A leading environmental scientist from the University of Western Sydney has revealed that parrots commonly thought of as native to Sydney, are in fact invaders from inland areas of Australia, and their growing presence is threatening our backyard bird diversity.
Associate Professor Shelley Burgin from the UWS College of Health and Science says this is due to the fashion of planting so called 'native' species in our backyards to encourage wildlife.
"Australians need to be aware that whilst they may think they are helping native wildlife and the environment by planting Australian native plants, there are many plants including cultivated hybrids that are not truly native to Sydney and its surrounding areas," Associate Professor Burgin says.
By planting colourful grevilleas and other cultivated hybrid species in areas where such plants would not naturally grow in the bush, Australians are changing the demographics of our wildlife and encouraging some bird species in favour of others.
"Australians are unwittingly impacting on the living patterns of some parrot species and threatening whole colonies of other species such as heath birds by planting native species that are not indigenous to their local area," Associate Professor Burgin says.
Associate Professor Burgin studied museum records from 100 years ago and found records of only two parrot species - the turquoise parrot and the ground parrot - and a variety of heath birds within 10kms of the Sydney GPO. These birds no longer live in the city because their habitat has been replaced.
Associate Professor Burgin says other parrot species have come to live in suburbia because a habitat and an abundance of supplementary food has been provided for them, both in private gardens and public areas such as parks. This has resulted in increasing numbers of species such as rainbow lorikeets.
"By encouraging these parrots, we now know that we may have inadvertently caused the extinction of native birds that once thrived in Sydney's bushland," Associate Professor Burgin says.
"Other common landscaping 'fashions' such as having an expansive green lawn, encourage magpies and aggressive noisy miners into our backyards - causing them to dramatically increase in numbers and further excluding or dominating other native birds."
While the suburbs of Sydney continue to expand and new housing developments flatten native scrubland and bush, Associate Professor Burgin urges developers and homeowners to think twice before choosing that colourful hybrid grevillea or that expansive green lawn, and instead consider replacing the bushland that has been lost with plants that are truly native to the area.
Source: University of Western Sydney
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