Published: 14 February 2014
Rare native bird populations decimated by Mallee fires
The devastating fires that swept across South Australia and Victoria during January’s heatwave have killed entire populations of threatened native birds, ecologists say, calling for urgent action to prevent extinction.
Following the recent fires, the global population of the mallee emu-wrens is now restricted to a single reserve system in Victoria – one big fire could render the species extinct.
Credit: Simon Bennett/Austral Avian images
Lightning strikes are believed to have started one of the fires, which burned through the entire 13,000-hectare Bronzewing Reserve – a vast area of wild mallee scrub in north-west Victoria, 12 kilometres southwest of Ouyen – in mid-January.
Fires ignited two conservation parks in South Australia's Mallee region that were home to the only remaining South Australian populations of the endangered mallee emu-wren, a tiny bird with distinctive emu-like tail feathers.
The SA fires completely engulfed the Billiatt Conservation Park with over 67,000 hectares burnt, while all remaining emu-wren sites within the Ngarkat Conservation Park burnt in two separate fires.
The fire-devastated Bronzewing Reserve was home to one of two small populations in Victoria of the endangered black-eared miner. The only other population of this species resides in South Australia's Riverland Biosphere Reserve. Around 35 per cent of all black-eared miner habitat in the reserve was burnt.
‘Birds like the black-eared miner and mallee emu-wren have little chance of ever naturally repopulating these burnt-out areas due to the highly fragmented Mallee landscape, coupled with their limited dispersal capabilities,’ says the University of Adelaide's Dr Rebecca Boulton.
She leads a decade-long recovery effort aimed at boosting numbers of the black-eared miner through captive breeding and translocation programs, the release of female birds into new colonies and habitat management.
‘Fire, and its threat, is a familiar occurrence each summer for many Australian residents living amongst our flammable habitat,’ she says.
‘For our wildlife, adaptation to fire is a common life-history strategy. Yet with land clearance, isolating and restricting many species' distributions, large bushfires now seriously threaten many species' survival.’
Her colleague, Dr Rohan Clarke from Monash University's School of Biological Sciences, says breeding and recovery programs are critical to protecting endangered species.
‘The fact that we lost several significant bird populations in fires linked to a single heatwave event highlights just how vulnerable many of these species are,’ he says.
‘Following the recent fires, the global population of the mallee emu-wrens is now restricted to a single reserve system in Victoria – one big fire could render the species extinct.
‘Where wildfire is a threat it is absolutely critical that our eggs aren't all in one basket. To better manage risk we need well-funded recovery programs where the establishment of separate populations is a key measure of success.’
The recent review of Australia's bird fauna lists 27 bird species as extinct since European colonisation, with a further 20 classified as critically endangered and 60 endangered.
Source: University of Adelaide