The corella flocks have been allowed to increase to plague proportions and now are the largest group of birds seen in Australia.With farm lands supplying seed and water in abundance, it has seen the flocks grow to an estimated 100.000 in South Australia, with even more in the other states.
They are now at a plague level, destroying trees, eroding river banks, polluting water ways, and most importantly driving other animal and bird species to the point of extinction. The destruction and removal of other bird and animal breading sites is lowering the breeding numbers of Nankeen Night Heron, Rosellas, Frogmouths, Kookaburra etc. The sheer numbers are scaring away many species. They also take nesting places normally used by other birds. The destruction, de-leafing of eucalypts has seen Koala trails decimated, and many ancient trees may never recover. In Old Noarlunga the flock sizes have now reached in excess of 22,000 roosting in the adjacent national park at night. The health issues with such huge amount of feathers, dust and faeces are putting our children and elderly at risk with lung and bird carried illnesses. The erosion and digging into the river banks by vast numbers has seen the river in-filled to a point flood risk is now high. The river has gone from some twenty feet deep to the now approximately eight feet deep due to the silting and leaf/bark pruning by the corellas.
Houses that are built on the banks have seen over a metre disappear in two years, and each metre puts at risk the homes. The river pollution has seen the whole riparian system changed and warning signs placed along the river as to bathing and the eating of fish. The corellas started in large numbers in the late 1990's and were rarely seen with flocks over a couple of hundred before that.
In the last ten years the flocks have been able to increase to the numbers seen today because of the supply by man of food (seed/grain) and water. Natural breeding numbers used to be inhibited by food availability until huge areas of land were opened up for cropping by farmers. This is a man made disaster and it's up to man to come up with effective management of the problem, as quickly as possible before even more harm is done.
For updated information on the Corella issue, please see our Newsletter page.