Context: The Western Australian Environmental Protection Authority's (EPA's) terrestrial fauna survey guidelines for detailed surveys recommends a two-season survey with a minimum of one, or a few survey sites, for each fauna habitat. Aims: This study demonstrates that in two common fauna habitat types and probably most others, this survey effort is unlikely to provide an indication of species richness and abundance. Methods: A pit and funnel trapping program targeting small ground dwelling mammals and reptiles was replicated in 20 trapping sites over two survey periods in two different fauna habitat types. Results: For most project areas, compliance with the EPA's guidelines is unlikely to provide better quality data on species richness than publicly available from a desktop assessment. Conclusion: It is difficult to provide an adequate scientific justification for undertaking low intensity surveys when desktop surveys will mostly provide better quality information for an environmental impact assessment (EIA), and these surveys probably should not be approved by an animal ethics committee. Implications: When preparing for and undertaking vertebrate fauna surveys for an EIA, environmental practitioners should place greater emphasis on the scientific validity and robustness of the proposed surveys rather than just complying with an EPA technical guidance. The EPA's technical vertebrate fauna survey guidance should be completely rewritten. Here, we analysed the data from two terrestrial fauna surveys undertaken in different fauna habitats that are common in Western Australia. Although environmental practitioners comply with the Western Australian Environmental Protection Authority's (EPA's) terrestrial fauna survey guidelines when surveying one site in each fauna habitat type, these surveys typically collect insufficient data to record more than 60% of the terrestrial species present. They are also unlikely to provide better quality data on species richness than publicly available from a desktop assessment. In addition, it is difficult to provide a scientific justification to an animal ethics committee for undertaking low intensity surveys when desktop surveys may provide adequate information for an environmental impact assessment. Therefore, these surveys probably should not be approved. We argue that the EPA should rewrite its existing guidelines. [ABSTRACT FROM AUTHOR]