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Tapirus terrestris populations are declining due to habitat loss and hunting. Our objective is to estimate the minimum viable population size for tapirs in the Atlantic Forest. A Population Viability Analysis was conducted using VORTEX. Demographic parameters were based on data published in the scientific literature. Demographically and genetically viable populations should have more than 30 and 200 individuals, respectively. Sensitivity analysis suggests that mortality rate, sex ratio and inbreeding depression are important for population persistence. Preserving tapir populations is important to avoid local extinction, preserve intra-specific diversity, maintain evolutionary potential and ensure tapirs play their ecological roles within ecosystems. [ABSTRACT FROM AUTHOR]

A population viability analysis (PVA) using the computer package VORTEX was conducted to assess the minimum viable population (MVP) of the Atlantic Forest endemic marsupial Micoureus paraguayanus. The objectives were: to estimate demographic and genetic MVPs that could be used as quasi-extinction thresholds for future modeling, to estimate the minimum area of suitable habitat (MASH), and to use these results to apply IUCN red list criteria so as to suggest its proper status classification. The model predicted that populations of 100 and 2000 individuals were necessary to achieve demographic and genetic stability, respectively, within a time frame of 100 years. The model was sensitive to changes in inbreeding depression, mortality and reproduction. MASH estimated to contain genetically viable populations reached 1300 ha. Fortunately, there still are quite a number of forest remnants equal to or larger than this. Isolation is suggested as the principal threat facing M. paraguayanus. Therefore, promoting conditions for dispersal together with efforts dealing with translocation, should prove to be the most appropriate management strategies for M. paraguayanus at this stage. A landscape pattern composed of large patches holding MVPs and sets of smaller patches harboring viable metapopulations that maximize probability of dispersal can provide a viable scenario for the conservation of M. paraguayanus. [ABSTRACT FROM AUTHOR]

A population viability analysis (PVA) was conducted to assess the minimum viable population (MVP) of the Atlantic Forest spiny rat Trinomys eliasi, a species threatened by habitat loss and restricted geographical distribution. Objectives were to suggest quasi-extinction thresholds, estimate minimum areas of suitable habitat (MASH) and MVPs, and compare results with the species’ current status. The computer package VORTEX was used. The model predicted sizes of 200 animals to achieve demographic stability, but buffering declines in genetic variability required populations of 2000 animals. Estimated MASHs were approximately 250 and 2500 ha for demographic and genetic stability, respectively. Mortality rate and mean litter size were the most sensitive parameters to changes in model assumptions. The protection of known populations and the search for extant populations are the first steps in conservation. T. eliasi''s issue could help protecting the coastal shrubland ecosystem of Rio de Janeiro state. Observing IUCN''s criteria for listing threatened species, it is suggested that T. eliasi should be ranked as vulnerable in red lists. [Copyright &y& Elsevier]