Saving the threatened Audas Spider-orchid (Caladenia audasii) from extinction
Caladenia audasii has only 5 known plants remaining in the wild. It is endangered under the federal Environment Protection and Biodiversity Conservation Act (1999) and listed under the Victorian Flora and Fauna Guarantee Act (1988).
Three of these plants fall within the Grampians National Park and associated reserves (two of which were discovered in community surveys in 2016). These plants urgently need supplementation to remain as viable populations into the future. With such low numbers left in the wild, the populations are not sustainable and every plant has critical importance for the long term recovery and genetic resources for this species. Pollinator identification is also critical to manage the ecology of this species and reduce incidental harm to the pollinator through ignorance of its habitat requirements.
Under a previous grant, the ANPC worked with the Friends of Grampians Gariwerd (FOGG) and the Royal Botanic Gardens Victoria (RBGV) to fence the one remaining C. audasii plant in a reserve near Stawell, an action which resulted in no grazing impacts and the first ever seed being collected for propagation. The RBGV then worked with the Department of Environment, Land, Water and Planning (DELWP) to propagate and re-introduce 50 plants back into another population near Bendigo.
This project has been funded by DELWP through its Biodiversity On-ground Action grants from November 2017 until June 2020.
The ANPC is working with the RBGV, FOGG and the Australasian Native Orchid Society (Victoria Group) Inc. on this project. Achievements so far:
- Seed was collected from existing fenced sites in October 2017 and sown for propagation in November- December 2017. Approximately 50 C. audasii seedlings are now growing at the RBGV Orchid Conservation Project’s shadehouse.
- Another batch of seed was sown in August 2018 and another batch will be sown in November 2018 with new seed.
- A C. audasii plant was hand pollinated in September 2018 for new seed.
- An exclusion fence was constructed in August 2018 at one site in the Grampians to protect the newly discovered plants from grazing kangaroos, wallabies and rabbits.
- Pollinator baiting is currently underway (September 2018) at two sites, through guided volunteer pollinator baiting work (assisted by RBGV staff).
Future activities include:
- Guided community surveys (over 500 hectares) near the two newly discovered sites for any additional plants that may not have been seen previously.
- Identification of the pollinator for this orchid and its distribution.
- Propagation of more Caladenia audasii seedlings by RBGV.
- Re-introduction of approximately 200 plants, with community volunteer assistance from FOGG and the Australasian Native Orchid Society (Victoria Group) Inc. in June 2020.
- Installation of cages around reintroduced plants.
- Using the data collected to update IUCN listings, the Atlas of Living Australia, the Australian Virtual Herbarium and the Victorian Biodiversity Atlas.
- Training of volunteers in survey techniques and plant reintroductions.
Community participation and education in an endangered plant reintroduction is an important element of reintroduction success, as it engenders local ownership and ongoing interest in the species and surrounding habitat.
Contact the ANPC for further information on this project.
Left: Caladenia audasii growing in the wild. (Photo: Julie Whitfield). Right: C. audasii germinations in the RBGV Orchid Conservation Program laboratory. (Photo: Noushka Reiter)
C. audasii seedlings growing at the RBGV Orchid Conservation Program shadehouse. (Photo: Noushka Reiter)