Explore the vast range of titles available.

Time is considered a resource in limited supply, and temporal niche separation is one of the most common strategies that allow ecologically similar species to live in sympatry. Mechanisms of temporal niche separation are understudied especially in cryptic animals due to logistical problems in gathering adequate data. Using high-frequency accelerometers attached to radio-collars, we investigated whether the ecologically similar lemurs Avahi meridionalis and Lepilemur fleuretae in the lowland rainforest of Tsitongambarika, south-eastern Madagascar, show temporal niche separation. Accelerometers stored data with a frequency of 1 Hz for a total of 71 days on three individuals of A. meridionalis and three individuals of L. fleuretae. We extrapolated motor activity patterns via the unsupervised learning algorithm expectation maximisation and validated the results with systematic behavioural observations. Avahi meridionalis showed peaks of activity at twilights with low but consistent activity during the day, while L. fleuretae exhibited more activity in the central hours of the night. Both lemur species had their activity pattern entrained by photoperiodic variations. The pair-living A. meridionalis was found to be lunarphilic while the solitary-living L. fleuretae was lunarphobic. We suggest that these activity differences were advantageous to minimise feeding competition, as an anti-predator strategy, and/or for dietary-related benefits. These findings demonstrate a fine-tuned temporal partitioning in sympatric, ecologically similar lemur species and support the idea that an activity spread over the 24-h, defined here as cathemerality sensu lato, is more common than previously thought in lemurs.

Subsistence hunting presents a conservation challenge by which biodiversity preservation must be balanced with safeguarding of human livelihoods. Globally, subsistence hunting threatens primate populations, including Madagascar’s endemic lemurs. We used population viability analysis to assess the sustainability of lemur hunting in Makira Natural Park, Madagascar. We identified trends in seasonal hunting of 11 Makira lemur species from household interview data, estimated local lemur densities in populations adjacent to focal villages via transect surveys, and quantified extinction vulnerability for these populations based on species-specific demographic parameters and empirically derived hunting rates. We compared stagebased Lefkovitch with periodic Leslie matrices to evaluate the impact of regional dispersal on persistence trajectories and explored the consequences of perturbations to the timing of peak hunting relative to the lemur birth pulse, under assumptions of density-dependent reproductive compensation. Lemur hunting peaked during the fruit-abundant wet season (March–June). Estimated local lemur densities were roughly inverse to body size across our study area. Life-history modeling indicated that hunting most severely threatened the species with the largest bodies (i.e., Hapalemur occidentalis, Avahi laniger, Daubentonia madagascariensis, and Indri indi), characterized by late-age reproductive onsets and long interbirth intervals. In model simulations, lemur dispersal within a regional metapopulation buffered extinction threats when a majority of local sites supported growth rates above the replacement level but drove regional extirpations when most local sites were overharvested. Hunt simulations were most detrimental when timed to overlap lemur births (a reality for D. madagascariensis and I. indri). In sum, Makira lemurs were overharvested. Regional extirpations, which may contribute to broad-scale extinctions, will be likely if current hunting rates persist. Cessation of anthropogenic lemur harvest is a conservation priority, and development programs are needed to help communities switch from wildlife consumption to domestic protein alternatives. La caza de subsistencia representa un reto de conservación ante el cual la preservación de la biodiversidad debe balancearse con la salvaguardia del sustento humano. A nivel mundial, la caza de subsistencia amenaza a las poblaciones de primates, incluyendo a los lémures endémicos de Madagascar. Usamos análisis de viabilidad poblacional (PVA, en inglés) para evaluar la sustentabilidad de la caza de lémures en el Parque Natural Makira, Madagascar. Identificamos tendencias en la caza estacional de 11 especies de lémur en Makira a partir de información obtenida con entrevistas a hogares, estimamos las densidades locales de lémures en las poblaciones adyacentes a aldeas focales por medio de censos de transecto, y cuantificamos la vulnerabilidad a la extinción para estas poblaciones con base en parámetros demográficos específicos por especie y las tasas de caza derivadas empíricamente. Comparamos el modelo Lefkovitch basado en estadios con matrices periódicas de Leslie para evaluar el impacto de la dispersión regional sobre las trayectorias de persistencia y exploramos las consecuencias de las perturbaciones al momento justo del punto máximo de caza en relación con el pulso de nacimiento de lémures, bajo suposición de la compensación reproductiva dependiente de la densidad. La caza de lémures alcanzó su puntomáximodurante la temporada lluviosa con abundancia de frutos (marzo – junio). Las densidades locales estimadas de lémures fueron aproximadamente inversas al tamaño corporal a lo largo de nuestra área de estudio. El modelado de historias de vida indicóque la caza amenazó con mayor severidad a las especies con tallas mayores (es decir, Hapalemur occidentalis, Avahi laniger, Daubentonia madagascariensis, Indri indri), caracterizadas por tener un arranque reproductivo a una edad tardía e intervalos largos entre nacimientos. En las simulaciones modeladas, la dispersión de los lémures dentro de una metapoblación regional amortiguó las amenazasde extinción cuando una mayoría de sitios locales respaldó las tasas de crecimiento por encima del nivel de reemplazo pero condujo a las extirpaciones locales cuando la mayoría de los sitios tuvo sobreexplotación. Las simulaciones de caza fueron más nocivas cuando se programaron para sobreponerse a los nacimientos de lémures x(una realidad para D. madagascariensis e I. indri). En resumen, existe una sobreexplotación de lémures en Makira. Las extirpaciones regionales, las cuales pueden contribuir a las extinciones a escala general, serán probables sí las tasas de caza actuales continúan. El cese de explotación humana de lémures es una prioridad para la conservación, y se necesitan programas de desarrollo para ayudar a las comunidades a cambiar el consumo de fauna silvestre por alternativas domésticas de proteína. 生计狩猎是保护工作的ー项挑故， 它要求保护生物多祥性必须与保障人类生计相平衡。全球的灵长 类动觀包括马达加斯加特有的狐猴，都面临着生计狩猎的威胁。我们用种群生存力分析评估了马达加斯 加 Makira 自然公园狐猴狩猎的可持续性。利用访问调查的数瑕我们确定了Maktra自然公园 11 种狐猴面搞 的季节性狩猎态勢，并通过样带调查估计了村庄附近狐猴的局域种群密度，还根据物种特异的种群参数和狩猎率 经验值量化了这些种群灭绝的脆弱性。我们比较了基于阶段的 Lefkovitch 矩阵与周期性的 Leslie 矩阵，以评估 区域性扩散对种群续存的影响，还在密度依赖性繁殖补偿的假设下探讨了狩猎高峰期相对于狐猴出生潮发生扰 动所带来的影响。水果丰富的雨季（三月到六月）是狩猎狐猴的高峰期。在我们的研究区域，区域狐猴密度的 估计值大致与体型大小成反比。生活史建模表明，体型最大的物种伽 Hapalemur occidentalism Avahi laniger, Daubentonia madagascariensis 和 Indriindt)受狩猎威胁最为严重，这些物神多具有开始繁殖的年龄晚、繁 殖间隔长的特点。在模型模拟中，当大多数局部位点的种群增长率高于更替水平时，区域集合种群中狐猴的扩 散可以缓冲灭绝的威胁，而当大多数位点都受到过度狩猎时，扩散则会导致区域性灭绝。当狩猎与狐猴出生时 间重合时，模拟得出狩猎的危害最大 (D. madagascariensis和I. tndri的真实情况如此))。 总的来说M akira自然 公园的狐猴已受到过度狩猎。如果维持现有的狩猎率狐猴可能会发生区域性灭绝，进而导致大范围的灭绝。目 前的保护重点是停止人类对狐猴的狩猎行为，需要推动发展计划来帮助当地社区居民从野生动物转向以家畜作 为肉类食物来源.

Habitat loss and fragmentation pose a significant threat to many primate species worldwide, yet community-level responses are complex and nuanced. Despite repeated calls from primatologists and the wider conservation community to increase monitoring initiatives that assess long-term population dynamics, such studies remain rare. Here we summarize results from a longitudinal study set in the littoral forests of southeast Madagascar. Littoral forests are a useful model for monitoring lemur population dynamics, as they are relatively well studied and their highly fragmented nature enables the effect of forest size and anthropogenic impacts to be examined. This study focuses on three Endangered nocturnal lemur species—Avahi meridionalis, Cheirogaleus thomasi, and Microcebus tanosi—across three forest fragments of different size and with different usage histories. Between 2011 and 2018, we walked 285 km of line transect and recorded 1968 lemur observations. Based on distance sampling analysis our results indicate that nocturnal lemurs respond to forest patch size and to levels of forest degradation in species-specific ways. The largest species, A. meridionalis, declined in density and encounter rate over time across the three study forests. C. thomasi populations appeared stable in all three fragments, with densities increasing in the most degraded forest. M. tanosi encounter rates were extremely low across all study fragments but were lowest in the most heavily degraded forest fragment. Our results emphasize the importance of localized pressures and species-specific responses on population dynamics. Monitoring population trends can provide an early warning signal of species loss and species-specific responses can inform crucial intervention strategies.

Forest loss, fragmentation, and anthropization threaten the survival of forest species all over the world. Shifting agriculture is one of these threatening processes in Madagascar. However, when its cycle is halted and the land is left to regenerate, the resulting growth of secondary forest may provide a viable habitat for folivorous and omnivorous lemur species. We aimed to identify the response of nocturnal lemurs to different successional stages of regenerating secondary, degraded mature, and mature forest across a mosaic-type landscape. We surveyed four nocturnal lemur species (Avahi laniger, Microcebus cf. simmonsi, Allocebus trichotis, and Daubentonia madagascariensis) in four forest types of varying habitat disturbance in northeastern Madagascar. We estimated densities in mature and regenerating secondary forest for the eastern woolly lemur (Avahi laniger) and mouse lemur (Microcebus cf. simmonsi), two sympatric species with folivorous and omnivorous diets respectively. We did not estimate densities of Allocebus trichotis and Daubentonia madagascariensis owing to small sample size; however, we observed both species exclusively in mature forest. We found higher population densities of A. laniger and M. cf. simmonsi in secondary than in mature forest, showing the potential of regenerating secondary forest for lemur conservation. Several environmental factors influenced the detectability of the two lemur species. While observer and habitat type influenced detection of the eastern woolly lemur, canopy height and vine density influenced detection of mouse lemurs. Understanding how different species with different diets interact with anthropogenically impacted habitat will aid future management decisions for the conservation of primate species.

Transposable elements provide a highly informative marker system for analyzing evolutionary histories. To solve controversially discussed topics in strepsirrhine phylogeny, we characterized 61 loci containing short interspersed elements (SINEs) and determined the SINE presence-absence pattern at orthologous loci in a representative strepsirrhine panel. This SINE monolocus study was complemented by a Southern blot analysis tracing multiple loci of two different strepsirrhine specific SINEs. The results thereof were combined with phylogenetic trees reconstructed on the basis of complete mitochondrial cytochrome b sequences from all recognized strepsirrhine genera. Here we present evidence for (i) a sister group relationship of Malagasy Chiromyiformes and Lemuriformes, (ii) Lorisidae being a monophyletic sister clade to the Galagidae, and (iii) common ancestry of African and Asian lorisids. Based on these findings, we conclude that strepsirrhines originated in Africa and that Madagascar and Asia were colonized by respective single immigration events. In agreement with paleocontinental data, the molecular analyses suggest a crossing of the Mozambique channel by rafting between the late Cretaceous and the middle Eocene, whereas Asia was most likely colonized between the early Eocene and the middle Oligocene on a continental route. Furthermore, one SINE integration links the two Lemuriformes families, Lemuridae and Indriidae, indicating a common origin of diurnality or cathemerality and a later reversal to nocturnality by the indriid genus Avahi.

Numerous researchers have posited that there should be a strong negative relationship between the evolutionary distance among species and their ecological similarity. Alternative evidence suggests that members of adaptive radiations should display no relationship between divergence time and ecological similarity because rapid evolution results in near-simultaneous speciation early in the clade's history. In this paper, we performed the first investigation of ecological diversity in a phylogenetic context using a mammalian adaptive radiation, the Malagasy primates. We collected data for 43 extant species including: 1) 1064 species by locality samples, 2) GIS climate data for each sampling locality, and 3) the phylogenetic relationships of the species. We calculated the niche space of each species by summarizing the climatic variation at localities of known occurrence. Climate data from all species occurrences at all sites were entered into a principal components analysis. We calculated the mean value of the first two PCA axes, representing rainfall and temperature diversity, for each species. We calculated the K statistic using the Physig program for Matlab to examine how well the climatic niche space of species was correlated with phylogeny. We found that there was little relationship between the phylogenetic distance of Malagasy primates and their rainfall and temperature niche space, i.e., closely related species tend to occupy different climatic niches. Furthermore, several species from different genera converged on a similar climatic niche. These results have important implications for the evolution of ecological diversity, and the long-term survival of these endangered species.

Madagascar is one of the world’s biodiversity hotspots. The island’s past and current rates of deforestation and habitat disturbance threaten its plethora of endemic biodiversity. On Madagascar, tavy (slash and burn agriculture), land conversion for rice cultivation, illegal hardwood logging and bushmeat hunting are the major contributors to habitat disturbance. Understanding species-specific responses to habitat disturbance across different habitat types is crucial when designing conservation strategies. We surveyed three nocturnal lemur species in four forest types of varying habitat disturbance on the Masoala Peninsula, northeastern Madagascar. We present here updated abundance and density estimates for the Endangered Avahi mooreorum and Lepilemur scottorum, and Microcebus sp. Distance sampling surveys were conducted on 11 transects, covering a total of 33 km after repeated transect walks. We collected data on tree height, bole height, diameter at breast height, canopy cover and tree density using point-quarter sampling to characterise the four forest types (primary lowland, primary littoral, selectively logged and agricultural mosaic). Median encounter rates by forest type ranged from 1 to 1.5 individuals (ind.)/km ( Microcebus sp.), 0–1 ind./km ( A. mooreorum ) and 0–1 ind./km ( L. scottorum ). Species density estimates were calculated at 232.31 ind./km 2 ( Microcebus sp.) and 121.21 ind./km 2 ( A. mooreorum ), while no density estimate is provided for L. scottorum due to a small sample size. Microcebus sp. was most tolerant to habitat disturbance, exhibiting no significant effect of forest type on abundance. Its small body size, omnivorous diet and generalised locomotion appear to allow it to tolerate a variety of habitat disturbance. Both A. mooreorum and L. scottorum showed significant effects of forest type on their respective abundance. This study suggests that the specialist locomotion and diet of A. mooreorum and L. scottorum make them susceptible to the effects of increasing habitat disturbance.

Extractive industries can have significant impacts on ecosystems through loss of habitat, degradation of water quality, and direct impact on floral and faunal biodiversity. When operations are located in sensitive regions with high biodiversity containing endangered or threatened species, it is possible to minimize impact on the environment by developing programs to scientifically monitor the impact on resident flora and fauna species in the early phases of operation so that effects can be mitigated whenever possible. This report presents the baseline health, nutrition, and trace mineral evaluation for 33 Avahi laniger (Eastern wooly lemur) and 15 Lepilemur mustelinus (greater sportive lemur) captured and given complete health evaluations that included the measurement of fat-soluble vitamins and trace minerals in addition to routine complete blood counts, serum chemistries, and parasite evaluations. All lemurs appeared healthy on physical examination despite the presence of minor wounds consistent with interspecies aggression in some individuals. Serum chemistry values were within expected ranges for other lemur species; however, A. laniger erythrocytes were significantly smaller than those of L. mustelinus. Serum nickel values were markedly higher than expected in both species, and selenium, copper, and cobalt levels were higher in L. mustelinus compared with A. laniger at the study site, as well as values for I. indri or P. diadema reported from other locations. Endoparasites and ectoparasites were typical of those reported in other wild lemur species, but load and diversity varied between A. laniger and L. mustelinus despite inhabiting the same forest ecosystem. This baseline assessment provides the foundation for ongoing monitoring.

Background A central question in evolutionary parasitology is to what extent ecology impacts patterns of parasitism in wild host populations. In this study, we aim to disentangle factors influencing the risk of parasite exposure by exploring the impact of sleeping site ecology on infection with ectoparasites and vector-borne hemoparasites in two sympatric primates endemic to Madagascar. Both species live in the same dry deciduous forest of northwestern Madagascar and cope with the same climatic constraints, they are arboreal, nocturnal, cat-sized and pair-living but differ prominently in sleeping site ecology. The Western woolly lemur ( Avahi occidentalis ) sleeps on open branches and frequently changes sleeping sites, whereas the Milne-Edward’s sportive lemur ( Lepilemur edwardsi ) uses tree holes, displaying strong sleeping site fidelity. Sleeping in tree holes should confer protection from mosquito-borne hemoparasites, but should enhance the risk for ectoparasite infestation with mites and nest-adapted ticks. Sex may affect parasite risk in both species comparably, with males bearing a higher risk than females due to an immunosuppressive effect of higher testosterone levels in males or to sex-specific behavior. To explore these hypotheses, ectoparasites and blood samples were collected from 22 individuals of A. occidentalis and 26 individuals of L. edwardsi during the dry and rainy season. Results L. edwardsi, but not A. occidentalis , harbored ectoparasites, namely ticks ( Haemaphysalis lemuris [Ixodidae], Ornithodoros sp. [Argasidae]) and mites ( Aetholaelaps trilyssa , [Laelapidae]), suggesting that sleeping in tree holes promotes infestation with ectoparasites. Interestingly, ectoparasites were found solely in the hot, rainy season with a prevalence of 75% ( N  = 16 animals). Blood smears were screened for the presence and infection intensity of hemoparasites. Microfilariae were detected in both species. Morphological characteristics suggested that each lemur species harbored two different filarial species. Prevalence of microfilarial infection was significantly lower in L. edwardsi than in A. occidentalis. No significant difference in infection intensity between the two host species, and no effect of season, daytime of sampling or sex on prevalence or infection intensity was found. In neither host species, parasite infection showed an influence on body weight as an indicator for body condition. Conclusions Our findings support that sleeping site ecology affects ectoparasite infestation in nocturnal, arboreal mammalian hosts in the tropics, whereas there is no significant effect of host sex. The influence of sleeping site ecology to vector-borne hemoparasite risk is less pronounced. The observed parasite infections did not affect body condition and thus may be of minor importance for shaping reproductive fitness. Findings provide first evidence for the specific relevance of sleeping site ecology on parasitism in arboreal and social mammals. Further, our results increase the sparse knowledge on ecological drivers of primate host-parasite interactions and transmission pathways in natural tropical environments.

Background Various factors, such as climate, body size and sociality are often linked to parasitism. This constrains the identification of other determinants driving parasite infections. Here, we investigate for the first time intestinal parasites in two sympatric arboreal primate species, which share similar activity patterns, feeding ecology, body size and sociality, and cope with the same climate conditions, but differ in sleeping site ecology: the Milne-Edward’s sportive lemur ( Lepilemur edwardsi ) and the Western woolly lemur ( Avahi occidentalis ). Comparison of these two species aimed to test whether differences in sleeping sites are related to differences in parasite infection patterns. Additionally, gender and seasonal factors were taken into account. Animals were radio-collared to record their sleeping site dynamics and to collect fecal samples to assess intestinal parasitism during both the dry and the rainy season. Results Only low parasite diversity was detected, which is attributable to the strict arboreal lifestyle of these lemurs, limiting their contact with infective parasite stages. L. edwardsi , which sleeps in tree holes and repeatedly uses the same sleeping site, excreted eggs of strongyle and oxyurid nematodes, whereby strongyles always occurred in coinfection with oxyurids. In contrast, A. occidentalis , which sleeps on open branches and frequently changes sleeping sites, only excreted eggs of strongyle nematodes. This difference can be attributed to a potential favorable environment presented by tree holes for infective stages, facilitating parasitic transmission. Additionally, Strongylida in A. occidentalis were only observed in the rainy season, suggesting an arrested development during the dry season in the nematodes’ life cycle. Males and females of both lemur species showed the same frequency of parasitism. No differences in body mass of infected and non-infected individuals were observed, indicating that the animals’ body condition remains unaffected by the detected gastrointestinal parasites. Conclusions The comparison of two primate hosts with a very similar lifestyle suggests an influence of the sleeping site ecology on intestinal parasites. In A. occidentalis there was a clear seasonal difference in strongyle egg excretion. These results improve our understanding of the parasite ecology in these endangered primate species, which may be critical in the light of species conservation.