Rapid assessments of amphibian diversity

More than 6400 amphibian species are known worldwide, with more than 50 new species being described in just the fi rst half of 2008 (AmphibiaWeb 2008). Many of these species are threatened or declining and more than 150 may have recently become extinct (IUCN 2006). Such rates of species loss are far greater than the historic background extinction rate for amphibians (e.g. McCallum 2007; Roelants et al. 2007). Amphibians play diverse roles in natural ecosystems, and their decline may cause other species to become threatened or may undermine aspects of ecosystem function (Matthews et al. 2002; Whiles et al. 2006). Anthropogenic habitat loss and degradation, disease, introduced species, and pollution or combinations of these factors are at the root of most declines. As awareness of declines has increased, conservation groups, governments, and land managers have become more interested in protecting amphibian diversity. However, the lack of accurate data on amphibian distributions, particularly for tropical regions where diversity and declines are concentrated (IUCN 2006), is often a roadblock to effective conservation and management. Ideally, lack of information on the amphibian fauna for a particular area would result in a thorough inventory. Unfortunately, this is usually not realistic. Exhaustive inventories are costly and may take decades to compile (e.g. Timm 1994). Given the urgency of the current global biodiversity crisis, fi nite resources, and dynamic socio-economic environments with respect to conservation, an approach for rapidly gathering preliminary data on biodiversity is sometimes required. Rapid biodiversity-assessment methods were developed in response to this need. A Rapid Assessment (RA) is an accelerated, targeted, and fl exible biodiversity survey, often focusing on species associated with particular vegetation