Butterfly numbers soar as habitat restoration pays off
Published 06 August 2026
Annual surveys by ecological specialists Wildlife & Ecology, at a Yarra Valley Water site in Eltham, found larvae population numbers had increased almost fivefold, rising from 17 larvae found on 10 plants, to 82 larvae on 29 plants.
Researchers also found butterflies are expanding further up the hill towards a nearby Yarra Valley Water site where a protected habitat is being established, suggesting years of restoration work are beginning to reconnect habitat across the landscape.
Yarra Valley Water Biodiversity Officer Chris Farrow said the results were an encouraging indication that habitat restoration efforts could be helping the species recover.
"For a butterfly that was once thought to be extinct, these are the sort of signs you hope to see," Mr Farrow said.
"It's particularly pleasing to see these results after many years of dedicated work by Friends of the Eltham Copper Butterfly, Nillumbik Shire Council and Yarra Valley Water, to restore and protect habitat across the area.
“As a water utility, caring for Country for the natural systems we operate within is fundamental to what we do. That's why Yarra Valley Water invests in projects like this - restoring habitat helps strengthen local ecosystems, protects our waterways and supports biodiversity.”
"We've seen a big jump in larvae numbers at our site, which suggests we're creating the conditions needed for the butterflies to thrive."
The nationally endangered Eltham Copper Butterfly (Paralucia pyrodiscus lucida) was once thought to be extinct before being rediscovered in Eltham in 1986. Today, it is still only found in a few locations and depends on a rare three-way relationship with the Sweet Bursaria (Bursaria spinosa) shrub and Notoncus ant, that lives in the root of the plant.
Building on the success of recent restoration works, Yarra Valley Water is preparing to expand the restored habitat area, to create the conditions required for future butterfly populations.
"What's particularly exciting is that we're now seeing signs the butterflies are naturally moving into areas where we've been improving habitat," Mr Farrow said.
"As numbers continue to grow, our hope is they'll start establishing themselves in these new habitats without any intervention from us."
If natural colonisation does not occur, there is potential for carefully managed translocation of Eltham Copper Butterfly eggs in the future.
"Conservation takes time, but results like these show the effort is worth it," Mr Farrow said.
"Every new habitat we create gives these butterflies another chance to survive and flourish for future generations.”
The project forms part of Yarra Valley Water's ongoing commitment to protecting and enhancing biodiversity, helping create healthier ecosystems for threatened plants and animals in line with its 2030 Strategy.