Diuris fragrantissima 

This recovery program draws on the expertise of Zoos Victoria’s horticultural staff in the propagation of the Critically Endangered Sunshine Diuris Orchid. The program is tackling the ever-increasing loss of Victoria's grassland habitat by restoring some of the remaining grassland remnants in an effort to retain the biodiversity that these ecosystems support.

The Program Focus

The Sunshine Diuris (Diuris fragrantissima), an Australian native orchid, was once common on the basalt plains immediately to the west of Melbourne, where it grew in native grasslands dominated by Kangaroo Grass. However, as far back as 60 years ago, concern was expressed about its decline, which continued ever since. In 1992 the wild population was down to one known flowering plant at one site. It is one of the most endangered orchids in Australia.

The long-term goal of the recovery program is to achieve a number of viable populations of the plant in the wild.

The Conservation Issue

Grasslands once covered 10% of Victoria but since European settlement, agriculture and industrial and urban development to the west of Melbourne have all but destroyed these, with only 0.1% remaining (State of the Environment Report 1991). This loss of grassland habitat has been responsible for the virtual extinction of this orchid in the wild.

The remaining grasslands are small, degraded and fragmented, making them vulnerable to other environmental and human influences. Lack of fire, invasion by Chilean Needle-grass and other weed species, predation by slugs and snails, vehicle movement and illegal collection all pose threats to the remaining population of this orchid.

There is also concern that, with so few plants in the wild, the natural pollination process may have been altered, making it difficult to regenerate in the wild.

Zoos Victoria’s Conservation Field Partners

The recovery of the Sunshine Diuris Orchid is the work of a number of organisations and community groups which are members of the Recovery Team. Each Recovery Team member brings particular expertise to the recovery effort, ranging from captive breeding, habitat management and predator control to education and research. Members of this team include:

Department of Sustainability & Environment
Department of the Environment and Water Resources
Royal Botanic Gardens Melbourne
Australasian Native Orchid Society
City of Brimbank
City of Hobsons Bay
University of Melbourne
RMIT

Community volunteers
Other supporters of this work include the Port Phillip & Westernport Catchment Management Authority.

The Program Plan

The objectives of the Recovery Plan 1999–2003 are to:

1. Maintain and increase the population of the Sunshine Diuris at Sunshine.
2. Maintain the Sunshine Diuris in cultivation.*
3. Investigate factors affecting plant recruitment and population viability.
4. Establish a new population of the Sunshine Diuris.
5. Manage the recovery program for the Sunshine Diuris.

*Melbourne Zoo's core contribution is to this objective

Zoos Victoria's Role

Zoos Victoria's key roles in the recovery of this species are to:

1. Supplement in situ populations through captive breeding for reintroduction; and
2. Maintain an insurance population in captivity in the event that the wild population continues to decline.

Zoos Victoria has been involved in the Recovery Program for the Sunshine Diuris Orchid since 1993. In September 2004, the first of a series of introductions of the Sunshine Diuris Orchid occurred at a grassland remnant west of Melbourne. In total, 700 plants have been trans-located, all of which were cultivated at Melbourne Zoo. Zoos Victoria’s support for this program is ongoing.

Reports and Publications

Sunshine Diuris (Diuris fragrantissima) (Orchidacea: Diuridinae) Recovery Plan 1998–2002