Asian birds on the brink: 1from OBC Bulletin 34, December 2001: N. J. Collar, chief editor of Threatened birds of Asia - the BirdLife International Red Data Book gives some background to the project. Since the early 1960s BirdLife International (formerly the International Council for Bird Preservation) has had the formal responsibility, conferred by IUCN-The World Conservation Union, for preparing and publishing the global Red Data Books which identify and document the world's threatened birds (these then feed into the IUCN Red List, which evaluates all species against numerical criteria for endangerment). In April 1981, when I took up the job of compiler of the bird RDB, ICBP's Executive Committee had decreed that the work should proceed geographically, beginning with Africa; and after Africa in 1985 it was decided to do the Americas, which took me through until 1992. This was, of course, deeply unfair to Asia. My most immediate but admittedly token attempt to compensate was to pick what seemed to be Asia's most threatened species and document it, in the hope that this might help matters. The result was the review paper on Gurney's Pitta Pitta gurneyi in Forktail 1: 29-51, written with Phil Round and David Wells, which helped confirm Phil in his long-held suspicion that the mysterious creature was a level-lowland forest dweller. In this sense it did intensify the focus and accelerate the search, resulting as we all now know in the great rediscovery-not a moment too soon-of May 1986, a few weeks before the paper itself appeared. (I continue to hold this up as evidence that Red Data Books really can make a contribution to species conservation; but sadly the international bird RDB programme is the only one that survives today.)
The second and more considered attempt to compensate Asia (and indeed the rest of the undocumented species of the world) was to write, with Paul Andrew, a stop-gap annotated 'red list'. This book, Birds to watch, which appeared in early 1988, greatly expanded the number of birds formally listed as at risk in Asia, and gave the still very young Oriental Bird Club a clear focus in its conservation giving and in its reporting of records. Where the late 1970s RDB, compiled by Warren King, had treated a mere 52 Asian species as threatened (18 of them pheasants!), ten years on Birds to watch identified 286, five-and-a-half times as many. (One of the crucial immediate results of this was the establishment of the BirdLife Indonesia Programme, since Indonesia had suddenly leapt to the top of the table of countries with the most threatened birds, a position previously held by Brazil.) In 1994 Birds to watch 2 repeated the analysis, and in 2000 - with rather more detail and infinitely more pizzazz - Threatened birds of the world carried the species and categorisations that had been determined by the editors of the then almost complete Threatened birds of Asia. Nevertheless, the deep review of each Asian threatened species remained a gap that desperately needed filling. Detailed documentation greatly increases the confidence with which a team of compilers can determine whether a species is truly threatened or not. The nature of the problem can partly be gauged from this table of the changing status of threatened birds in Asia.
The figures clearly suggest that the numbers of species in the region reckoned to be in danger have been stabilising over the past decade, and to a degree this is true, but internally there are still quite a number of adjustments taking place as species exit and enter the lists. Of the strigid owls, for example, 12 were listed in 1994 and nine in 2001, but only six of these are common to the two lists. Moreover, because the passerine totals for 1988 (113) and 2001 (114) are virtually identical, the species involved might also be assumed to be very similar; but in reality the lists are amazingly different, sharing between them as few as 70 species, which is a mere 45% of the 157 (70+43+44) present on both. It is not that the earlier analyses were substandard-rather it is that new descriptions, new taxonomic treatments, new circumstances and new information have combined down the years to create this retrospectively high degree of instability; but above all it has been the patient and exhaustive assembly and evaluation of all the information, from the literature, museum skins and personal witness, that has now, I believe, brought a new level of certainty to the current list. To cope with species which just failed to qualify as threatened in the Africa RDB, Simon Stuart and I invented the category 'Near Threatened', and this has now been formally adopted by the IUCN Red List programme. The great majority of the species that have, over the years, fallen out of the earlier lists are to be found in this category, which is perhaps further evidence that the earlier evaluations were not so very inaccurate. Threatened birds of Asia provides paragraphs on 317 such species, and the addition of these and 24 Data Deficient species to the 323 threatened species means that in total no fewer than 664 species of bird in Asia are now considered cause for global conservation concern. This is one quarter of the Asian avifauna. The global totals for threatened, Near Threatened and Data Deficient are 1,186, 727 and 79 respectively; and on this basis Asia contains precisely one-third (664/1,992) of all bird species of global conservation concern. Discounting the 1970s analysis, which obviously under-researched and under-represented the situation in Asia, the proportion of threatened non-passerines in the Asian avifauna has been growing over time (60% in 1988, 61% in 1994, 65% in 2001). This begins to tell us something interesting, because if we look at the situation outside Asia we find there are 421 non-passerines out of a total of 863 bird species, which is fractionally under 50% and far closer to expected, given that non-passerines form 40% of the global avifauna. A reasonable explanation of this is that the larger, more widespread birds (as the 'non-near-passerines' in particular tend to be) are significantly more at risk in Asia than elsewhere, a circumstance attributable to two pressures: exploitation, and landscape conversion on such a scale that even relatively well distributed and extensive habitats (particularly lowland forest and both inland and coastal wetlands) are no longer sanctuary to the largest and widest-ranging species. Indeed, perhaps the most telling statistic is that Asia possesses over 60% of globally threatened species with ranges greater than 50,000 km2. This to me is a clear message that it simply does not pay to be a large bird in a region which holds over 50% of the world's human population.
And so it is that we find two pelicans, four herons, five storks, three ibises, one spoonbill, 11 waterfowl and six cranes in the book, representing high proportions of the region's big, wide-ranging wetland animals. Typically these are species which, in primordial times (by which I mean before man had worked out how to shoot an arrow), must have occurred in enormous numbers, but which have steadily been depleted to their current levels of a few hundreds or a few thousands, both by relentless hunting pressure and by ever-intensifying habitat erosion. We also, for the same reasons, find three large open-country eagles with enormous ranges (Pallas's Fish-eagle Haliaeetus leucoryphus, Great Spotted Eagle Aquila clanga and Imperial Eagle A. imperialis) and the heavyweight Great Bustard Otis tarda, whose world record for the threatened bird with the broadest longitudinal span has proved no guarantee against the ubiquitous iniquities of mankind. |
