News and Views

Ferals and the food chain

Have you heard the one about how a pretty pest plant led to the downfall of a feral animal, which led to sightings of Australia’s largest birds of prey and critically endangered reptiles?

Natural Resources Adelaide and Mt Lofty Ranges officers never know what will happen day to day.

An Inman Valley landholder contacted Natural Resources AMLR to report ‘seeing a sea of pink’ when gazing out of their kitchen window onto a hillside of remnant vegetation on a neighbouring property. On investigation it was identified as Erica Baccans (berry heath) a declared weed, a threat to native vegetation and the only known infestation within the southern Fleurieu region.

While staff and contractors were mapping and controlling this weed, two free-roaming goats were found to be living in the remnant vegetation. Free-roaming, unidentified goats cause a lot of damage, are classed as “Feral” under the South Australian Government Declared Animal Policy and must be controlled. An experienced contractor was engaged to undertake this task, under a new NRM – levy funded project to prioritise emerging pests on the Fleurieu.

Due to the location and quality of the habitat on this property a remote camera was set up to see what introduced or native species would utilise the carcases.

After two weeks staff went and collected the images from the camera.

They were amazed to see a family of Wedge-tailed Eagles, Australia’s largest birds of prey and a legally protected species, were seen feeding over 3 days (see featured image).

A recent article in the SA Ornithologist on Fleurieu Peninsula wedge-tails, states 44 active territories were found in 2017, with 38 producing young. This equates to about one pair per 30 square km. The population on Fleurieu Peninsula has been stable over the last 10 years.

A very healthy Heath Goanna, was also captured on film as they too are partial to scavenging on carrion to supplement their diet.

In the Mount Lofty Ranges, Northern and Yorke Peninsula, Eyre Peninsula, Murray Darling Basin and the South East regions, the Heath Goanna is Critically Endangered. It is estimated that less than 100 individuals remain in each of these regions.

In SA the Heath Goanna is classified as Vulnerable. Once common across the higher rainfall, cooler areas of southern Australia, it has suffered dramatic declines on mainland SA, largely due to land clearance, habitat fragmentation and degradation, road deaths and predation by cats, dogs and foxes.

But back to the weed which started all this excitement! Staff continue to work with the landholder, undertaking follow up control of Erica baccans, but now they’re also investigating opportunities to undertake more biological surveys on the property, to help develop a plan for ongoing protection of the local native flora and fauna.

If you would like to follow up any of the information above you can contact Lisa on:

Lisa Blake
District Officer – Parawa
Sustainable Landscapes
Department for Environment and Water
P (08) 8550 3409 | M 0429 475 986
5 Aldinga Rd PO Box 781 Willunga SA 5172

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