Society must question what matters to it if it is to stop birds from disappearing, experts warn after it was discovered that bird numbers in forests in the Mount Lofty Ranges have declined 45 percent in two decades.
The number of woodland birds in the Mount Lofty Ranges has declined significantly since European settlement
Habitat clearance has been blamed for the decline
Experts believe that large-scale habitat restoration is the only way to bring birds back
A University of Adelaide paper published earlier this month revealed that “specialty birds” such as magnificent fairy wrens and New Holland honeyeaters had declined significantly in ranges, largely due to habitat degradation and clearance.
It found that 75 percent of birds that relied on forests were affected, while 58 percent of bird species overall were in decline.
“Those birds that are disappearing from the landscapes we all live in are really telling us that none of us are living sustainably in our landscapes,” said South Australian ecologist David Paton.
“I think it raises some fundamental questions about what society wants and what we value?”
Other badly affected birds are the European goldfinch, chestnut-tailed heather fence, brown and striped thornbill and sacred kingfisher.
Clearing vegetation lowers the numbers
The University of Adelaide study, conducted by its Center for Global Food and Resources, used data from the Mount Lofty Ranges Woodland Bird Monitoring Program, which has been running since 1999.
The program includes visiting 151 sites from Truro to Cape Jervis three times a year.
Lead researcher and President of the Nature Conservation Society of SA Patrick O’Connor said grazing pressure from stocks, wild animals and abundant kangaroos has degraded the quality of forest habitat along with mandated burns.
“There is a long-term trend towards removing vegetation and clearing,” the associate professor told ABC Radio Adelaide.
At the same time, however, the opening of the country had led to an increase in large-bodied carnivorous and “sociable birds” such as galahs, sulphur-crested cockatoos and parakeets.
“These species like more open habitats, so if we remove the middle and undergrowth they can compete better,” Mr O’Connor said.
A “depressing” condition
Birds SA, or the South Australian Ornithological Association, was formed in 1899 to become the country’s oldest bird watching association.
Its Bird Protection Secretary, Graham Carpenter, has been involved in birdwatching for 40 years and has noticed an accelerating decline during that time.
“There are certainly places that I went to as a kid, like Belair National Park, where I saw 50 species of birds in one day,” he said.
These included birds like the black-chinned honeyeater, the robin, and Jacky Winter.
“Even before I got into birding, there were birds that people saw in the 1930’s that were gone by the time I got started,” said Mr. Carpenter.
“It makes me very depressed.
“I take a younger person and they see 20 birds in one of these spots where I used to see 50 and they’ll think that’s really good because they have nothing to compare.”
David Paton, Associate Professor at the University of Adelaide, is Director of the non-profit group Bio R.
He said Bio R is working to recreate native habitats, having recently “brought back about 175 hectares of complex habitat” at a farm on Kangaroo Island.
This meant that land that only supported one bird per hectare, like magpies and other common species, now supported about 10 birds per hectare.
dr Paton said the Mount Lofty Ranges had been cleared of all but 10 percent of its vegetation by European settlers, and although it was the first state to introduce legislation to prevent further large-scale clearing, the damage had been done.
“It’s been around since the 1980s for the most part, but with only 10 percent of habitat left, unless you give back more habitat on a large scale, you’re likely to lose half of the forest bird species,” he said.
“Many of these struggling bird species have home ranges of 200 hectares, the equivalent of 200 football fields, of quality forest habitat, and there are very few places in the Mt. Lofty Ranges that have that much habitat.”
Large-scale approach required
Some other ongoing restoration projects include 500 acres in the Para Woodlands Conservation Area near Gawler.
It is a former farm donated to Nature Foundation SA by Elizabeth Law-Smith and her husband David and includes land also donated to the cause by the Department of Environment and Water.
And early last year, the state and federal governments pledged $1.2 million to a Woodland Bird Resilience Program aimed at restoring habitat destroyed by the Cudlee Creek bushfire in late 2019.
Mr O’Connor said birds could be seen as an “indicator set” of a general decline in ecosystem function.
He said society has the knowledge and ability to restore the systems and it can be done in a way that benefits both people and the landscape, but the restoration hasn’t gone far enough so far.
“But if you were a store owner, 45 percent of your inventory has gone out the door in the last 20 years.
“Programs that we have running at the moment are roughly on the order of the yogurt replenishment.”