Has the cross-border Silver Xenica butterfly translocation been a success?

It is with great enthusiasm that we can provide an update to this long term project!

As you will read from our original post we believed the population was in dire need of help. Since the millennium drought of 2006-07 the Silver Xenica butterfly had not been seen in South Australia – despite searches some years later in March and April 2014. Then in 2017-18, Michelle Sargent and I prepared the translocation plan for the Silver Xenica butterfly in South Australia which was an action from the Swamp Gum Woodland Regional Action Plan.

Silver Xenica roosting in Overland Track NFR – April 2020.

In 2018, 40 females were captured from the closest known stronghold for the species (near Dartmoor in western Victoria) and then released into two native forest reserves in SA (20 in each reserve). In 2019, we visited the SA release sites BUT no adults were seen flying in either reserves. Hmm, “it hasn’t worked,” was the first conclusion. We decided the best approach was to wait for one more year – we might have missed the butterflies during the surveys or their numbers might be too low for us to detect them easily. We thought things couldn’t get much worse as they might already be extinct!!

Well, I am very pleased to report that on Easter Monday 2020 during warm and sunny conditions, Sue and Roger Black observed up to five Silver Xenica butterflies in Overland Track Native Forest Reserve – near where females were released two years earlier. What a pleasant surprise! I subsequently visited both reserves the following, day despite weather conditions deteriorating overnight, but managed to observe several individuals at Overland Track and also one female at the second translocation site – Honan Nature Forest Reserve. What a result … both sites with ‘Silver Xenica’ butterflies!!

Female Silver Xenica seen in Honan NFR – April 2020.

NGT couldn’t have undertaken this conservation project without the initial support from Natural Resources South East, NGT staff, volunteers, ForestrySA and with funding from the Restoring under-represented Ecological Communities project. As with all projects, they eventually come to an end, as this one did in mid 2018. So OneFortyOne generously stepped in to keep some of our priority tasks going in the region, which has ensured the project continues and allows us to report this positive result for the species.

Genetic diversity of populations is one follow-up question we wish to pursue to be clear we don’t have regional differentiation between the South Australian and western Victorian populations, and with the broader populations throughout its range in southern Australia.

So, in summary – the statewide extinction of this beautiful creature has been avoided (for now) – let’s hope this population continues to thrive and expand so we all continue to see Silver Xenica butterflies in South Australia. Our short video below summarises the fabulous 2020 results.

A big thanks to our current sponsor OneFortyOne.