Browsing by Author "Menegon, Michele"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item The biological importance of the Eastern Arc Mountain of Tanzania and Kenya(2007-01) Burgess, Neil D.; Butynski, Thomas M.; Cordeiro, Norbert J.; Doggart, Nike; Fjeldså, Jon; Howell, Kim; Kilahama, Felician B.; Loader, Simon; Lovett, Jon C.; Mbilinyi, Boniface P.; Menegon, Michele; Moyer, David; Nashanda, Evarist; Perkin, Andrew; Rovero, Francesco; Stanley, William T.; Stuart, Simon N.The Eastern Arc Mountains are renown in Africa for high concentrations of endemic species of animals and plants. Thirteen separate mountain blocks comprise the Eastern Arc, supporting around 3300 km2 of sub-montane, montane and upper montane forest, less than 30% of the estimated original forested area. At least 96 vertebrate species are endemic, split as follows: 10 mammal, 19 bird, 29 reptile and 38 amphibian species. This includes four endemic or nearly endemic species of primate – the Sanje Mangabey, the Iringa Red Colobus, the Mountain Galago and the new Kipunji monkey that forms its own monotypic genus. A further 71 vertebrate species are near-endemic. At least 800 vascular plant species are endemic, almost 10% of these being trees. These endemics include the majority of the species of African violet – Saintpaulia, a well-known flowering plant in Western households. An additional 32 species of bryophytes are also endemic. Many hundreds of invertebrates are also likely to be endemic, with data for butterflies, millipedes and dragonflies indicating potential trends in importance. Seventy-one of the endemic or near-endemic vertebrates are threatened by extinction (8 critical, 27 endangered, 36 vulnerable), with an additional seven wide ranging threatened species. Hundreds of plant species are also threatened. Most Eastern Arc endemics are closed-forest specialists and comprise taxa with an ancient history and those of more recent origin, including some possessing ancient affinities with taxa from West Africa, Madagascar, and even South America and Southeast Asia. Mountain block prioritisation for biodiversity conservation shows that Udzungwas, East Usambaras and Ulugurus are the most important blocks, with other important blocks being the Ngurus and West Usambaras. Rankings are correlated closely with the area of remaining forest. Most of the remaining forest is found within nearly 150 Government Forest Reserves, with 106 of these managed nationally for water catchment, biodiversity and soil conservation and where forest exploitation is not allowed. Outside these areas most forest has been cleared, except in small village burial/sacred sites, a few Village Forest Reserves, and inaccessible areas. In most Eastern Arc Mountains the local populations have not encroached beyond the reserve boundaries to develop farms, but forest resources within the boundaries are used for fuel and building materials and some forests are heavily degraded. Fire is also a problem as it enters and destroys forests during the dry seasons. The future of the biodiversity on the Eastern Arc Mountains is closely tied to management policies and capacity of the Tanzania Forestry and Beekeeping Division, Tanzania National Parks Authority, and Kenya Forest Department. Supporting these agencies in their mandated job is an essential conservation investment over the longer term.Item A celebration of the works of John Charles Poynton(2013-05) Loader, Simon; Menegon, Michele; Howell, Kim; Müller, HendrikThe 15th meeting of the African Amphibian Working Group celebrated thecontributions of John Charles Poynton to African Herpetology. The meeting, inTrento, Italy, was timed to commemorate John’s 81st birthday (in May 2012), and hepresented a keynote speech that focused on a topic that has long fascinated him theAfrotemperate amphibian fauna. His presentation is published here, in a modifiedform, for this special issue of African Journal of Herpetology (Poynton 2013). Otherpapers on the main themes of John’s research are also included in this issue, whichinclude biogeography (Loader et al. 2013; Schreiner et al. 2013), taxonomy (Cruzet al. 2013) and morphology (Wilkinson et al. 2013)Item Description of A New and Critically Endangered Species of Atheris (Serpentes: Viperidae) From the Southern Highlands of Tanzania, With an Overview of The Country's Tree Viper Fauna(2011-12) Menegon, Michele; Davenport, Tim R. B.; Howell, KimA new species of arboreal forest viper (Serpentes: Viperidae: Atheris) from a forest fragment in the Southern Highlands of Tanzania is described and named Atheris matildae sp. nov. The species resembles the forest horned viper, Atheris cer-atophora Werner, by bearing horn-like supraciliary scales but it differs in size, body proportions, scalation, scale ultra-structure, and distribution. Genetic divergence is also assessed and the two species have an estimated divergence time of approximately 2.2 million years. An overview of the genus Atheris in Tanzania, including new distribution data, is pre-sented and the conservation status of the new taxon is discussedItem A New Dwarf Forest Toad (Amphibia: Bufonidae: Nectophrynoides) from the Ukaguru Mountains, Tanzania(2007) Menegon, Michele; Salvidio, Sebastiano; Ngalason, Wilirk; Loader, Simon P.A new species of Nectophrynoides from the Ukaguru Mountains, Eastern Arc Mountains Tanzania, is described. The new species is diagnosed by the presence of large prominent spines with keratinized tips, positioned on the dorsum, head and limbs. In addition, the combination of the following characters -presence of large tympanum and annulum, foot longer than tibia, the lack of parotoid glands and advertisement call features, allow this species to be distinguished from all other species in the genus. The new species adds to our understanding of the amphibian fauna of the Ukaguru Moun-tains, relatively undersampled and poorly understood.Item Persistence and stability of Eastern Afromontane forests: Evidence from brevicipitid frogs(2014-03) Loader, Simon; Ceccarelli, Fadia S.; Menegon, Michele; Howell, Kim; Kassahun, Roman; Mengistu, Abebe A.; Saber, Samy; Gebresenbet, Fikirte; de Sá, Rafael O.; Davenport, Tim R. B.; Larson, Joanna G.; Müller, Hendrik; Wilkinson, Mark; Gower, DavidAimThe persistence and stability of habitats through time are considered predictors of high levels of biodiversity in some environments. Long-term habitat persistence and stability may explain the species-rich, endemic forest fauna and flora of the Eastern Afromontane Biodiversity Region (EABR). Using complementary phylogenetic and biogeographical approaches, we examine evolutionary patterns in EABR brevicipitid frogs. Using these data, we test whether brevicipitid history reflects patterns of long-term forest persistence and/or stability across the EABR.LocationEast Africa.MethodsA dated phylogeny for brevicipitids was constructed using two nuclear and three mitochondrial markers. Alternative diversification models were used to determine signal for constant or varying net diversification rates. Using our dated tree, we identified areas of high phylogenetic diversity (PD), and inferred ancestral areas using likelihood and Bayesian approaches.ResultsBrevicipitids have a long history, with generic diversification among extant lineages pre-dating the Oligocene (> 33 Ma). Ancestral-area reconstructions indicate the presence of brevicipitids in the EABR since the Oligocene, and support a scenario of palaeoendemics surviving in EABR refugia. Ancestral-area reconstructions indicate that the central Eastern Arc Mountains (EAM) formed the initial centre of diversification of forest brevicipitids. Measures of PD show that diversity varies across the EABR but is highest in the EAM. Constant net diversification rate in brevicipitids is a significantly better fit than alternative, rate-variable models.Main conclusionsThe degree of persistence of forest habitats appears to be a contributing factor to the varying levels of diversity across the EABR in brevicipitids (and other organisms). In contrast to the Southern Highlands and Ethiopian Bale Mountains, the EAM stands out as an area that enabled the constant accumulation of brevicipitid species over a long period of time.Item Three New Species of Callulina (Amphibia: Anura: Brevicipitidae) Highlight Local Endemism and Conservation Plight of Africa's Eastern Arc Forests(Wiley, 2010) Loader, Simon P.; Gower, David; Ngalason, Wilirk; Menegon, MicheleAbstract Material ascribed to the genus Callulina from north-east Tanzania and south-east Kenya is assessed. Three new species of Callulina are described from the North (Callulina laphami sp. nov.) and South (Callulina shengena sp. nov. and Callulina stanleyi sp. nov.) Pare Mountains in Tanzania. The species are diagnosed based on morphological, acoustic, and molecular data. A new key to the species of Callulina is provided. Based on an interpretation of the International Union for Conservation of Nature (IUCN) red list, we suggest that the three species will qualify as critically endangered, because of their small distributions and the ongoing threat to their habitat. We reveal the high local endemism of Callulina in the northern part of the Eastern Arc Mountains, with each species restricted to no more than one mountain (fragment) block. This high local endemism in Callulina is probably widespread across the Eastern Arc, raising further conservation concern for this group of amphibians. Based on new molecular phylogenetic data for Callulina, we discuss biogeographical relationships among north-east Tanzanian mountains, and evolutionary patterns in Eastern Arc breviciptids.