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If current trends of declining fertility rates and increasing abandonment of rural land as a result of urbanization continue, this will signal a globally significant transformation with important consequences for policy makers interested in conservation planning. This transformation is presently evident in a number of countries and projections suggest it may occur in the future in many developing countries. We use rates of population growth and urbanization to project population trends in rural areas for 25 example countries. Our projections indicate a general decline in population density that has either occurred already (e.g., Mexico) or may occur in the future if current trends continue (e.g., Uganda). Using both temperate and tropical examples we present evidence that this process will lead to ecological homogenization as a dominant habitat (e.g., forest replaces a mosaic of human-maintained landscapes), resulting in declines in biodiversity at the local scale. Building on this information, we consider research programs that need to be conducted so that policy makers are prepared to effectively manage depopulated rural areas.
Tropical coastal wetlands have a rich biodiversity, a restricted geographic distribution and are a prime habitat for manatees in the regions where they occur in the Neotropics. Human pressures affect the persistence of tropical wetland ecosystems and hence of manatees. In the continental Neotropics, the West Indian manatee (Trichechus manatus) is represented in Mexico by the subspecies T. m. manatus. Lack of information regarding the current distribution of manatees in Mexico hampers conservation approaches of this marine mammal. In this paper we present information on a survey of a population of manatees found in the Catazajá wetlands (ca 60,000ha) in northeast Chiapas, Mexico. We additionally report on manatee conservation efforts spanning seven years aimed at involving the participation of local rural communities. Systematic surveys for the presence of manatees were conducted between Feb-Nov, 2007 by sightings along sampling transects in waterways, recording of manatee presence as evidenced by recently browsed aquatic vegetation, presence of stranded individuals and presence of deceased manatees. Additionally, some records of manatee presence underwater were obtained by using a side-scan sonar system. Lastly, interviews with 120 individuals from 10 local communities also yielded information on manatee presence in the wetland system. A map of the study area divided into a grid of 50 ha cells was used to plot and quantify the records of manatee presence obtained with the above procedures. Results indicated presence of manatees in 11% (ca 4,850 ha) of the 50 ha cells into which the study area was divided. Records indicate presence of manatees throughout the wetland, but with concentration in particular sectors. Involvement of local communities in manatee conservation has resulted in designating the Catazajá wetlands as a natural protected area.
KEYWORDS: co-management approaches, local communities, traditional institutions, ownership, centralized management, potentials, wildlife, Western Serengeti, Tanzania
Co-management arrangements are increasingly gaining popularity as an intervention to overcome the shortcomings of centralized management that impede harmonization of conflicting interests among the diverse stakeholder groups. The success of these arrangements depends, among other things, upon capitalizing on potentials existing in the area where they are intended to be implemented. This study was conducted in the western part of Serengeti National Park to analyze some potential for adopting the co-management approaches. We employed local communities' opinions, experience, knowledge, and attitudes to analyze these factors. The paper is framed around the premises that, among other things, co-management arrangements have the potential to work if: (i) the local communities have an outstanding level of awareness on the rationale of, and legal aspects pertaining to, wildlife conservation; (ii) the traditional institutions for management of natural resources exist and local communities have the ability to evaluate their performance, establish causes for inadequate performance and propose some workable solutions; (iii) local communities have the ability to evaluate different options for resource ownership and give valid reasons for opposing or supporting them. In conclusion we underscore the need for co-management approaches as an alternative intervention and a complement for current resource management approaches. We recommend promotion of local awareness on legal aspects of resource management, strengthening of traditional institutions for resource management and honoring people's choices of the types of resource ownership or rectifying the situations making them unpopular.
The Neotropics harbor between 30−50% of the world's herpetofauna. However, little is known about the ecology and natural history of many species, making conservation strategies difficult to plan. After reviewing published papers on world herpetofauna conservation, it was shown that conservation biology has a low impact factor in scientific journals in comparison with other related disciplines such as evolutionary biology and ecology. Moreover, herpetology has one of the lowest impact factors within the biological sciences journals. The number of publications on amphibian and reptile conservation has increased in recent years; however, only 31% of the papers on herpetofaunal conservation have been published in high impact journals. There are many challenges to overcome in the conservation of the Neotropical herpetofauna. Uniform and stable taxonomic nomenclature is critical to avoid overestimation of species richness and diversity for conservation assessments, and in the context of legal proceedings. Herpetofaunal research needs to be conducted within the appropriate socio-political and economic framework, in order to effectively implement conservation area networks. It is important to reevaluate the role of protected area systems in ensuring the persistence of communities and populations, and to identify strategies and future conservation priorities, based on climate-change scenarios. Population and community studies at different spatial and temporal scales are necessary to understand herpetofauna responses to anthropogenic disturbances, habitat loss and fragmentation, edge and matrix effects, and their synergy with micro-climatic gradients, emergent diseases and shifting patterns of genetic diversity. One of the biggest challenges for herpetofaunal conservation science in the neotropics is to control habitat loss and increase landscape connectivity along altitudinal gradients, while at the same time control species invasion that alter native species' interactions and spread emergent diseases (e.g. Chytridiomycosis) facilitated by climate change.
Rudolf von May, Alessandro Catenazzi, Ariadne Angulo, Jason L. Brown, Jorge Carrillo, Germán Chávez, Jesús H. Córdova, Aleyda Curo, Amanda Delgado, Marco A. Enciso, Roberto Gutiérrez, Edgar Lehr, Jorge L. Martínez, Margarita Medina-Müller, Alfonso Miranda, Daniel R. Neira, José A. Ochoa, Aarón J. Quiroz, Daniel A. Rodríguez, Lily O. Rodríguez, Antonio W. Salas, Tracie Seimon, Anton Seimon, Karen Siu-Ting, Juana Suárez, Claudia Torres, Evan Twomey
This study documents the current state of conservation knowledge on threatened amphibian species in Peru. Following the International Union for the Conservation of Nature (IUCN) classification system, we considered species in the following categories: Critically Endangered, Endangered, Vulnerable, and Near Threatened. Even though only the first three categories are regarded as threatened by IUCN, we included the fourth category to make comparisons with the list of threatened species issued by the Peruvian government. We used the Global Amphibian Assessment's database and the list issued in Peru for this comparison. We conducted separate field surveys in 17 regions of Peru to evaluate the presence/absence of threatened amphibian species and species that are potentially threatened. We also used the Declining Amphibian Database-DAPTF, to compare our results with previous assessments on population declines, and the World Wildlife Fund's Wildfinder database, to determine in which Neotropical ecoregion each species occurs. We compiled data on 83 species, 44 of which are recognized as threatened by the IUCN and/or the Peruvian government. The remaining 39 species should be re-assessed as they face various threats. A re-evaluation of current estimates is needed as only 8% of all species recorded in Peru are recognized as threatened by the government, whereas the global estimate of threatened species is about 32%. In addition to using IUCN criteria, this re-assessment should follow national guidelines standardized in Peru and be in accordance with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Because the habitat of almost 40% of threatened species reported herein still remains unprotected, and data on chytridiomycosis and other threats are lacking for most taxa, it is crucial to develop strategies for habitat conservation and research on disease dynamics in natural populations.
El bosque seco tropical es uno de los ecosistemas más amenazado del planeta y los reptiles que alberga han sido pobremente estudiados. En seis fragmentos de bosque seco tropical (con un área entre 7 y 84 ha) rodeados por potrero, se muestrearon reptiles durante el día y la noche, en tres temporadas a lo largo de 120 transectos lineales. Se encontró mayor riqueza de especies en los fragmentos de mayor área pero la relación “número de especies-área del fragmento” se perdió a medida que los estimadores de riqueza predijeron mayor número de especies en el ensamble. La abundancia total de reptiles y la composición de especies no varió en relación al área del fragmento pero el fragmento de mayor área presentó el mayor número de especies exclusivas. El mayor recambio de especies se dio entre los fragmentos grandes y los pequeños. El tamaño del fragmento claramente afectó a Anolis vittigerus, lagarto que hasta el momento no se encuentra incluido en las categorías de riesgo de la UICN. Más del 70% de las especies encontradas son raras (abundancia < a 4 individuos) por lo cual es necesario realizar estudios poblacionales intensivos para poder conocer la respuesta de las especies crípticas a la pérdida y fragmentación del hábitat.
Tropical amphibians face a severe decline crisis with ca. 35% of species being currently threatened in the Neotropics. We selected 16 endangered-hylid species and used species records to model their potential geographical distribution for the continental Neotropics. We found that there is a strong influence of slope in hylid geographical distribution that interacts synergistically with maximum rainfall and temperature changes over the year. We identified some intersecting areas of species overprediction along southern Neotropics, which could be important for future biological surveys searching for undescribed microendemic hylid species. Nine of the 16 studied hylids have small geographic ranges with only 25% of its potential distribution being currently protected in the Neotropics. The remaining seven species are still in need of additional conservation areas to ensure the protection of at least 25% of its original distribution range in Mesoamerica. Most Neotropical endangered hylids have only the periphery of their distribution protected with its core distribution outside protected areas. These species may be especially threatened because they now occur in small, isolated subpopulations due to habitat fragmentation and loss. We suggest that conservation efforts for Neotropical hylids should be focused on restricted-range species and in the establishment of additional conservation area networks in Mesoamerica. Remaining habitats for threatened hylids need to be managed as a coordinate network including site-scale and landscape-scale actions to buffer the extinction-driven process caused by inbreeding, genetic drift, and demographic stochasticity.
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