BOOK REVIEW:

The Avifauna of Hong Kong

[G.J. Carey, M.L. Chalmers, D.A. Diskin, P.R. Kennerley, P.J. Leader, M.R. Leven, R.W. Lewthwaite, D.S. Melville, M. Turnbull and L. Young]

Published by the Hong Kong Bird Watching Society, 563 pp.

ISBN 962-7508-02-0, Available from the HKBWS office (tel. 2377 4387 or hkbws@hkbws.org.hk) at HK$250 for HKBWS members, and HK$350 for non-members, plus packing and postage

by Richard T. Corlett

The birds are the best-known group of organisms in Hong Kong. Not only do we have a complete species list – which is probably not true for anything else except the amphibia – but for every bird species we know the local, regional and global distribution and, for the majority of species, at least something about its ecology. I say "we", but until now most of this information has been locked away inside the heads of local birders or in the largely unpublished records of the Hong Kong Bird Watching Society. The Avifauna of Hong Kong not only makes much of this information available for the first time, but also provides a variety of analyses which will be of interest to the general ecologist.

The book starts with a useful history of ornithology in Hong Kong, from Robert Swinhoe's visit in 1860, up to 1997. This ends by noting that the membership of the HKBWS, which was dominated by expatriates until recently, is now largely local. Unfortunately, the 1997-1998 cut-off for most of the book, means that the work of expatriates still dominates the text, and the rapidly expanding research output from Hong Kong-born ornithologists is barely mentioned. After this introduction there is a brief description of the physical characteristics of Hong Kong, followed by an excellent account of the climate (by C.Y. Lam). There is then a rather odd selection of colour plates. This includes a photograph of 30-40 year-old secondary forest at Tai Po Kau described as "mature woodland", which, I suppose, makes me "over-mature"! The habitat pictures will be useful for readers unfamiliar with Hong Kong, although some major habitats are omitted, but the bird pictures are unexciting and their subjects apparently selected at random.

We then get into the meat of the book. First there is a new checklist of the bird species recorded in Hong Kong, with English and Chinese common names, the category to which each species has been assigned (from "apparently wild", via various categories for species escaped or released from captivity, to "doubtful"), and the principal status (resident, winter visitor etc.). This is followed by the results of the breeding bird survey carried out by the society between 1993 and 1996, with individual maps showing the breeding distribution (in 1 km squares) for each species. Despite the obvious limitations of such surveys, the results are fascinating and will provide an immensely valuable baseline for the future. Next come the winter waterbird counts, carried out in Deep Bay since 1979. Again there are problems with consistency, which are clearly explained, but the result is the best long-term record of any group of organisms in Hong Kong. A rather disappointing summary of the ringing data follows. More than 45,000 birds have been ringed in Hong Kong since 1975, but only 35 have been recaptured "overseas" (which includes China!) and only 19 ringed outside Hong Kong have been caught here. The only other information extracted for this section from the huge ringing effort is a wonderful list of the longest surviving ringed birds. Who would have guessed that Japanese White-eyes can live more than nine years and Chinese Bulbuls more than ten?

The last section before the species accounts concerns the wild bird trade and its impact on Hong Kong's avifauna. This is essential reading, not only because without it you cannot understand the categories used in the species list, but also because of the huge impact that "ex-captive" birds have had on local bird communities. The downgrading of several species from "natural colonist" to escaped or released captives will come as surprise to many bird watchers, and the subsequent upgrading of several of these to "re-established native species, non-natural arrival" will be controversial. However, I think the impact of releases has still been underestimated. The account of the White-rumped Munia, for instance, while noting that many early records were from Hong Kong Island, does not mention the large numbers of birds sold to Buddhists for release and treats it as a natural colonist.

Apart from a useful (but outdated) bibliography of the local bird literature, the rest of the book consists of detailed accounts of each species recorded from Hong Kong. Each account starts with a description of the range and, where relevant, taxonomy, of the species, followed by a detailed analysis of its distribution and status in Hong Kong, including any historical changes in these. Seasonal patterns of occurrence and differences between years are shown in graphs which give a quick visual image of the major patterns, although exactly what the numbers plotted mean was not at all clear to me, even after reading the section which is intended to explain this. Additional ecological information is given for some species but not others, presumably depending on the interests of the particular person who wrote each account. Anecdotal accounts of diet are sometimes included but the vast amount of published and unpublished (but easily accessible) data from faecal analysis in Hong Kong is ignored.

The main weakness of this book is that the results of the many recent ecological studies in Hong Kong, including those by co-author Michael Leven, are almost entirely omitted. In a number of places this information could have greatly improved the species accounts without significantly adding to their length. There is clearly room for a separate book on the ecology of Hong Kong birds. That said, this is a wonderful summary of the pre-1998 bird records and will be mined by birdwatchers and ecologists for decades. Could the same be done for other groups of organisms in Hong Kong?

P.26-27