availability at the end of the dry season and during the wet season. Canopy height was lower than most tropical forests but similar to other Malagasy forests with an average tree height of 10 ± 3.6 m and a mean diameter at breast height of 13.8 ± 11.7 cm. Height and diameter of trees differed significantly between the edge and core of the forest. However, most trees were between 5 and 15 m high, and most of smaller diameter, both at the edge and core, suggesting it is a complex system. Along the forest edge, many trees were burnt by uncontrolled fire. Trees felled by cyclones were recorded both on the edge and in the core of the forest. Fruit availability was similar throughout the forest on a spatial scale, but differed temporally. Being relatively high in tree species diversity, Ankarafa Forest needs to be protected to continue to support its endemic fauna, particularly those with restricted distribution such as the blue-eyed black lemur. In particular, further forest degradation and fragmentation needs to be avoided.

Lemurs and macaques show similar numerical sensitivity

We investigated the precision of the approximate number system (ANS) in three lemur species (Lemur catta, Eulemur mongoz, and Eulemur macaco flavifrons), one Old World monkey species (Macaca mulatta) and humans (Homo sapiens). In Experiment 1, four individuals of each nonhuman primate species were trained to select the numerically larger of two visual arrays on a touchscreen. We estimated numerical acuity by modeling Weber fractions (w) and found quantitatively equivalent performance among all four nonhuman primate species. In Experiment 2, we tested adult humans in a similar procedure, and they outperformed the four nonhuman species but showed qualitatively similar performance. These results indicate that the ANS is conserved over the primate order.

Interspecific semantic alarm call recognition in the solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis.

As alarm calls indicate the presence of predators, the correct interpretation of alarm calls, including those of other species, is essential for predator avoidance. Conversely, communication calls of other species might indicate the perceived absence of a predator and hence allow a reduction in vigilance. This “eavesdropping” was demonstrated in birds and mammals, including lemur species. Interspecific communication between taxonomic groups has so far been reported in some reptiles and mammals, including three primate species. So far, neither semantic nor interspecific communication has been tested in a solitary and nocturnal lemur species. The aim of this study was to investigate if the nocturnal and solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis, is able to access semantic information of sympatric species. During the day, this species faces the risk of falling prey to aerial and terrestrial predators and therefore shows high levels of vigilance. We presented alarm calls of the crested coua, the Madagascar magpie-robin and aerial, terrestrial and agitation alarm calls of the blue-eyed black lemur to 19 individual Sahamalaza sportive lemurs resting in tree holes. Songs of both bird species’ and contact calls of the blue-eyed black lemur were used as a control. After alarm calls of crested coua, Madagascar magpie-robin and aerial alarm of the blue-eyed black lemur, the lemurs scanned up and their vigilance increased significantly. After presentation of terrestrial alarm and agitation calls of the blue-eyed black lemur, the animals did not show significant changes in scanning direction or in the duration of vigilance. Sportive lemur vigilance decreased after playbacks of songs of the bird species and contact calls of blue-eyed black lemurs. Our results indicate that the Sahamalaza sportive lemur is capable of using information on predator presence as well as predator type of different sympatric species, using their referential signals to detect predators early, and that the lemurs’ reactions are based on experience and learning.

The convergent evolution of blue iris pigmentation in primates took distinct molecular paths

How many distinct molecular paths lead to the same phenotype? One approach to this question has been to examine the genetic basis of convergent traits, which likely evolved repeatedly under a shared selective pressure. We investigated the convergent phenotype of blue iris pigmentation, which has arisen independently in four primate lineages: humans, blue-eyed black lemurs, Japanese macaques, and spider monkeys. Characterizing the phenotype across these species, we found that the variation within the blue-eyed subsets of each species occupies strongly overlapping regions of CIE L*a*b* color space. Yet whereas Japanese macaques and humans display continuous variation, the phenotypes of blue-eyed black lemurs and their sister species (whose irises are brown) occupy more clustered subspaces. Variation in an enhancer of OCA2 is primarily responsible for the phenotypic difference between humans with blue and brown irises. In the orthologous region, we found no variant that distinguishes the two lemur species or associates with quantitative phenotypic variation in Japanese macaques. Given the high similarity between the blue iris phenotypes in these species and that in humans, this finding implies that evolution has used different molecular paths to reach the same end. Am J Phys Anthropol 151:398–407, 2013.© 2013 Wiley Periodicals, Inc.

Life history traits, maternal behavior and infant development of blue‐eyed black lemurs (Eulemur flavifrons)

An understanding of recruitment is important for estimating population growth and viability, and their implications for conservation. We present the first results regarding the life history, maternal behavior and infant development of the critically endangered blue-eyed black lemur (Eulemur flavifrons) of Madagascar. The species breeds seasonally, with births occurring at the end of the dry season, between late August and October. Over two successive birth seasons in 2006 and 2007, we observed a total of 13 lactating females and 22 infants from six groups. We inferred age at first reproduction as 3 years, and calculated the birth rate as 1.0 infant per female per year with a mean inter-birth interval of 358 ± 24.81 days (319-410 days). Infants spent the first 3 weeks of life constantly with their mothers; locomotor independence and ingestion of solid food began at week 10, and the infants were weaned by week 25. After week 28, infants spent less than 20% of their time in contact with their mothers. Over the study period infant mortality was 22.7%, with predation and sickness observed as causes. Our results suggest that overall recruitment is relatively slow, which has implications for the species' survival, particularly given their restricted and threatened habitat.

A Population Estimate of Blue-Eyed Black Lemurs in Ankarafa Forest, Sahamalaza-Iles Radama National Park, Madagascar

The critically endangered blue-eyed black lemur (Eulemur flavifrons) has one of the smallest distributions of any lemur, occurring only in the north-western forests of Madagascar. We report the results of a population estimate of this taxon in part of the Ankarafa Forest, Sahamalaza-Iles Radama National Park, a dry deciduous forest. We collected data between September 2007 and February 2008 using a total count method with marked individuals and known groups. In all, 228 individuals comprising 29 groups were counted. Group sizes ranged from 4 to 11 individuals with a mean of 8 ± 1.8. We estimated population density to be 1.0 individual/ha or 97.3 individuals/km² for our study area, which is higher than previous estimates reported for Ankarafa and other sites within the Sahamalaza Peninsula. Our mean group size, however, was similar to those determined in previous studies. Both group size and density of the blue-eyed black lemur were higher within the National Park than in previous studies outside the Park.

A 12-Month Survey of Gastrointestinal Helminth Infections of Lemurs Kept in Two Zoos in Madagascar

Infections with gastrointestinal parasites may be a major threat to lemurs kept in captivity, as they are a common cause of diarrhea. In this study, fecal egg count patterns and clinical signs associated with gastrointestinal nematodes were assessed for 12 mo in 40 lemurs kept under different husbandry and climatic conditions at two sites in Madagascar. Involved species were black-and-white ruffed lemurs (Varecia variegata), eastern grey bamboo lemurs (Hapalemur griseus), greater bamboo lemurs (Prolemur simus), red-bellied lemurs (Eulemur rubriventer), common brown lemurs (Eulemurfulvus), crowned lemurs (Eulemur coronatus), and Sclater's black lemurs (Eulemur macaco flavifrons). At site 1 (Tsimbazaza Zoological Park), lemurs were kept in small enclosures with daily cleaning of the cement soiling and without routine anthelmintic program, whereas at site 2 (Ivoloina Zoological Park), lemurs received routine anthelmintic prophylaxis and were housed in small enclosure with daily cleaning of sandy soil enclosures. A total of five genera of nematode eggs from the orders Strongylida, Oxyurida, and Enoplida were recovered and identified from 198 out of 240 samples (83%) at site 1 and 79% (189 out of 240) at site 2 with the use of a modified McMaster technique. Significant differences were found for parasites from the order Strongylida between the two sites. The differences may be due to climate conditions and the presumed life cycle of these parasites. No significant differences were found for parasites from the other orders. No significant differences were noted between sexes or between seasons. No clinical signs of parasitic gastroenteritis were seen in either lemur collection.

Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 12:215-225 (2010) - DOI: https://doi.org/10.3354/esr00304 Contribution to the Theme Section 'Responses of animals to habitat alteration' Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments Nora Schwitzer1,4, Dagmar Clough2, Horst Zahner1, Werner Kaumanns3, Peter Kappeler2, Christoph Schwitzer4,* 1Institut für Parasitologie, Justus-Liebig-Universität, Rudolf-Buchheim-Strasse 2, 35392 Giessen, Germany 2Abteilung Verhaltensökologie & Soziobiologie/Anthropologie, Deutsches Primatenzentrum, Kellnerweg 4, 37077 Göttingen, Germany 3Eschenweg 5, 37130 Gleichen, Germany 4Bristol Conservation and Science Foundation, Bristol Zoo Gardens, Clifton, Bristol BS8 3HA, UK *Corresponding author. Email: cschwitzer@bristolzoo.org.uk ABSTRACT: The parasite burden of an animal population has frequently been used as an indicator of the stress level to which the population is exposed. Primates inhabiting small forest fragments are more likely to experience human contact, reduced food availability and restricted ranging—any or all of which may contribute to a higher parasite prevalence—than populations inhabiting intact primary forest. Recent and ongoing human exploitation of otherwise intact forest may also affect disease burden and parasite transmission in primates. The parasites of blue-eyed black lemurs Eulemur flavifrons have not as yet been subject to scientific research. This paper describes the various parasites found in E. flavifrons and shows parasite prevalence in lemur groups living in differently degraded fragments of the Ankarafa Forest in Sahamalaza National Park, northwest Madagascar. We analysed 166 faecal samples of E. flavifrons inhabiting primary forest and 168 from groups inhabiting secondary forest. In addition, faecal samples and ectoparasites were collected from 18 immobilised lemurs. Forty-three (12.9%) samples contained parasite eggs (Lemuricola spp. and Callistoura spp.) or oocysts. Ten (55.6%) of the 18 samples from immobilised lemurs contained adult Lemuricola spp. Parasite prevalence was significantly higher in secondary than in primary forest, at 7.9 and 4.8% of all positive samples, respectively. Prevalence was high when compared to other studies on parasite load in wild lemurs, suggesting that in our survey area, E. flavifrons were generally under pressure, possibly due to the high degree of fragmentation and degradation of the remaining forest habitat. KEY WORDS: Eulemur flavifrons · Primary forest · Secondary forest · Lemuricola · Callistoura · Seasonality Full text in pdf format PreviousNextCite this article as: Schwitzer N, Clough D, Zahner H, Kaumanns W, Kappeler P, Schwitzer C (2010) Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments. Endang Species Res 12:215-225. https://doi.org/10.3354/esr00304Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 12, No. 3. Online publication date: September 20, 2010 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2010 Inter-Research.

Home range size in the blue-eyed black lemur ( Eulemur flavifrons): A comparison between dry and wet seasons

Western Madagascar is subjected to a long, dry winter season which coincides with food scarcity. We investigated the effect of this seasonal variation in food availability on the home ranges of blue-eyed black lemurs ( Eulemur flavifrons) in the Sahamalaza-Iles Radama National Park, north-western Madagascar. It was expected that home range would increase and overlap more in the dry season. The study was conducted in an area of dry rainforest from September 2006 to March 2008 with five lemur groups. Animals were located by direct observation and geographical locations recorded to determine the daily path length and the home range sizes of the study groups in the respective seasons. Daily path length and home range size varied significantly between seasons. Daily path length was significantly greater in the dry season (673.4 ± 539.2 m) than in the wet season (423.6 ± 183.2 m). Home ranges overlapped between groups in both seasons, but were significantly larger during the dry season (MCP: 7.5 ± 6.6 ha, 95% Kernel: 8.5 ± 6.6 ha) than in the wet season (MCP: 3.0 ± 1.6 ha, 95% Kernel: 4.1 ± 1.6 ha). There was no clear relationship between home range size and group size in either the dry or the wet season. Seasonal changes in home range area are likely to be a consequence of reduced food availability in the dry season. Compared to other primates, including some lemur species, the home range size of the blue-eyed black lemur is relatively small.