The present volume is the first of the series of the new edition of the 'Avifauna of British India,' and, funds permitting, it is proposed to bring out about one volume every two years until the work is completed.
It has been my endeavour in writing this volume to disturb as little as possible the classification adopted by Oates in the first edition but during the thirty-two years that have elapsed since his first volume was published, much scientific work has been done and many discoveries made which have "rendered alterations imperative; some of these, unfortunately, are of a drastic nature.
In the first place, the trinomial system has been adopted a decision which has added very greatly to the number of birds to be described, i.e. to the total number of species and subspecies, though, on the other hand, it has reduced the number of species, for it has relegated to their proper positions as subspecies or geographical races many forms which have hitherto improperly held the status of species.
In using the trinomial system I have adhered to the following rules:—
Forms, or groups of forms, have been named as specific when there are no forms known which directly connect them with other forms or groups of forms.
Subspecies or geographical forms have been recognized when they differ in degree either in size, colour or some other characteristic from the forms with which they are most closely connected, yet, though linked with these forms by others which are intermediate, are themselves constant within some given area. It is true that a few island forms may not come very exactly under this definition, but in these cases the differences are such as are obviously parallel to those obtaining in non-isolated areas on the mainland. Where evolution and isolation have evolved forms which are definitely divided from all others by some characteristic which is not one merely of degree, I have treated them as distinct species.
In India we are constantly meeting with the most intricate cases of sub-specific variation, and a study of birds which admits the recognition of these geographical races and the wisdom of naming them affords infinitely greater interest both to the field and to the scientific worker than does the easier method of lumping them all together. For instance, to take two of our most common birds, the Indian House-Crow and the Red-vented Bulbul. Two species of the former and many of the latter have been recognized and given specific names, although the differences between them are in no way specific and are not any greater than the differences which exist in many other forms which have been left undivided.
The second point to which reference must be made is the unfortunate necessity which has arisen for very numerous corrections in Oates' nomenclature. Such corrections cannot but be a source of some difficulty to the older race of field naturalists, and students who have learnt these names will now have to learn those which replace them. The younger generation will, however, have the satisfaction of knowing that they are learning names which, with few exceptions, will be permanent; for,with strict adherence to the laws of priority, a time will soon come when we shall really have arrived at the bed-rock of nomenclatorial research. It should be mentioned here that I have had the unstinted help of Mr. Tom Iredale in this particular branch of the work, and his unrivalled knowledge of bibliography and nomenclature has been of inestimable help to me.
Another difference between this and the preceding edition will also be noted. With the approval of the editor, Sir Arthur E. Shipley, the synonymy has been reduced to "references to the original description and to the Blanford and Oates* edition of this work, in the former case the type-locality being given in brackets after the reference. The saving of space thus obtained and the use of briefer descriptions has given additional room for field notes, which it is hoped vi ill add to the value of the work both for field naturalists and the non-scientific lover of birds, for whom they are principally written.
As regards the classification, this is founded mainly on Gadow's work, but I have also had the valuable assistance of W. P. Pycraft, and the results of his personal work will be found in almost every order, family and genus. I must, however, take upon my own shoulders any criticisms which may be made on the minor divisions in the Passeres, though, here again, my constant object has been to disturb as little as possible the careful work of Blanford and Oates.
Ornithological work in India has hitherto been divisible into very definite periods. The first period was that prior to the publication of Jerdon's 'Birds of India' in 1862 and the subsequent eight or ten years when the leading figures were Jerdon himself, Hodgson and Blyth, who may be considered the fathers of Indian Ornithology.
An account of the chief writers on Indian birds up to 1862 was given by Jerdon in the Introduction to the first volume of the 'Birds of India.' The principal authors mentioned were Franklin, Tickell, Sykes, McClelland, Burgess. Adams, Tytler, Kelaart, Layard and Hutton, in addition to the three already mentioned.
The next period, from about 1872 to 1898, may be termed Hume's period, the other most notable workers being Tweeddale, Wardlaw-Ramsay, Biddulph, Anderson, Elwes, Beavan, Scully, Sharpe, Stoliczka, Godwin-Austen, Brooks, Ball, King, Vidal, McMaster, Blanford, Legge, Oates and Barnes, with many other minor writers.
" The third period is that of Blanford and Oates, both leading Ornithologists in the preceding period but completely dominating the position on the publication of the 'Avifauna of British India.' Since these volumes saw the light no big work has been published on Indian birds but Harington's * Birds of Burma,' Oates' 'Game-Birds of India,' many popular works by Dewar, Finn and others, and the present writer's different works on Indian Ducks, Pigeons and Game-Birds have appeared. Tn addition to these the 'Journal of the Bombay Natural History Society' contains a mass of details on field ornithology by Harington, Osmaston, Davidson, Bell, Barnes, Inglis, Bailey, Whistler, Jones, Hopwood, Mackenzie, Ticehurst, Donald and others. There are many local catalogues, and, finally, Harington's work on the Timaliidae in which the writer had the pleasure of co-operating.
Anatomy has not been treated at the length it deserves, but those who intend to take up this much neglected but most important branch of ornithology should refer to the well-known works of Dr. Hans Gadow, Huxley, Garrod, Bronn, Furbringer, Forbes, Nitzsch and Parker, and to the more recent writers such as Pycraft, Beddard and Lucas.
The would-be Ornithologist in India must also remember that it is not only the dry skins of birds which are required by the systematist who, the ugh he may have the good fortune to work in big museums and other centres where masses of material are available for comparison and where good libraries are at hand for reference, yet urgently needs specimens, especially of the rarer forms in. spirit, not only for anatomical purposes but for the study of Pterylosis etc. Again, poor skins of moulting birds are often more valuable than those in the finest condition of plumage, while the nestlings and young of many of the most common birds are still desiderata in the British Museum and other institutions.
As regards nidification, it will be seen that I have devoted considerable space and detail to this portion of a bird's life-history. It is true that birds cannot be classified according to the eggs they produce, but at the same time it is equally true that a bird's egg may be a valuable clue to show us where we should expect to find its nearest allies or, on the other hand, may cause us to suspect that it should be removed from amongst those with which it is now placed.
E. C. STUART BAKER.
4th February, 1922,