Myna guilty of evicting native Australian birds: study

Australian researchers have come up with what is believed to be the world's first clear proof that mynas do indeed have a negative impact on native bird numbers.

Debate has raged for more than a decade about the damage caused by swelling myna populations, both in Australia and other countries, leading the pesky bird to be rated as the third most invasive species by the International Union for Conservation of Nature.

In a long running study, Kate Grarock and colleagues at the ARC Centre of Excellence for Environmental Decisions (CEED) and Australian National University investigated 20 birds species around Canberra, analysing ornithological records collected by the Canberra Ornithologists Group (COG).

 

A total of 74,492 surveys were conducted in Canberra over 29 years.

"We found a negative relationship between the establishment of the Common Myna and the long-term abundance of three Australian cavity-nesting species and eight small bird species," Grarock said in a CEED statement.

The birds most affected by mynas include the sulphur-crested cockatoo, crimson rosella, laughing kookaburra, and small birds such as the superb fairy-wren, striated pardalote, rufous whistler, willie wagtail, grey fantail, magpie-lark, house sparrow, silvereye and common blackbird.

Larger birds like magpies, wattlebirds, galahs, ravens and currawongs appeared unaffected.

"To the best of our knowledge, this finding has never previously been demonstrated at the population level.It is particularly difficult to track the impact of an invasive species on native wildlife when it isn't an actual predator, as this can take place subtly and over a long time and can vary season by season," she said.

"Also you need to know whether it is the invader that is causing the damage