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March 2013 | Vol. 6 | Issue 1 | p 1-157
Thomas F. Allnutt, Gregory P. Asner, Christopher D. Golden and George V. N. Powell Since the onset of a political crisis in 2009, there have been widespread and increasing reports of illegal activities in Madagascar’s national parks, including deforestation, logging of precious hardwoods, mining, and poaching of endangered species. From 2008 to 2009, for example, trade records show that exports of rosewood (Dalbergia spp.) from Madagascar to China, the world’s largest consumer of Malagasy hardwoods, nearly tripled. This increase is generally attributed to illegal logging in Masoala and Marojejy protected areas in northeastern Madagascar following a transfer of presidential power in March 2009, which has been widely characterized as a “coup d’état”. Despite the attention this issue has received in the press, since the coup there have been few attempts to quantify the rate and magnitude of these changes in Madagascar's national parks. This is due to the fact that these areas are often extremely remote, and many of the changes to the forest are too small to be detected by traditional remote sensing methods. In this study we demonstrate new methods for mapping deforestation and small-scale forest disturbance in Masoala national park. We find the rate of forest change in 2010-2011 within the study area (1.27%) to be higher than the most recently published annual deforestation rate for all of Madagascar. This result is particularly alarming given that Masoala has the highest level of legal forest protection in Madagascar, and highlights an important and persistent problem within Madagascar’s largest national park. Assessing sampling biases in logging impact studies in tropical forests | pages 16-34 Juliana Laufer, Fernanda Michalski and Carlos A. Peres The burgeoning global demand for timber products over the past three decades has resulted in rapid escalation in the spatial extent and intensity of the logging industry in tropical forests. Selective logging has been considered one of the least detrimental modes of anthropogenic disturbance to animal and plant communities, and much of the tropical forest conservation literature has focused on logging disturbance. Yet, there is little agreement about the impacts of selective logging on tropical wildlife communities. Although many studies have evaluated the impacts of selective logging on tropical forest fauna, these are plagued by inconsistencies in sampling methods and the poor quality of results reported, which render the comparability of different studies difficult, if not impossible. Here, we address this issue by evaluating methodological differences in 75 logging impact studies published in the last 26 years. The quality of information reported varied greatly among studies, and most of them failed to include baseline information on the study area prior to the onset of selective logging activities. The stand recovery time in the aftermath of logging was also generally inadequate. We highlight that some information (e.g. forest management type, intensity of timber extraction, detailed description and size of the study area) are essential for appropriate interpretation of the results obtained. We conclude by providing some general guidelines to enhance the comparability among future logging studies, and their potential usefulness for wildlife conservation strategies in tropical forest regions. Invasive alien plants elicit reduced production of flowers and fruits in various native forest species on the tropical island of Mauritius (Mascarenes, Indian Ocean) | pages 35-49 M.L. Fabiola Monty, F.B. Vincent Florens and Cláudia Baider Invasive alien species poses a major threat to the conservation of biodiversity. While the impacts of invasive animals, such as predators, are often rapid and unambiguous, those of invasive alien plants are more debatable. A major reason is the difficulty of isolating these impacts from other threats, with which they co-occur (e.g. harvesting or the fragmentation of habitats). Furthermore, several studies revealed contrasting responses of native species in the presence of invasive plants calling for a clearer understanding of alien plants’ impacts. On Mauritius, an oceanic island in the south-western Indian Ocean, mechanical control of invasive alien plants, where they are cut and uprooted, has been implemented for decades on representative patches of native forests. This situation of weeded areas located next to similar adjacent non-weeded areas provides an opportunity to study how invasive alien plants affect native plants. Here we compared the reproductive output of selected native tree species of different sizes in weeded and non-weeded areas. Native species in the weeded area had greater flower bud, flower and fruit production. These results are consistent with previous studies that found better regeneration of native species in weeded areas. The study indicates that invasive plants have direct negative impacts on native species, and that the mere control of invasive plants can be an effective solution. These results also have implications for the conservation of fauna, particularly pollinators or frugivores, for which flowers and fruits constitute vital resources. Home range, habitat use and food habits of re-introduced gaur (Bos gaurus gaurus) in Bandhavgarh Tiger Reserve, Central India | pages 50-69 K. Sankar, H. S. Pabla, C. K. Patil, Parag Nigam, Qamar Qureshi, B. Navaneethan, Manas Manjreakar, Preeti S. Virkar and Krishnendu Mondal The last small population of gaur (32 individuals) migrated out of the Bandhavgarh Tiger Reserve (BTR), India in 1995 and hence it was decided to reintroduce gaur in BTR as it would be a major conservation initiative for this Endangered Species. Nineteen gaur (14 females, 05 males) were captured from Kanha Tiger Reserve and translocated to BTR. Of these, 12 animals were fitted with radio collars. These animals were transported by road for about 250 km in a special truck fabricated for such purposes. Initially the gaurs were kept in a 50 hectare enclosure in BTR so as to get them acclimatized to the surroundings and after one month they were released in to wild. After re-introduction, the home range, habitat use and food habits of gaur were studied in BTR from January 2011 to January 2012. Gaur initially explored large areas of 290 km2 after their reintroduction and subsequently their ranges reduced to 160 km2 after exploration of new areas. In summer they preferred grassland, in monsoon and winter preferred bamboo mixed forest and avoided open mixed forest and agricultural land in all seasons. The outcome of the study will be useful to the park administration for future conservation of this species and for habitat intervention. The protocol prepared for gaur capture, chemical immobilization and transportation will be highly useful for managers and conservationists in planning and execution of similar reintroduction program of mega-herbivores in their entire distributional range. Habitat and human factors associated with white-tailed deer density in the tropical dry forest of Tehuacan-Cuicatlan Biosphere Reserve, Mexico | pages 70-86 Michelle Ramos-Robles, Sonia Gallina and Salvador Mandujano La Reserva de la Biosfera de Tehuacán-Cuicatlán (RBTC) con 4,906 km2 en los estados de Puebla y Oaxaca, constituye una muestra excepcional de los ecosistemas semiáridos del trópico mexicano debido a su alta diversidad biológica, geológica, cultural y de endemismos. Por ejemplo, contiene cerca del 10% de la flora de México y más de 400 especies de vertebrados. En la RBTC habitan tres ungulados silvestres: pecarí de collar (Pecari tajacu), temazate rojo (Mazama temama) y venado cola blanca (Odocoileus virginianus). Similar a otras regiones del país, en la RBTC estos ungulados son ampliamente aprovechados por las comunidades para complementar el consumo de proteína animal y recreación. Además, el aprovechamiento de estas especies, principalmente del venado cola blanca, ha aumentado notablemente en las Unidades para la Conservación y Uso Sustentable de la Vida Silvestre conocidas como UMAs. En este estudio, Ramos-Robles y colaboradores analizan la relación entre la densidad del venado cola blanca y algunas características del hábitat y factores humanos asociados. Encontraron que las principales variables fueron el área basal, la distancia a caminos, la distancia a la localidad con mayor número de habitantes, la orientación y la presencia de ganado. Además, en las localidades con mayor densidad de venados las plantas dominantes fueron Zapotillo (Lantana camara) Chintoborrego (Vallesia glabra), Nanche (Bunchosia biocellata) Cuachalalate (Amphipterigyum adstringens) y Cuajiote Amarillo (Bursera aptera). En el trabajo discuten el posible efecto de estas variables sobre la densidad del venado y sugieren algunas acciones de manejo. Distribution and abundance of lions in northwest Tete Province, Mozambique | pages 87-107 Andrew P. Jacobson, Megan E. Cattau, Jason S. Riggio, Lisanne S. Petracca and Derek A. Fedak The persistence of wide-ranging carnivores, including the African lion (Panthera leo), remains uncertain as anthropogenic impacts continue to increase across the globe. Lion populations are declining throughout Africa and particularly rapidly in locations outside protected areas. Lions outside protected areas are also the least known and subject to the gravest threats such as poaching. As this uncertainty outside protected areas hinders effective conservation initiatives, monitoring of these lion populations is critical. Mozambique contains nearly 10% of Africa’s lions, and roughly half of these reside outside protected areas. We estimated the distribution and abundance of lions and identified potential threats to lion populations in an unprotected section of northwest Tete Province, Mozambique. Much of this area is included in a revenue-sharing agreement on regional ecotourism ventures. Furthermore, the study area borders Zambia and is close to significant lion populations in two Zambian national parks. We determined lion distribution from information gathered from over 60 interviews with local people about wildlife presence. We then refined this distribution by excluding areas that were heavily impacted by people, as identified by investigating Google Earth imagery. We estimate lion range covers roughly two thirds of the study area, and likely crosses the border with Zambia. Using density values from nearby regions, we estimate roughly 185 lions. The population may be rebounding from earlier persecution although it is under threat from habitat loss, poaching, and trophy hunting Wildlife as insurance against rainfall fluctuations in a semi-arid savanna setting of southeastern Zimbabwe | pages 108-125 X. Poshiwa, R.A. Groeneveld, I. M.A. Heitkönig, H.H.T. Prins and E. C. van Ierland In sub-Saharan Africa, there are frequent occurrences of drought. However, there is an assertion that wildlife can cushion local people against income fluctuations due to drought. In order to test that assertion, we simulated the wildlife and agro-pastoral systems of southeastern Zimbabwe and test the extent to which wildlife income offers opportunities to reduce fluctuations in household income as a result of variations in annual rainfall. Results showed that after suffering eight years of consecutive droughts, local people lose so much that the lowest income becomes negative. The situation only improves with addition of wildlife plots that result in lowest income increasing with addition of wildlife. Model results were also affected by the profitability of irrigated agriculture, where irrigated agriculture prevented the income to be negative. Results therefore suggested that wildlife income provides local people with insurance against rainfall fluctuations when local people do not engage in irrigated agriculture. We concluded that wildlife income may improve the livelihoods of people living around them particularly their ability to cope with drought risk depending on the profitability of irrigated agriculture. This study provide evidence to policy makers that rainfall variability is one of the strongest justification for adopting wildlife and other natural resource-based land uses as an alternative and sustainable strategy for social and economic betterment. Heavy metal concentrations of two highly migratory sharks (Prionace glauca and Isurus oxyrinchus) in the southeastern Pacific waters: comments on public health and conservation | pages 126-137 Sebastián A. Lopez, Nicole L. Abarca and Roberto Meléndez C. Sharks are very important for the world and also for us. Because in the nature they provide the balance in the oceans, mainly by their top predator characteristic, and the world would not as we know it today if they did not exist. Also the humans eating this fishes in different ways either as fish meat or fins principally like soup or indirectly as fishmeal presents in different type of foods. Actually, the scientific’s are worrying by the heavy metals levels presents in the food. So, in order to determine the levels of mercury and lead we analysed 39 blue sharks and 69 mako short fin shark in the south Pacific waters. We found high levels of lead and low concentrations for mercury, however is highly toxic for humans when both metals are combined by the synergistic effect. So we concluded that the concentration find in this study constitute a risk for human health.
Sam Shanee, Nestor Allgas and Noga Shanee Night monkeys are the only nocturnal monkey species in the Americas. They are small animals, with adults weighing only about 1 kg. They live in small family groups of up to seven individuals. The Peruvian night monkey (Aotus miconax) is one of the least known and rarest of all primates. It is only found in the cloud forests of northern Peru at altitudes between 1200 and 3100 meters above sea level and has never been studied in the wild. We followed a group of Peruvian night monkeys for 12 months observing their behaviour and diet. The group lived in a small isolated patch of cloud forest. The study group showed generally similar behaviours and diet to other species of night monkeys. Although our study group spent a lot more time foraging than most other species, this could be because they need more food to get enough energy to keep warm in the colder climate at high altitudes. The group also showed adaptations to living in their heavily altered environment. The fact that this species is able to survive in fragmented areas gives hope for their conservation in an area with one of the highest deforestation rates in Peru. We are continuing our studies on this species combined with conservation work protecting the remaining forests, forest fragments and connectivity for the survival of this species. Superovulation, in vivo embryo recovery and cryopreservation for Aoudad (Ammotragus lervia) females using osmotic pumps and vitrification: a preliminary experience and its implications for conservation | pages 149-157 Janet López–Saucedo, Julio Porfirio Ramón-Ugalde, José de Jesús Barroso-Padilla, Antonio Martin Gutiérrez-Gutiérrez, Reyna Fierro and Raul Eduardo Piña-Aguilar The aoudad (Ammotragus lervia) is a wild ruminant considerer the ancestor of domestic sheep and goat. It lives in the North of Africa; but it has introduced with hunting purposes in USA, México and Spain. Its conservation status is declared as vulnerable and little is known about the welfare or reproduction of the natural populations in Africa. In this initial experiment, we explored obtaining and freezing embryos of aoudads captive at Leon’s Zoological Park in Mexico, using non-traditional techniques to producing embryos, with the goal of get the best results using the less possible number of animals. The reproductive cycle of three females was synchronized using a protocol designed for domestic sheep and were employed micro-pumps located under the skin for delivering follicle stimulating hormone −which is the hormone inducer of egg production. Later, it was performed a mini-surgery to obtain the embryos developed inside the females. All females had a good response to hormone and five embryos were obtained. These embryos were freeze by the vitrification technique (named because there is not ice-crystal formation during embryo freezing) using a device called Cryotop®. This is the first experiment that successfully obtains and freezes aoudad embryos. There are required future studies to determine how works this protocol on pregnancies and offspring production. The use of this type of assisted reproduction techniques cans maintain healthy and numerous the African aoudads in captivity with the goal of future re-introduction in their natural habitat. Reader comments are generally moderated. If you find something inappropriate, please contact Tropical Conservation Science. The opinions expressed in reader comments are those of the author only, and do not necessarily reflect the opinions of other authors or Tropical Conservation Science. |
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Tropical Conservation Science is an open-access e-journal that publishes research relating to conservation of tropical forests and other tropical ecosystems.
Volume 6: Issue 1 Table of Contents All issues Mar 2008 Jun 2008 Sep 2008 Dec 2008 Mar 2009 Jun 2009 Sep 2009 Dec 2009 Mar 2010 Jun 2010 Sep 2010 Dec 2010 Mar 2011 Jun 2011 Sep 2011 Dec 2011 Mar 2012 Jun 2012 Sep 2012 Dec 2012 Mar 2013 Jun 2013 Aug 2013 Sep 2013 Nov 2013 Dec 2013 Mar 2014 Jun 2014 Sep 2014 Dec 2014 Mar 2015 Jun 2015 Sep 2015 Dec 2015 Mar 2016 Jun 2016 Most downloaded 2008 2009 2010 2011 2012 All time ADVERTISEMENT SEARCH  This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. |
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