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Tropical small-holder farmers rely on sustainable food production. Crop seed predation by ants can cause substantial yield loss and result in high pesticide use., We conducted field experiments and questionnaire-based surveys aiming to assess the effect of sown-seed predation on four crop species ( Cucumis sativus, Daucus carota, Capsicum frutescens and Solanum melongena) in 15 vegetable gardens and the resulting impact on the net income of Indonesian farmers. Furthermore, we tested a commonly applied insecticide and herbicide for seed, seedling and plant protection aiming to understand their effect on ant seed predation., We found that the mean percentage of seeds removed per garden was 42.0%, 49.4%, 48.0% and 50.6% for C. sativus, D. carota, C. frutescens and S. melongena, respectively, halving the farmers' income after considering initial and operational costs. Insecticide and herbicide treatments did not affect seed predation success or overall ant abundance, although they had positive and negative effects on ant species-specific abundance., High overall ant abundance caused high seed predation rate in all gardens as a result of a functional redundancy of ant species, which compensated for pesticide-related species loss., Environmentally-friendly and more sustainable practices such as overseeding or seedling production in nurseries could substitute for these inefficient approaches of chemical pest control, although this requires further research. [ABSTRACT FROM AUTHOR]

Each year, numerous species thought to have disappeared are rediscovered. Yet, do these rediscoveries represent the return of viable populations or the delayed extinction of doomed species? We document the number, distribution and conservation status of rediscovered amphibian, bird, and mammal species globally. Over the past 122 years, at least 351 species have been rediscovered, most occurring in the tropics. These species, on average, were missing for 61 years before being rediscovered (range of 3-331 years). The number of rediscoveries per year increased over time and the majority of these rediscoveries represent first documentations since their original description. Most rediscovered species have restricted ranges and small populations, and 92% of amphibians, 86% of birds, and 86% of mammals are highly threatened, independent of how long they were missing or when they were rediscovered. Under the current trends of widespread habitat loss, particularly in the tropics, most rediscovered species remain on the brink of extinction. [ABSTRACT FROM AUTHOR]

Southeast Asia is a region of conservation concern due to heavy losses of its native habitats. In this overview, we highlight the conservation importance of Southeast Asia by comparing its degree of species endemism and endangerment, and its rate of deforestation with other tropical regions (i.e., Meso-America, South America, and Sub- Saharan Africa). Southeast Asia contains the highest mean proportion of country-endemic bird (9%) and mammal species (11%). This region also has the highest proportion of threatened vascular plant, reptile, bird, and mammal species. Furthermore, not only is Southeast Asia's annual deforestation rate the highest in the tropics, but it has also increased between the periods 1990-2000 and 2000-2005. This could result in projected losses of 13-85% of biodiversity in the region by 2100. Secondary habitat restoration, at least in certain countries, would allow for some amelioration of biodiversity loss and thus potentially lower the currently predicted extinction rates. Nonetheless, urgent conservation actions are needed. Conservation initiatives should include public education, sustaining livelihoods, and ways to enhance the sustainability of agriculture and increase the capacity of conservation institutions. Furthermore, these actions should be country-specific and not ignore areas heavily populated by humans, as they can also harbour high numbers of threatened species. We urge that cooperative conservation initiatives be undertaken and support (e.g., capacity-building) be given by more developed countries in the region and beyond. [ABSTRACT FROM AUTHOR]

All is not well for biodiversity in the tropics. Despite recent debate over the extent of future tropical extinctions and the effectiveness of reserve systems, the continued disappearance of habitat, soaring human population, and loss of vital ecosystem services demand immediate action. This crisis is worrying, given that tropical regions support over two-thirds of all known species and are populated by some of the world's poorest people, who have little recourse to lower environmental-impact lifestyles. Recent evidence has shown that in addition to unabated rates of forest loss coastal development, overexploitation of wildlife, catchment modification, and habitat conversion are threatening human well-being. We argue that the recent technical debate about likely extinctions masks the real issue that, to prevent further loss of irreplaceable tropical biodiversity, we must err on the side of caution. We need to avoid inadvertently supporting political agendas that assume low future extinction rates, because this will result in further destruction of tropical biodiversity. [ABSTRACT FROM AUTHOR]