Thanks to the City of Playford’s council spokespersons for their assistance with this article.]
November 5, 2018, the Mount Barker District Council issued a “scaring” notice for Little Corellas, following their April 3, 2018 decision endorsing “selective legal shooting” of flock leaders, or “scout” corellas. The measures seek to discourage flocks, especially the largest flock, from summering in the area. Longer term the Council is undertaking habitat modifications like altering lake banks, in-planting beneath eucalyptus trees, and altering creek shorelines to make it harder for birds to access the standing water, and so discourage flocking.
Mount Barker, South Australia, just 21 miles from Adelaide’s city centre, is not the only local council to have taken action. In February, the Playford Council launched a campaign to remove the flocks of Little Corella “plaguing” the community. The Playford News reported that local complaints included that the “large and noisy flocks” damage trees, town squares, recreations areas, buildings and other infrastructure. “Infrastructure” is not a particularly clear term. Suffice it to say, the birds are known to cause damage to electrical wires.
According to Mayor Glenn Docherty, as reported by Playford News, the birds caused significant damage and escalating clean-up costs. Playford allegedly took action against the Little Corella having “been advised by bird-strike experts that recent weather patterns have created an abundant food supply for Corella to flock to Adelaide and its outlying regions.” Further, the Little Corella have lost some of their traditional range due to increased urbanization. In short, the City of Playford understood that without intervention, the Corella could potentially remain for months, rather than the usual several weeks, breeding rather than flying off to their traditional breeding ground.
Little Corellas, Cacatua sanguinea, also known as the bare-eyed cockatoo, blue-eyed cockatoo, or short-billed corella, is a smaller cockatoo native to Australia and New Guinea. Little Corellas weigh in at just over one pound, being about 15 inches/40 centimeters in length.
Long-billed Corellas (see below right), unlike Little Corellas, are protected under South Australian law. However, they may flock with Little Corellas. Thus, care must be taken in flock management of Little Corellas, that the measures not adversely impact protected birds. Shooting must be undertaken with caution, as the authority to kill a protected species is only granted by permit.
Initially Playford contracted to disperse flocks from known roosting, flocking and feeding sites with “bird-scaring devices and pyrotechnics.” In June, when damages had reached over $60,000, Playford changed tactics. Mayor Docherty indicated that fear-tactics had backfired– the Little Corella had started to associate large noises with fertile feeding grounds. So the City mobilized its two falcons, Ziggy and Lucy.
By update kindly provided by a City of Playford’s council spokesperson, we can report that, in fact, falcons did encourage the birds to move on, in keeping with their general migrational path, breeding elsewhere. As the spokesperson explained, “natural predators trump noise (such as gas guns) as a deterrent. The birds have an innate fear of falcons, so just the appearance of them will drive a flock on – even if they don’t kill. It is a primal reaction and they understand that falcons mean death.”
While the Little Corella flocks overstayed their traditional period in the area, engaging in flock management meant the City could reduce expensive physical damage to infrastructure. Practically speaking, Playford’s council spokesperson additionally pointed out that, the while loud sound deterrence did not drive away the flocks entirely, it did have valuable impact: “using noise as a deterrent will scatter flocks, which does ameliorate the damage of huge flock numbers in the thousands.”