June 24, 2022

For some, this playful, cheeky bird species is possibly the most effective gardener there is!

If you have ever seen a cockatoo or multiple cockatoos forging around in a grassy area, the chances are they have found a healthy patch of onion grass to feast on.. and this is one feast you want to encourage!

A stubborn pest weed from South Africa, onion grass spreads quickly throughout grassed areas, where they reseed and reproduce under the soil. Onion grass is notoriously difficult to control and is a severe pest to agriculture, native grasslands and turf laid for public or private purposes, e.g. lawns or nature strips.

For humans to treat onion grass weed infestations is costly and timely. Multiple treatments are needed over a period, which involves high-cost chemical sprays, and at times if severe, the removal of topsoil. Onion weed can grow all year round, and seeds can remain viable for many years in soil, which is why it is so hard to control.

Onion weed can spread so aggressively that one area can be infested with 5000 onion grass plants per square meter! Imagine the benefit of one or a flock of cockatoos feasting on onion grass where there is an infestation. Gregory Moore, from The University of Melbourne, research has found cockatoos feeding on onion grass:

  • They feed on the “corm”, which is the seed (effectively removing it through consumption);
  • Location and consumption of one corm found below the surface of the soil can take as little as six seconds and up to 30 seconds; and
  • The estimation is that one bird can consume 200 plants per hour.

Compared with expensive, moderately effective and timely control measures adopted by humans, our fun-loving cockatoos can eradicate an onion grass infestation in a fraction of the time, with a higher success rate (as they eat the seeds) and at no cost. Plus… their foraging helps aerate the soil. Way to go, Cocky!

At the Bird Advocacy Foundation (BAF), we promote better outcomes for our native bird species. We work with a range of partners to drive new initiatives which promote the availability of food, water and shelter for the preservation of our bird wildlife. Our research suggests that many challenges faced between humans and birds can be remedied with proactive planning and the implementation of wildlife support strategies.