Thanks for the various comments on this. I suppose I should clarify two things. In this case I don’t think it fair to blame the media: newspaper or TV, for reports on this. I am not complaining about the Sydney Morning Herald showing this. They could hardly be expected to know the problems behind the study. I am not criticising the idea behind the study either.
Even though “The Project” on TV last night ran a rather trivialising segment on this and the film shown in the background again appeared to confuse between the Common Myna and Noisy Miner, flipping from one to the other in a way that would confuse many people. These are two separate but slightly paralleled problems.
The errors are not from bad reporting but bad science. My complaint was about that the GBS data was significantly misrepresented, more in the methods and interpretation, than in the results. Then the calculations done and conclusions applied are well beyond the capacity of the data. As it was me who created (not the GBS but) the GBS database and compiled all the data for the first 21 years (1316 observer years of data) and wrote up the analysis of the survey, I am uniquely placed to comment on this. For what it is worth, I bring to notice these extracts from The GBS Report (page 49 on the final section of the introductory part, before the species texts). For those unfamiliar, The GBS Report is 130 pages of detailed analysis of the survey. These advices (next two paragraphs), that I wrote in about 2000 to 2002, were not mentioned in the relevant paper and so I suspect were not considered. I believe that the GBS data were not properly taken in context. Normal process is if the authors disagree with the advice from the most relevant prior document, that is fine, but they should mention and discuss why it is that they disagree with it.
It would be wrong to interpret too much cause and effect in these data, though there are suggestions of linkages. Most obvious is that the increase in the Common Myna matches a decline in the Common Starling. Both species are likely to reach a steady state in the top ten common species (unless some action is taken). Over that time, most of the larger parrots have increased drastically, even though the Common Myna has been strongly implicated as a nest competitor.
The GBS method is designed as a monitoring tool rather than experimental science. By collating the data in structured ways, measurable conclusions can be drawn from it. Both the method and the data built up from it provide a useful system for assessing the effectiveness of any management action that may be targeted towards particular species. Lastly, the results of the GBS need to be taken in context. ………… That is the main reason why a detailed account of the overall results of the GBS was provided prior to the species description section. It also tells a fascinating story.
Philip
