Wings of hope for endangered Eltham Copper Butterfly
Photo: Elaine Bayes, Wetland Revival Trust
Over 400 Sweet Bursaria (Bursaria spinosa) shrubs are being planted over the coming months by volunteers to increase the habitat for a local population of this rare butterfly species.
The Yarra Valley Water initiative is part of ongoing efforts to increase the available habitat of the Eltham Copper Butterfly.
Thought to be extinct in the 1950s due to habitat destruction, the Eltham Copper Butterfly was rediscovered in 1986. It has been listed as threatened since 1991.
Yarra Valley Water Biodiversity Officer Chris Farrow said by giving nature a helping hand it is hoped it will do the rest.
“The Eltham Copper Butterfly is a local treasure with its shimmering copper wings,” he said. “It’s a gorgeous little butterfly, about the size of your thumbnail.”
“We have a couple of the butterfly populations on Yarra Valley Water land and neighbouring areas, which are monitored by the Friends of the Eltham Copper Butterfly citizen science group,” he said.
The butterflies are especially vulnerable to threats because they rely on a single plant for food and a single ant species for protection.
“These little butterflies have an amazing symbiotic relationship with the Sweet Bursaria (Bursaria spinosa) plant, and a specific type of ant, the Notoncus, that lives in the root of this plant,” he said.
“These butterflies rely on the plant and the ant for their survival. By planting these species, the volunteers have directly contributed to extending the butterfly's available habitat and providing essential food and shelter.”
While the newly planted shrubs will take time to mature and create a thriving habitat for the Eltham Copper Butterfly, Mr Farrow said the initial success of the project is a significant step forward.
“These three species really do depend on one another. The butterflies lay their eggs on the lower stem of the plants.
“When the larvae hatch, the ants shepherd and guard the caterpillars into the nest where they’re safe during the day. They then come back up into the trees at night to feed on the leaves.
“In return, the caterpillars excrete a sweet sugary substance from their skin, which the ants feed upon. Once the butterflies emerge in their final form, they then go on to pollinate the Sweet Bursaria flower and lay their eggs on the plant again. It’s an amazingly delicate relationship which the three species share.”
Yarra Valley Water’s 2030 Strategy outlines the utility’s robust and proactive approach to biodiversity and land management.
Yarra Valley Water are joining the likes of Melbourne Water, Parks Victoria, Friends of the Eltham Copper Butterfly, Nillumbik Shire Council, and Banyule City Council in their efforts to restore biodiversity and create a haven for endangered species like the Eltham Copper Butterfly.
“We’re extending a corridor of habitat that will link different populations and hopefully give them the space to diversify and increase in numbers,” Mr Farrow said.
Mr Farrow said the project serves as a great example of Yarra Valley Water’s commitment to conservation. “By working together, volunteers and landholders can make a real impact on protecting endangered species and preserving our city’s unique biodiversity.”
“A huge thanks to the Bungalook Native Nursery and the Yarra View Bushland Nursery for supplying the plants for the revegetation project. By combining the stock of various local nurseries, we are hoping to create a genetically sustainable and resilient ecosystem for the Eltham Copper Butterfly to thrive in,” Mr Farrow said.