Open Access

Brian Towle, Kylie Coutts-McClelland, Stephen Deards

• Calochilus pulchellus (family Orchidaceae) (Pretty Beard Orchid) is a listed Endangered species with a highly restricted distribution in the Shoalhaven local government area. The species was only known from a small number of populations when described in 2006. Since then very few new populations of the species have been recorded and some previously known populations have not been observed for decades. This study summarised known information regarding the distribution and habitat preferences of Calochilus pulchellus, with the aim of identifying potential habitat where unknown populations of the species may be detected by targeted surveys. Areas of potential habitat for the species were identified based upon vegetation communities in which the species had previously been recorded. A subset of the initially large area of identified potential habitat was selected for targeted surveys based on the recorded occurrence of sympatric threatened orchid species. The targeted surveys resulted in an approximately three-fold increase in the previously known population size of Calochilus pulchellus, a small range extension for the species and a doubling of the extent of occurrence. Newly discovered individuals and populations of the species have increased the understanding of habitat for the species, with a greater proportion of the total known population of the species now known to occur within woodland and forest vegetation communities rather than heathlands. Despite the additional individuals of the species detected as part of this study, the species is still only known from a very low number of known individuals and a small number of populations and has a very high risk of extinction. Consequently, identifying and protecting additional populations of Calochilus pulchellus should remain a priority for the conservation of the species.