council
Background
The Indian Myna (or Common Myna) bird – Acridotheres tristis – was firstly introduced into Melbourne’s market gardens in the 1860s in a misguided effort to keep down insect numbers. They were then taken to Cairns and other northern centres to control insects in cane fields as well.
The Indian Myna, unsurprisingly, originated in India, where it is called the ‘farmer’s friend’ because it eats insects that destroy crop plants. Even though the pest eradication plan for the introduced myna was not successful in Melbourne, they were nevertheless, as mentioned above, taken to many other places in Australia.
They have since become very successful invaders of our natural environment and our urban environment as well – the urban fringes surrounding our cities are well suited to these myna birds. Large gums trees provide plenty of nesting hollows and urban areas provide an abundant food source. In many areas they are thus considered an animal pest.
The Indian Myna and the Noisy Miner
What’s the difference?
The Indian Myna, as mentioned above, is an introduced species into the Australian environment; whereas the Noisy Miner is a native species. The bad news for some affected people is that both species can be a very, very noisy type of bird!
The common Indian Myna is a medium sized chocolate brown bird, about 12cm tall, with a black head and neck, and a yellow beak, eye patch, feet and legs. White wing patches are obvious when the bird is flying. Juveniles look a bit different but can still be recognised as mynas.
Native Noisy Miners (Manorina melanocephala) on the other hand are predominantly grey in colour with flesh coloured feet but they also have a yellow beak and a yellow patch around their eyes. They are described as aggressive Australian honeyeaters that dominate many areas of remnant vegetation and forest edges from which they competitively exclude small native birds. Being native they are thus a protected species.
Both birds are a very gregarious species and are also a very aggressive type of bird in that they are very good at excluding other bird species from their shared habitats. They are both considered to be very successful from this point of view, and certainly their numbers reflect this ability to thrive in our now human-modified environments. For example, in Cairns, the number of Indian Mynas per square kilometre is now estimated to be between 750 and 1200 individual birds!
Humans have also modified other habitats to the benefit of such birds as the Noisy Miners and thus to the detriment of other native bird species.
A decline in populations of small native birds in Australia’s agricultural landscapes has been identified. The planting of wildlife corridors connecting fragments of native vegetation has been used in the past to try and prevent this decline. However many such corridors have existed predominantly of eucalyptus trees. When such corridors run through pasture, they form habitat similar to forest edges. Such edges are often naturally dominated by the aggressive native honeyeater, the Noisy Miner, to the detriment of small native birds.
Thus these corridors, rather than providing safe passage or habitat for small native birds, may actually be counterproductive and may be providing more habitat for and helping to spread a substantial threat to small native birds in agricultural areas, the Noisy Miner.
The lesson to be learnt here and one which can be applied to the problem of increased Indian Mynas in urban environments is that the type of habitat we provide for our native birds is crucial if we are to improve the current imbalance in bird numbers.
The Indian Myna bird problem
As mentioned the Indian Myna in Australia is a very successful species – they thrive in the habitat that we humans have provided for them in our urban areas.
They are very successful breeders and move around in communal groups, sleeping at night in communal roosts as well. Up to several hundred birds may gather at these communal roosts, which are usually in trees or other dense vegetation, although roosts can also occur in creepers, buildings or under bridges. There are usually several roosts in each suburb.
Indian Mynas can become a serious problem because they damage fruit and grain crops in agricultural areas and their noise and smell can become annoying when their numbers increase. They can also spread mites and have the potential to spread disease. Mynas also reduce public amenity through noise at communal roosts and extensive fouling with their droppings.Biodiversity
Indian Mynas as described above are a successful introduced species which compete with native wildlife. In the Sydney region, this competition can be largely seen through their competition for food and nesting sites with small native birds and other larger native birds, which for instance roost in tree hollows. Such hollows are in short supply over much of Australia because of excessive clearing for agriculture and urban development and the removal of mature trees.
Common Indian Mynas often nest in tree hollows and reduce biodiversity through predation and by fighting for hollows with native birds such as Rosellas. They will also destroy the eggs and chicks of native birds and stop them from breeding. Mynas are capable of evicting even large birds such as Kookaburras from their nests. They also sometimes evict small mammals such as Sugar Gliders from hollows – spelling certain death for the young gliders as they often have nowhere else to go. It is not uncommon for groups of mynas to mob other birds and even possums.
Regional coordination of the Indian Myna bird problem
Currently the Urban Feral Animal Action Group (UFAAG) is reviewing the control methods, the effectiveness and the resourcing requirements for a regional eradication program for the Indian Myna.
Parramatta Council will consider the decision of the UFAAG which will be made in May 2009, as to whether or not a regional eradication program for the Indian Myna will be undertaken. This regional program if undertaken will be coordinated by the UFAAG.
For more information on best practice feral pest management principles and program priorities please refer to pages 18, 19 and 20 in the following document
