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We conducted an analysis of deforestation and forest disturbance from 2005-2011 in Masoala National Park, the largest federal protected area in Madagascar. We found that the annual rate of forest change in 2010-2011 within the park (1.27%) was considerably higher than in 2005-2008 (0.99%), and was higher than the most recently published deforestation rate for all of Madagascar. Although deforestation and disturbance immediately following the 2009 coup d'état were lower than in the other time periods analyzed, the longer-term increase in forest change over the study period corroborates recent ground-based accounts of increased illegal activities in national parks, including logging of precious hardwoods. We also analyzed forest disturbance patterns in relation to rivers and travel distance from permanent villages. Forest disturbances were significantly closer to rivers than expected by chance, and 82% of disturbance was within the mean maximum travel distance to villages surrounding the park. Both results strongly indicate that most of the mapped disturbance in the study area is anthropogenic, despite two cyclones during the study period. High-resolution forest monitoring ensures that forest change statistics accurately reflect anthropogenic disturbances and are not inflated by forest losses resulting from natural processes.
The ecological responses of tropical forest wildlife to selective timber extraction have received considerable attention in the last few decades, yet there is little consensus among the large number of studies about the most appropriate sampling design. Here, we reviewed 26 years of tropical forest logging literature to evaluate the relationship between sampling design and the quality of information reported, which varied greatly among 75 studies. Most studies (88%) failed to include a pre-logging baseline condition in the sampling design, and the temporal scale of post-logging studies was generally inadequate. Studies also usually failed to report key information on study areas; only half of the articles reported some information on the spatial scale of the study, and only one-third presented some quantitative metric to describe forest habitat structure. Additionally, most studies (64%) failed to report the type of forest management and almost half (45%) did not describe the intensity of timber harvest in the logged areas. These sampling and reporting biases in logging studies hugely undermine the comparability among studies. We conclude with some general guidelines to maximize comparability among studies, and to enhance the potential usefulness of future logging studies for wildlife conservation strategies in tropical forest regions.
Biological invasions constitute a major threat to biodiversity. However, while the impact of invasive alien animals on native biota is often unambiguous, the impacts of invasive alien plants (IAP) appear to be considerably less severe and, at times, more debatable. Invasion by alien plants co-occur with other drivers of habitat change such that assessing impacts of IAP independently of these other factors may be difficult. Generalisations can be misleading, because studies reveal different responses of native plants to the presence of IAP. Therefore, there is a need to understand general trends and exceptions within a particular habitat. In the island of Mauritius, mechanical control of invasive alien plants has been implemented for decades in lowland wet forests. Weeded and non-weeded areas are very similar in all aspects, except for the control of IAP, providing an opportunity to study how IAP are affecting native plants. We monitored the reproductive output of 20-40 individuals each, of nine selected native species from different forest strata, in both weeded and adjacent non-weeded areas in a lowlan d wet forest, through direct count/estimation of the number of flower buds, flowers and fruits. Flower bud, flower and fruit production were greater in the weeded area. These results are consistent with previous findings that noted greater regeneration of native trees in these areas. This study also provides clues to reported decline of shade tolerant understory vegetation in alien invaded forest and further stresses the importance of removing alien plants to restore biodiversity and function and achieve conservation success.
Gaur, which became locally extinct before 1995 in Bandhavgarh Tiger Reserve (BTR), Central India, is an endangered animal per Schedule - I of the Indian Wildlife Protection Act (1972). A re-introduction program was therefore created to rebuild the gaur population in BTR, both to enhance the long-term survival of the species and to restore natural biodiversity. After re-introduction, the home range, habitat use and food habits of gaur (Bos gaurus gaurus) were studied in BTR, India, from January 2011 to January 2012. Nineteen gaurs (five males - three radio-collared and 14 females - nine radio-collared) were re-introduced from Kanha Tiger Reserve to Bandhavgarh Tiger Reserve in January 2011. The reintroduced gaurs were monitored periodically through ground tracking and satellite GPS fixes. The mean annual group size of gaur was estimated at 7.3 ± 0.76 (SE). The overall estimated summer, monsoon and winter home ranges of gaur were 290 km2, 137 km2 and 155 km2 (Minimum Convex Polygon) respectively. The overall individual male home ranges varied from 135 to 142 km2, and overall individual female home ranges varied from 32 to 169 km2. Radio collared locations were plotted on a classified (LISS III) habitat map of Bandhavgarh Tiger Reserve to evaluate the habitat use and availability in each season. Habitat preference was computed using Bonferroni confidence interval method, compositional analysis and Ivlev's index. In summer, gaur largely preferred grassland (P<0.0001), whereas in monsoon and winter, gaur preferred bamboo mixed forest (P<0.0001). Gaur avoi ded open mixed forest (P<0.0001) and agricultural land in all three seasons. Data on food habits were collected through opportunistic sightings. In total, gaur fed on 68 plant species. The present study has reported first-time information on ranging patterns of reintroduced gaur and their degree of preferences for different vegetation and terrain types across seasons, which will be very useful to the park administration for future conservation of this endangered species and for habitat intervention.
The main objective of this study was to analyze the relationship between population densities of the white-tailed deer Odocoileus virginianus and certain habitat and human characteristics in the tropical dry forest of the Tehuacan-Cuicatlan Biosph ere Reserve (TCBR), Mexico. To estimate population density and characterize the habitat, we established 32 strip transects (500 × 2 m) at four different locations in the TCBR from May to June during the dry season of 2010. Principal component analyses were used to order the 32 transects using habitat/human impact variables and tree species composition. Estimated average density was 1.7 deer/km2, ranging from 0.1 to 2.9 deer/km2. The variables associated with white-tailed deer density were: basal area, distance to roads, distance to the area with largest human population, slope, aspect and presence of cattle; the principal plant species were Zapotillo (Lantana camara), Chintoborrego (Vallesia glabra), Nanche (Bunchosia biocellata), Cuachalalate (Amphipterigyum adstringens) and Cuajiote Amarillo (Bursera aptera). Compared to other tropical dry forests, estimated white-tailed deer densities in the TCBR were lower. We discuss the possible effect of these variables on deer density and suggest management actions.
The continued existence of large carnivores such as the lion (Panthera leo Linnaeus, 1758) outside of protected areas is uncertain. Such populations are the least studied and the most rapidly declining. Mozambique contains roughly 8% of Africa's lions, nearly half of which persist outside of protected areas. We estimated the distribution and abundance of lions in an unprotected section of northwest Tete Province and identified potential threats to the local persistence of lion populations. Structured interviews of local people indicated lion presence and human-lion conflict. We used interview results and anthropogenic land uses defined via Google Earth to delineate lion range digitally. We estimated population size using two methods of density estimation. We estimate that 185 lions inhabit roughly two thirds of the study area, including a likely transfrontier population with Zambia. Lion populations are resident and possibly recovering. Proper management of limiting factors, such as human-wildlife conflict, may stimulate and sustain lion population growth in the study area.
This paper presents modeling approaches for wildlife conservation in a semi-arid savanna setting where there are frequent occurrences of drought. The model was used to test the extent to which wildlife income offers opportunities to reduce fluctuations in income as a result of variations in annual rainfall. For the application of the model the wildlife and agro-pastoral systems of southeastern Zimbabwe were simulated. Results show that wildlife income has the potential to compensate for some of the losses in expected income from livestock during droughts. However, wildlife income becomes second best to irrigated agriculture in stabilizing income in areas that show highly fluctuating rainfall. Possible reasons for this include high costs of exploiting the wildlife resource, and the small fraction of wildlife revenues received by households and communities. In order to search for sustainable solutions in areas such as the southeastern low veld of Zimbabwe, it is also important to be aware that the current human population and livestock densities are far above current sustainable levels. Our results therefore suggest that current and future efforts to conserve biodiversity are doomed to fail if there are no efforts made to decongest areas surrounding parks of high densities of human and herbivore populations, and to let local households earn more revenues from wildlife.
Despite the importance of sharks in structuring the marine food web, their biomass is declining dramatically throughout the world's oceans due to fishing pressures. Sharks caught as by-catch in long-line fisheries are sold for shark fins in the Asian fish market and secondarily as trunk sales for local consumption and fish meal. In order to determine the levels of heavy metals (mercury and lead) in oceanic shark populations in South Pacific waters, analyses of 39 Prionace glauca and 69 Isurus oxyrinchus were conducted. Mercury (Hg) and lead (Pb) were measured by cold vapor and via acetylene flame techniques, respectively. Mercury concentrations were similar in the studied sharks (p=0.1516), with 0.048 ± 0.03 µg·g−1 w/w for P. glauca and 0.034 ± 0.023 µg·g−1 w/w for I. oxyrinchus. P. glauca showed greater values of lead than I. oxyrinchus (p<0.001). Large specimens of both species showed high heavy metal concentration, while sexes showed no statistical differences (p>0.05). The metal concentrations reported in this work constitute a risk for human health, mainly from the high contributions of lead in tissues of P. glauca and I. oxyrinchus.
The Peruvian night monkey (Aotus miconax) is endemic to the eastern slopes of the Andes in northern Peru. We present preliminary behavioral data on A. miconax collected during 12 months of surveys on a single group living in a 1.4 ha forest fragment near the Centro Poblado La Esperanza, Amazonas Department. Follows were conducted for five nights each month around full moon. The group used 1.23 ha as their home range. Night ranges were between 0.16 and 0.63 ha. Activity budgets were 32 % feeding, 53 % travelling and 13 % resting. Average night path length was 823 m and average travel speed was 117 m/h. The study group has one of the smallest home ranges recorded for a night monkey group, probably the result of its isolated habitat. These results represent the first behavioral data on this species but results are limited by small sample sizes. A. miconax remains one of the least studied of all primates and is threatened by continued expansion of human populations and hunting.
Janet López-Saucedo, Julio Porfirio Ramón-Ugalde, José Jesús de Barroso-Padilla, Antonio Martin Gutiérrez-Gutiérrez, Reyna Fierro, Raul Eduardo Piña-Aguilar
The aoudad (Ammotragus lervia) is a wild ruminant considered the living ancestor of domestic sheep and goats. The original distribution of aoudads includes several countries in the North of Africa, but it has been introduced, for trophy-hunting purposes, into other countries (USA, Mexico and Spain). The species was declared vulnerable in the 2012 IUCN's Red List and is also included in the CITES II Appendix. Surprisingly, little is known about its conservation status or the reproductive biology of the natural populations. There are some reports of the application of basic assisted-reproduction techniques in captive aoudads. In this preliminary study, we explored the feasibility of implementing assisted reproduction procedures in captive aoudad females using non-traditional techniques for in vivo embryo production. This approach was used to obtain the best results using the minimum possible number of animals. Three aoudad females were synchronized using a domestic sheep protocol and subcutaneous osmotic pumps for the delivery of follicle-stimulating hormone. A mini-surgical approach combined with laparoscopy was performed to obtain in vivo-produced embryos. All females had an ovulatory response of more than three corporea lutea, but only five good quality morulae were obtained from one female. Those were cryopreserved by vitrification using a Cryotop®. In conclusion, our approach was successful in obtaining in vivo embryos using a limited number of females. Further studies are necessary to optimize the fertilization rate and clarify the effect of our protocol on embryo implantation and the production of offspring.
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