Deem S.L.,Institute for Conservation Medicine |
Porton I.J.,Madagascar Fauna and Flora Group
Journal of Virology | Year: 2015
The roles of host genetics versus exposure and contact frequency in driving cross-species transmission remain the subject of debate. Here, we used a multitaxon lemur collection at the Saint Louis Zoo in the United States as a model to gain insight into viral transmission in a setting of high interspecies contact. Lemurs are a diverse and understudied group of primates that are highly endangered. The speciation of lemurs, which are endemic to the island of Madagascar, occurred in geographic isolation apart from that of continental African primates. Although evidence of endogenized viruses in lemur genomes exists, no exogenous viruses of lemurs have been described to date. Here we identified two novel picornaviruses in fecal specimens of ring-tailed lemurs (Lemur catta) and black-and-white ruffed lemurs (Varecia variegata). We found that the viruses were transmitted in a species-specific manner (lesavirus 1 was detected only in ring-tailed lemurs, while lesavirus 2 was detected only in black-andwhite ruffed lemurs). Longitudinal sampling over a 1-year interval demonstrated ongoing infection in the collection. This was supported by evidence of viral clearance in some animals and new infections in previously uninfected animals, including a set of newly born triplets that acquired the infection. While the two virus strains were found to be cocirculating in a mixed-species exhibit of ring-tailed lemurs, black-and-white ruffed lemurs, and black lemurs, there was no evidence of cross-species transmission. This suggests that despite high-intensity contact, host species barriers can prevent cross-species transmissions of these viruses. © 2015, American Society for Microbiology.
Ghulam A.,Saint Louis University |
Porton I.,Saint Louis Zoo |
Porton I.,Madagascar Fauna and Flora Group |
Freeman K.,Madagascar Fauna and Flora Group
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2014
In this paper, we propose a decision tree algorithm to characterize spatial extent and spectral features of invasive plant species (i.e., guava, Madagascar cardamom, and Molucca raspberry) in tropical rainforests by integrating datasets from passive and active remote sensing sensors. The decision tree algorithm is based on a number of input variables including matching score and infeasibility images from Mixture Tuned Matched Filtering (MTMF), land-cover maps, tree height information derived from high resolution stereo imagery, polarimetric feature images, Radar Forest Degradation Index (RFDI), polarimetric and InSAR coherence and phase difference images. Spatial distributions of the study organisms are mapped using pixel-based Winner-Takes-All (WTA) algorithm, object oriented feature extraction, spectral unmixing, and compared with the newly developed decision tree approach. Our results show that the InSAR phase difference and PolInSAR HH-VV coherence images of L-band PALSAR data are the most important variables following the MTMF outputs in mapping subcanopy invasive plant species in tropical rainforest. We also show that the three types of invasive plants alone occupy about 17.6% of the Betampona Nature Reserve (BNR) while mixed forest, shrubland and grassland areas are summed to 11.9% of the reserve. This work presents the first systematic attempt to evaluate forest degradation, habitat quality and invasive plant statistics in the BNR, and provides significant insights as to management strategies for the control of invasive plants and conversation in the reserve. © 2013 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
Moore M.,Madagascar Fauna and Flora Group |
Niaina Fidy J.F.S.,Madagascar Fauna and Flora Group |
Edmonds D.,Association Mitsinjo
Tropical Conservation Science | Year: 2015
In March 2014, the Asian toad Duttaphrynus melanostictus was reported from Madagascar’s second largest city and main port Toamasina, raising immediate concerns about the invasive nature of the newly introduced toad and its environmental impact should it spread throughout the island. As part of a study on the feasibility of eradication, we conducted 516 interviews and 120 visual encounter surveys between April and November 2014. We found the toad to be widespre ad to the south and west of city center and estimate its minimum range to include an area of at least 108 km 2 . Social surveys indicate that the toad may have already been present for some years and potentially introduced prior to 2010, with the site of its introduction likely south of Toamasina near National Route 2 and the Ambatovy Plant. We discuss limitations of our survey methodology, proposed improvements for future work, and the implications of our results on eradication and control measures. © Maya Moore, Jean Francois Solofo Niaina Fidy and Devin Edmonds.
Ghulam A.,Saint Louis University |
Ghulam O.,Chongqing University |
Maimaitijiang M.,Saint Louis University |
Maimaitijiang M.,Xinjiang Agricultural University |
And 3 more authors.
Remote Sensing | Year: 2015
In this paper, grid cell based spatial statistics were used to quantify the drivers of land-cover and land-use change (LCLUC) and habitat degradation in a tropical rainforest in Madagascar. First, a spectral database of various land-cover and land-use information was compiled using multi-year field campaign data and photointerpretation of satellite images. Next, residential areas were extracted from IKONOS-2 and GeoEye-1 images using object oriented feature extraction (OBIA). Then, Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) data were used to generate land-cover and land-use maps from 1990 to 2011, and LCLUC maps were developed with decadal intervals and converted to 100 m vector grid cells. Finally, the causal associations between LCLUC were quantified using ordinary least square regression analysis and Moran's I, and a forest disturbance index derived from the time series Landsat data were used to further confirm LCLUC drivers. The results showed that (1) local spatial statistical approaches were most effective at quantifying the drivers of LCLUC, and (2) the combined threats of habitat degradation in and around the reserve and increasing encroachment of invasive plant species lead to the expansion of shrubland and mixed forest within the former primary forest, which was echoed by the forest disturbance index derived from the Landsat data. © 2015 by the authors.
Freeman K.L.M.,Madagascar Fauna and Flora Group |
Bollen A.,Madagascar Fauna and Flora Group |
Solofoniaina F.J.F.,Madagascar Fauna and Flora Group |
Andriamiarinoro H.,Missouri Botanical Garden |
And 2 more authors.
Plant Biosystems | Year: 2014
Using the example of Madagascar Fauna and Flora Group (MFG), we look at the factors which contribute to the successful maintenance of an international consortium dedicated to the conservation of Malagasy biodiversity. We discuss the philosophy, mission and set-up of the MFG and how, over its 25-year history, it has enabled the productive collaboration of its diverse international members to achieve the common goal of helping to protect Madagascar's unique biodiversity. We explore the benefits of pooling resources to fund a stable base of personnel and infrastructure to maximise the conservation impact of contributions from organisations that might not otherwise be able to fund viable independent programmes and consider the benefits that accrue to partners in the consortium. We highlight specific examples of plant conservation projects set up as a result of the productive working relationship between MFG and Missouri Botanical Garden to reinforce the argument that like-minded organisations working in successful partnership can far exceed the conservation capacity of individual institutions. © 2014 Società Botanica Italiana.