20 research outputs found

    Behavioural ecology and conservation of the Anosy mouse lemur (Microcebus tanost) in the littoral forests of southeastern Madagascar

    Get PDF
    Mouse lemurs are widely regarded as an ideal model taxa to study behavioural ecology, sociality and evolution in primates, however relatively few recognised forms have been studied to date. The principal aim of this work is to investigate the behavioural and ecological character of the Anosy mouse lemur (Microcebus tanosi) and to relate these new insights to species conservation in the littoral forests of Sainte Luce. The littoral forests of southeast Madagascar represent a distinct phytogeographic habitat, characterised by tremendous species richness and floristic diversity, however, they have been severely impacted by human activities over the past century. At the outset, very little ecological data was available for M. tanosi. Across five data chapters I investigate the species' broad morphological flexibility, its ranging behaviour and social system, sleeping and nesting behaviours and its long-term demographic descriptives. I go on to contextualise the wider conservation challenges facing littoral biodiversity in Sainte Luce. This study finds no evidence for sexual dimorphism but detects subtle morphological differences between isolated con-specific populations. Microcebus tanosi home ranges overlap substantially both inter and intra-sexually and are consistent with a dispersed social neighbourhood and promiscuous mating system, with males ranging over significantly larger areas than females. No evidence was found for the spatial monopolisation of receptive females by dominant males. Although M. tanosi is an apparent habitat generalist, utilising a wide variety of sleeping sites and tree species in the littoral forests, population density is low. Results indicate that predator avoidance best explains the patterns governing sleep site selection and highlights the key role of Pandanacae species. This study demonstrates the importance of long-term population monitoring for nocturnal lemurs and highlights the critical relevance of local phenomena and forest management strategy for species conservation. Finally, this work provides several recommendations to counteract the observed decline in biodiversity in Sainte Luce

    A review of the Pteropus rufus (É. Geoffroy, 1803) colonies within the Tolagnaro region of southeast Madagascar – an assessment of neoteric threats and conservation condition

    Get PDF
    We surveyed 10 Pteropus rufus roost sites within the southeastern Anosy Region of Madagascar to provide an update on the areas’ known flying fox population and its conservation status. We report on two new colonies from Manambaro and Mandena and provide an account of the colonies first reported and last assessed in 2006. Currently only a solitary roost site receives any formal protection (Berenty) whereas further two colonies rely solely on taboo ‘fady’ for their security. We found that only two colonies now support an increased number of bats compared with a decade ago, whilst a further two colonies have been either displaced or disturbed and could no longer be found. A single colony appears to have declined significantly whereas a further three colonies appear to have remained static. In light of a decree that has imposed a specific hunting season for fruit bats, we hope that this census can provide a baseline for future population monitoring and contribute towards the assessment of the effectiveness of the legislation

    Morphological and ecological convergence at the lower size limit for vertebrates highlighted by five new miniaturised microhylid frog species from three different Madagascan genera

    Get PDF
    Miniaturised frogs form a fascinating but poorly understood amphibian ecomorph and have been exceptionally prone to taxonomic underestimation. The subfamily Cophylinae (family Microhylidae), endemic to Madagascar, has a particularly large diversity of miniaturised species which have historically been attributed to the single genus Stumpffia largely based on their small size. Recent phylogenetic work has revealed that several independent lineages of cophyline microhylids evolved towards highly miniaturised body sizes, achieving adult snout- vent lengths under 16 mm. Here, we describe five new species belonging to three clades that independently miniaturised and that are all genetically highly divergent from their relatives: (i) a new genus (Mini gen.nov.) with three new species from southern Madagascar, (ii) one species of Rhombophryne, and (iii) one species of Anodonthyla. Mini mum sp. nov. from Manombo in eastern Madagascar is one of the smallest frogs in the world, reaching an adult body size of 9.7 mm in males and 11.3 mm in females. Mini scule sp.nov. from Sainte Luce in southeastern Madagascar is slightly larger and has maxillary teeth. Mini ature sp.nov. from Andohahela in southeast Madagascar is larger than its congeners but is similar in build. Rhombophryne proportionalis sp.nov. from Tsaratanana in northern Madagascar is unique among Madagascar's miniaturised frogs in being a proportional dwarf, exhibiting far less advanced signs of paedomorphism than other species of similar size. Anodonthyla eximia sp.nov. from Ranomafana in eastern Madagascar is distinctly smaller than any of its congeners and is secondarily terrestrial, providing evidence that miniaturisation and terrestriality may be evolutionarily linked. The evolution of body size in Madagascar's microhylids has been more dynamic than previously understood, and future studies will hopefully shed light on the interplay between ecology and evolution of these remarkably diverse frogs

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Feasibility of preoperative chemotherapy for locally advanced, operable colon cancer: The pilot phase of a randomised controlled trial

    Get PDF
    Summary: Background Preoperative (neoadjuvant) chemotherapy and radiotherapy are more eff ective than similar postoperative treatment for oesophageal, gastric, and rectal cancers, perhaps because of more eff ective micrometastasis eradication and reduced risk of incomplete excision and tumour cell shedding during surgery. The FOxTROT trial aims to investigate the feasibility, safety, and effi cacy of preoperative chemotherapy for colon cancer. Methods In the pilot stage of this randomised controlled trial, 150 patients with radiologically staged locally advanced (T3 with ≄5 mm invasion beyond the muscularis propria or T4) tumours from 35 UK centres were randomly assigned (2:1) to preoperative (three cycles of OxMdG [oxaliplatin 85 mg/mÂČ, l-folinic acid 175 mg, fl uorouracil 400 mg/mÂČ bolus, then 2400 mg/mÂČ by 46 h infusion] repeated at 2-weekly intervals followed by surgery and a further nine cycles of OxMdG) or standard postoperative chemotherapy (12 cycles of OxMdG). Patients with KRAS wild-type tumours were randomly assigned (1:1) to receive panitumumab (6 mg/kg; every 2 weeks with the fi rst 6 weeks of chemotherapy) or not. Treatment allocation was through a central randomisation service using a minimised randomisation procedure including age, radiological T and N stage, site of tumour, and presence of defunctioning colostomy as stratifi cation variables. Primary outcome measures of the pilot phase were feasibility, safety, and tolerance of preoperative therapy, and accuracy of radiological staging. Analysis was by intention to treat. This trial is registered, number ISRCTN 87163246. Findings 96% (95 of 99) of patients started and 89% (85 of 95) completed preoperative chemotherapy with grade 3–4 gastrointestinal toxicity in 7% (seven of 94) of patients. All 99 tumours in the preoperative group were resected, with no signifi cant diff erences in postoperative morbidity between the preoperative and control groups: 14% (14 of 99) versus 12% (six of 51) had complications prolonging hospital stay (p=0·81). 98% (50 of 51) of postoperative chemotherapy patients had T3 or more advanced tumours confi rmed at post-resection pathology compared with 91% (90 of 99) of patients following preoperative chemotherapy (p=0·10). Preoperative therapy resulted in signifi cant downstaging of TNM5 compared with the postoperative group (p=0·04), including two pathological complete responses, apical node involvement (1% [one of 98] vs 20% [ten of 50], p<0·0001), resection margin involvement (4% [ four of 99] vs 20% [ten of 50], p=0·002), and blinded centrally scored tumour regression grading: 31% (29 of 94) vs 2% (one of 46) moderate or greater regression (p=0·0001). Interpretation Preoperative chemotherapy for radiologically staged, locally advanced operable primary colon cancer is feasible with acceptable toxicity and perioperative morbidity. Proceeding to the phase 3 trial, to establish whether the encouraging pathological responses seen with preoperative therapy translates into improved long-term oncological outcome, is appropriate

    Population dynamics of nocturnal lemurs in littoral forest fragments: The importance of long-term monitoring

    No full text
    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 summarise 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 285km of line transect and recorded 1,968 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 emphasise the importance of localised 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

    Supplementary material 6 from: Bellati A, Scherz MD, Megson S, Hyde Roberts S, Andreone F, Rosa GM, Noël J, Randrianirina JE, Fasola M, Glaw F, Crottini A (2018) Resurrection and re-description of Plethodontohyla laevis (Boettger, 1913) and transfer of Rhombophryne alluaudi (Mocquard, 1901) to the genus Plethodontohyla (Amphibia, Microhylidae, Cophylinae). Zoosystematics and Evolution 94(1): 109-135. https://doi.org/10.3897/zse.94.14698

    Get PDF
    The systematics of the cophyline microhylid frog genera Plethodontohyla and Rhombophryne have long been intertwined, and their relationships have only recently started to become clear. While Rhombophryne has received a lot of recent taxonomic attention, Plethodontohyla has been largely neglected. Our study is a showcase of just how complex the taxonomic situation between these two genera is, and the care that must be taken to resolve taxonomic conundrums where old material, multiple genus transitions, and misattribution of new material obfuscate the picture. We assessed the identity of the historic names Dyscophus alluaudi (currently in the genus Rhombophryne), Phrynocara laeve and Plethodontohyla laevis tsianovohensis (both synonyms of Rhombophryne alluaudi) based on an integrative taxonomic approach harnessing genetics, external morphology, osteological data obtained via micro-Computed Tomography (micro-CT) and bioacoustics. We show that (1) the holotype of Dyscophus alluaudi is a member of the genus Plethodontohyla; (2) the Rhombophryne specimens from central Madagascar currently assigned to Rhombophryne alluaudi have no affinity with that species, and are instead an undescribed species; and (3) Phrynocara laeve and Dyscophus alluaudi are not synonymous, but represent closely related species, whereas Plethodontohyla laevis tsianovohensis is tentatively confirmed as synonym of D. alluaudi. We resurrect and re-describe Plethodontohyla laevis, and re-allocate and re-describe Plethodontohyla alluaudi on the basis of new and historic material

    Resurrection and re-description of Plethodontohyla laevis (boettger, 1913) and transfer of Rhombophryne alluaudi (mocquard, 1901) to the genus Plethodontohyla (Amphibia, Microhylidae, Cophylinae)

    No full text
    The systematics of the cophyline microhylid frog genera Plethodontohyla and Rhombophryne have long been intertwined, and their relationships have only recently started to become clear. While Rhombophryne has received a lot of recent taxonomic attention, Plethodontohyla has been largely neglected. Our study is a showcase of just how complex the taxonomic situation between these two genera is, and the care that must be taken to resolve taxonomic conundrums where old material, multiple genus transitions, and misattribution of new material obfuscate the picture. We assessed the identity of the historic names Dyscophus alluaudi (currently in the genus Rhombophryne), Phrynocara laeve and Plethodontohyla laevis tsianovohensis (both synonyms of Rhombophryne alluaudi) based on an integrative taxonomic approach harnessing genetics, external morphology, osteological data obtained via micro-Computed Tomography (micro-CT) and bioacoustics. We show that (1) the holotype of Dyscophus alluaudi is a member of the genus Plethodontohyla; (2) the Rhombophryne specimens from central Madagascar currently assigned to Rhombophryne alluaudi have no affinity with that species, and are instead an undescribed species; and (3) Phrynocara laeve and Dyscophus alluaudi are not synonymous, but represent closely related species, whereas Plethodontohyla laevis tsianovohensis is tentatively confirmed as synonym of D. alluaudi. We resurrect and re-describe Plethodontohyla laevis, and re-allocate and re-describe Plethodontohyla alluaudi on the basis of new and historic material
    corecore