Hi Laurie,
It depends how you define your survey. The short answer is obviously you need to define your methods and keep to them, not decide which species are and are not before the event, otherwise the survey is meaningless. Thus it is I think irrelevant to ask if Tawny Frogmouths are garden birds, but that about Boobooks and Powerful Owls may not be, even though they are much less common and in marginal habitat. It depends on what fits the rules of the survey. As for migrants, of course they should be included. Certainly in Canberra, broadly speaking about a third of species are more common in summer, about a third of species are more common in winter and the rest not so obviously consistently different.
My book: as in The third edition of my report, entitled: “Canberra Birds: A Report on the first 21 years of the Garden Bird Survey” goes into great detail about this particular survey and the methods used for it. It is 130 pages. The report is based on the first 21 years of continuous data, from 53244 observer weeks of data, from 1316 observer years of data, from a total of 294 sites. It also has a detailed discussion of the literature of urban bird surveys around the world (three pages). It is a very useful reference for anyone who has ever participated in or planned a long-term volunteer based bird population survey.
Philip Veerman 24 Castley Circuit Kambah ACT 2902
02 – 62314041
