Improving the conservation and translocation of an endangered orchid through understanding threats, pollinators, and population viability

Abstract Plant translocations are used to mitigate extinction risk but are often unsuccessful, partly due to a failure to take the ecology and threats of species into account. For the endangered Caladenia formosa we used an integrated method that incorporated identification of the pollinator(s), possible threats, and population demographics to determine a suitable translocation site and subsequent management interventions. The thynnine wasp Phymatothynnus pygidialis, the sole pollinator, removed and deposited pollen while feeding from the labellum on small amounts of sucrose. We translocated 179 symbiotically propagated, flowering plants to a site where this pollinator was present and monitored the translocation and a wild site for 8 years. Monitoring revealed herbivory (6.4%) and florivory (11.8%) was high in the wild population, but negligible in the fenced translocated population. Protection from florivory enhanced fruit set in the translocation (37.2 ± 3.1% SE) compared with the wild (27.5 ± 6.5% SE) site. Population viability analysis informed the decision to supplement, which boosted overall fruit production. We demonstrate the importance of an integrated approach to translocations and highlight the role of monitoring to elucidate threats, prioritize actions and contribute to growing evidence for pollinator specialization in rewarding orchids.