Time filter

Source Type

Due to anthropogenic pressures, the chameleons of the dry deciduous forests in Northern Madagascar are rapidly losing their habitat. This study uses an already tried and tested methodology, based upon distance sampling, to monitor chameleon populations in three forest fragments between Montagne d'Ambre Parc National and Ankarana Réserve Spéciale. In total, 190 chameleons comprised of four species: Brookesia stumpffi, Furcifer oustaleti, Furcifer pardalis, Furcifer petteri were recorded during the study. Recorded at the highest pooled density was B. stumpffi (149.82 ha-1), followed by F.pardalis (70.48 ha-1), F. petteri (65.56 ha-1), and F.oustaleti (54.12 ha-1). Both F. pardalis and F. oustaleti were absent from one of the forest fragments. All densities were estimated using the computer program DISTANCE. Disturbance surveys in each forest revealed a variety of levels of human disturbances which may well be impacting the chameleon populations. The forest fragments between Montagne d'Ambre Parc National and Ankarana Réserve Spéciale are currently unprotected and may well be home to some of the last vestiges of now isolated chameleon populations. Without further in depth information, such as those provided by this study, successful conservation management strategies for the future will be difficult. Source

Platts P.J.,University of York | Ahrends A.,Royal Botanic Garden Edinburgh | Gereau R.E.,Missouri Botanical Garden | McClean C.J.,University of York | And 6 more authors.
Diversity and Distributions | Year: 2010

Aim: Data shortages mean that conservation priorities can be highly sensitive to historical patterns of exploration. Here, we investigate the potential of regionally focussed species distribution models to elucidate fine-scale patterns of richness, rarity and endemism. Location: Eastern Arc Mountains, Tanzania and Kenya. Methods: Generalized additive models and land cover data are used to estimate the distributions of 452 forest plant taxa (trees, lianas, shrubs and herbs). Presence records from a newly compiled database are regressed against environmental variables in a stepwise multimodel. Estimates of occurrence in forest patches are collated across target groups and analysed alongside inventory-based estimates of conservation priority. Results: Predicted richness is higher than observed richness, with the biggest disparities in regions that have had the least research. North Pare and Nguu in particular are predicted to be more important than the inventory data suggest. Environmental conditions in parts of Nguru could support as many range-restricted and endemic taxa as Uluguru, although realized niches are subject to unknown colonization histories. Concentrations of rare plants are especially high in the Usambaras, a pattern mediated in models by moisture indices, whilst overall richness is better explained by temperature gradients. Tree data dominate the botanical inventory; we find that priorities based on other growth forms might favour the mountains in a different order. Main conclusions: Distribution models can provide conservation planning with high-resolution estimates of richness in well-researched areas, and predictive estimates of conservation importance elsewhere. Spatial and taxonomic biases in the data are essential considerations, as is the spatial scale used for models. We caution that predictive estimates are most uncertain for the species of highest conservation concern, and advocate using models and targeted field assessments iteratively to refine our understanding of which areas should be prioritised for conservation. © 2010 Blackwell Publishing Ltd. Source

Labanowski R.J.,Society for Environmental Exploration Frontier | Lowin A.J.,Society for Environmental Exploration Frontier
Herpetology Notes | Year: 2011

A small area within a fragment of unprotected secondary dry deciduous forest named Antsolipa, located between the protected areas of Montagne d'Ambre National Park and Ankarana Special Reserve in northern Madagascar, was surveyed for its reptile fauna over a ten-week period between July and September 2009, during the dry season. A combination of active searching, opportunistic collection as well as pitfall and funnel trapping yielded a total of 19 reptile species including 2 listed as vulnerable on the IUCN Red List of Threatened Species and 7 species on the CITES appendices. As this forest was previously unstudied, this survey provides the first inventory of reptile species for the area, also providing a new locality record for a little known species of colubrid snake, Pararhadinaea melanogaster, of which only six specimens were previously known from a few locations in Northern Madagascar. It is also the first locality where multiple specimens of this species have been observed. The discovery of a skink thought to be Amphiglossus tanysoma is also important, as this would be a northern range extension for this species. The fragmented forests in this area are under increasing threat from logging and clearing, and as few studies have been carried out in these unprotected areas their conservational importance remains poorly known. It is hoped that the results of this survey may help to highlight the rich species diversity contained within these forests, and hopefully lead to some form of official protection of what little remains of these potentially important habitats. Source

Discover hidden collaborations