Many will be tired of this subject, others will remain interested, perhaps fascinated by the feelings aroused. I am a little concerned we are all being pushed into corners, which does not help understanding of what is going on out there. May I therefore state my position, and what I am concerned about. I have been interested in birds for more than 60 years, and I have known the C Myna for nearly as long as that - from its adopted homeland around Melbourne. I have watched its expansion in the local woodlands over more than 30 years, and I believe it is an aggressive competitor for nesting hollows.
I do not particularly like the species. We would be better off without it. I support the efforts to eliminate it, if that is what people think is the best use of their time in regulating the relative proportions of species present in the natural world around us. I do not think it appropriate to whip up emotion about it, because this is a distraction from many other unfortunate things that are going on in the natural world.
I have taken that position consistently. May I go back a couple of years ago to just one of the occasions we previously talked about this. Below is my contribution (not my heading)
Myna thuggery
Without saying what others should think about this, I shall offer what I think. I do not subscribe to the demonization of the C Myna. They are successful inhabitants of the built environment; it has been said they do not occur out of sight of human habitation. Most birds in the suburbs are here because they have adapted to the suburbs, some very successfully, perhaps having exploded as a result of European alteration of the wider environment (ie much of Australia), like Galahs, magpies, magpie-larks and Crested Pigeons. Goshawks and sparrowhawks also prosper in this artificial environment because of the abundance of easy targets, whether introductions or new artificial-habitat-exploiters (in particular Crested Pigeons). Of course in this suburban zoo different species that would never interact in the ('natural') wild press upon one another, hence, eg the annual cleaningout of blackbird nests by nesting P Currawongs, and screeching competition for hollows by the exotic-seed-raised abundance of hollow-nesters. See heroes, villains and victims in these interactions if you wish. I recall a BASNA seminar a few years ago where one researcher demonstrated that the Noisy Miner was a greater threat to small birds than the C Myna. I believe this has been linked to health of the woodlands. Indeed, there is a project on the south Coast aimed at reducing Bell Miner concentrations for that reason. |
Bruce Lindenmayer responded to those comments as follows:
From: Bruce Lindenmayer [m("bigpond.net.au]","blaags");">
Sent: Friday, 27 February 2009 10:04 PM
To: m("indianmynaaction.org.au","chat");">; 'Canberra Birds'
Subject: [canberrabirds] INDIAN MYNAS
The discussion on the COG chat line, in my view, has missed a few vital points and has taken the discussion in an irrelevant direction.
Dealing with the second issue first, there has been quite a bit of discussion about Indian vs Noisy Miners. Clearly, both Noisy & Bell Miners have adverse impacts on other native bird species, and several studies have demonstrated this. But why this should be related to Indian Myna threats is puzzling. We could talk about lots of other pest species in the same context!
The Indian Myna has been classified by the IUCN as one of the World's 100 Most Invasive Species and Australian National Vertebrate Pests Committee as an "Extreme Threat". Anyone who has birdwatched in Cairns, Fiji or in the leafy suburbs and urban parks in Melbourne is confronted with massive populations, which clearly have excluded almost all small native birds. In Cairns I understand, populations of between 500 & 1000 per sq km have been observed. Studies in Canberra Nature Parks in the 1990s have confirmed agressive displacement of native birds and mammals from nest hollows.
CIMAG has never pretended to have all the answers on Indian Myna threats, and we are strongly supporting the work of Chris Tidemann & Kate Grarock to ensure that the best science underpins our activities.
Bruce Lindenmayer
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Needless to say I did not agree then or now with the assertion that ïn the leafy suburbs of Melbourne “massive populations have clearly excluded almost all small native birds”. I think it is evident from the recent paper that there has been no scientific demonstration of that. I was very interested to see the results of the ‘best science’ that was to be brought to bear on the issue of impact on small birds.
Then the paper appeared, the heading of which, and part of the abstract of which, appears below.
Is It Benign or Is It a Pariah? Empirical Evidence for the Impact of the Common Myna (Acridotheres tristis) on Australian Birds
Kate Grarock1,2*, Christopher R. Tidemann1,Jeffrey Wood1, David B. Lindenmayer1,2
1 Fenner School of Environment and Society (College of Medicine, Biology and Environment), The Australian National University, Canberra, Australian Capital Territory, Australia, 2 Invasive Animals Cooperative Research Centre, University of Canberra, Australian Capital Territory, Australia
We found a negative relationship between the establishment of the Common Myna and the long-term abundance of three cavity-nesting species (Sulphur-crested Cockatoo, Crimson Rosella, Laughing Kookaburra) and eight small bird species (Striated 1Paradoxes, Rufous Whistler, Willie Wagtail, Grey Fantail, Magpie-lark, House Sparrow, Silvereye, Common Blackbird). To the best of our knowledge, this finding has never previously been demonstrated at the population level. We discuss the key elements of our success in finding empirical evidence of a species impact and the implications for prioritisation of introduced species for management. Specifically, prioritization of the Common Myna for management over other species still remains a contentious issue.
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As I have said, I cannot see in the paper the evidence for the conclusion expressed about impact on small birds. Do not take my word for it. Read the paper and make up your own mind. References that have been made to impact of Pied Currawongs are only to draw attention to one probable cause of decline in small birds that is not dealt with in the paper.
Meanwhile the paper has attracted some publicity in the general media with a lot of references to ‘most disliked species’ etc. Is it any wonder? Look at the title of the paper. I am very surprised that a scientific journal, even one ambitious to widen its readership, would choose such a title. Are ‘benign’ and ‘pariah’ the only possibilities? Are all ‘non-benign’ species pariahs? What about ‘Does the CM have any impact on numbers of small birds?’ or even ‘Has there been a decline in small birds and if so what are the main causes of this?’ - but perhaps that is not the question that the research project was designed to address.
Not a good beginning for a rational discussion about prioritising introduced species for management.
