Bird boom in Broken Hill

By John Pickrell 11 October 2012
Reading Time: 3 Minutes Print this page
Following the rains, shrubland songbirds are booming in the outback plains west of Broken Hill.

STARTING IN LATE 2009, heavy rains began to drum down upon the windswept and dusty saltbush plains and open mulga woodlands of Boolcoomatta, 100km west of Broken Hill in the South Australian outback. The return of sustained rainfall after a 30-year absence was much welcomed by both wildlife and conservationists. Since 2006, this 63,000ha former sheep station has been managed as a nature reserve by conservation charity Bush Heritage.

Insectivorous ground- and shrub-feeding birds are heavily impacted by livestock and are in decline across much of Australia – but not here. The end of sheep farming along with the abundant rainfall of the past two years has brought about some significant improvements. There have been large bird increases – particularly the kind Bush Heritage’s science and monitoring manager Dr Jim Radford refers to as “LBJs” – short for “little brown jobs”.

“On the saltbush plains the dawn chorus is a cacophony of rufous field-wrens calling and white-winged fairy-wrens trilling,”  he says. “You won’t necessarily see a lot, because they are small shrub-dependent birds flitting around in the scrub – but there’s a lot of activity. If you go down to the creek line you’ll see singing honeyeaters, spiny-cheeked honeyeaters and rainbow bee-eaters flitting around, as well as fairy martins, tree martins and chestnut-crowned babblers. It’s thrilling to see things darting around in huge numbers and not having to search for them.”

The way these little birds have bounced back really has Jim excited. “We’ve detected some meteoric rises,”  he says. Overall, Boolcoomatta has undergone a doubling in insectivorous species richness between 2006 and 2011. White-winged fairy-wrens are up 235 per cent, rufous fieldwrens 395 per cent, chestnut-crowned babblers 165 per cent and redthroats a whopping 655 per cent. These are not necessarily endangered, but we shouldn’t take them for granted, says Jim.

Bird numbers booming in the outback

To monitor numbers, his team uses an intensive bird-survey technique called ‘bird minutes’. During the spring breeding season, they go out on the saltbush plains and measure the amount of birdsong, which they are able to equate to bird numbers in a given area. It’s a clever method they’ve developed to detect changing populations in birds that can be difficult to see.

“We were already seeing increases because of the release in grazing pressure, but when it was really wet last year, there were birds everywhere,” says reserve manager Peter Ashton. “Budgies and cockatiels, quails, brown songlarks, orange and crimson chats and many raptors too – eagles, barn owls and tawny frogmouths.”

He says 1974 and ’75 were the last two back-to-back wet seasons, illustrating how rare current conditions are. “It was really dry up to November 2009. Then we got about 100mm between November and the end of the year. In 2010 we got 500mm and in the first part of 2011 we had another 200mm.” This is a lot when you consider the average rainfall out here is 190mm a year. 

“The rains have had a big effect, there’s no question about that,” Peter says, but he’s keen to see what will happen now. He and his wife Emma have been working hard to manage the reserve, clearing it of livestock and feral animals and removing dams. They hope they will never see a return to the low bird numbers of 2006, when Bush Heritage first acquired the property. Bumper wet seasons should now allow birds to thrive, creating populations more resilient to lengthy dry periods.

Jim says it’s rewarding to see the boom. “What I really appreciate is that occasionally I’ll have finished the survey, and I’ll just be able to sit back and look at a mulga parrot or a red-backed kingfisher perched in a tree, and take that reflective moment to think how lucky I am to do this job. Taking time to appreciate the beauty of these birds is important – and the opportunity to do that when there are so many more of them is good for the soul.”
Source: Australian Geographic, issue 106 (January – February, 2012)