TWENTY years ago, when the Birds of Europe was nearing its end, I thought of issuing a similar work on the Birds of Northern Asia, in order to furnish a complete account' of the Ornithology of the Palaearctic Region. It seemed, however, that I could not expect to obtain for my project the support of a sufficient number of subscribers to save me from serious pecuniary loss, and with much regret the project had to be abandoned. I have since been urged by many friends to bring out a Handbook of European Birds, of a size, and at a price, which would be convenient to travellers and field-naturalists—the latter being a class of persons with whom, for the sake of old associations, when I counted myself one of them, I have still the greatest sympathy. Bearing in mind, however, my former desire to treat of the Birds of Northern Asia, and knowing how non-existent is any physical barrier between the Eastern and Western portions of the Palaearctic area, I have thought it expedient not to limit the present Manual to European species, even with the addition of those of Barbary and the Atlantic Islands (Madeira, Canaries, and Azores).
There is admittedly little difficulty in laying down the southern frontier of this area in Africa, since the Great Desert forms a natural boundary, but the southern limits in Asia are less easily defined. I suppose these to run to the northward of the Arabian Desert, and including the tableland of Persia, the highlands of Baluchistan, the whole of Afghanistan, and the Himalayan Range above about 6,000 feet, stretching to the south of Tibet, and north of the valley of Yang-tse-kiang as far as the Pacific, and then round Corea and the main islands of Japan, with of course all the countries lying to the northward of a line so indicated, but it seems to be admitted that these limits cannot at present be more definitely drawn.
This work being primarily intended for the use of field-naturalists and travellers, I have thought it advisable to cut as short as possible all technical questions, such as synonymy and the like. The arrangement followed is very nearly the same as adopted in the Birds of Europe, with of course the additions rendered necessary by the larger ground that has to be covered. It will be seen, however, that the extreme sub¬division of genera, species, and subspecies now so much in fashion has been avoided, and this, I think, will be found a practical convenience to the field-worker. The endless manu¬facture of subspecies in particular, often based on very trifling differences of tint, seems calculated rather to puzzle and dis¬courage than to assist the beginner, for even the expert is apt to find himself lost in investigating slight distinctions which are occasionally not much more than those which separate individuals. No one can doubt that in most cases the wider the area over which a species ranges, the greater is the amount of variation to be found among its members, the variation being apparently due to climatic or other local causes. When fairly defined limits can be assigned to such variations, it is quite legitimate to accord them separate treatment, whether they be called subspecies or not ; but when every intermediate stage between examples that are most unlike can be found, the attempt to differentiate them more than Nature herself has done seems entirely inexpedient. For this reason, besides being in principle a binomialist, I have declined the recognition of such so-called “subspecies,” as those who have described them have so little confidence in as to need the aid of trinomials.
The descriptions of the various species have been mainly taken from specimens which were then in my own collection, now in the Museum of Owens College at Manchester, but some are from specimens in the British Museum or that of Tring, which last have been generously placed at my disposal by their possessor, the Hon. Walter Rothschild, M.P. In most cases I have examined as large a series of specimens as possible, but there are some few of which I have not been able to see a single example, and have then been compelled to borrow a published description.
It had been my intention to include a map of the Palaearctic area, but consideration showed that it was impossible to give one in an 8vo. volume which would be of any practical use to the reader. A second plate from a drawing by the late Mr. Joseph Wolf, has therefore been substituted which, I think, can scarcely fail to give pleasure to those who may possess the work.
I take this opportunity of returning my thanks to many friends both at home and abroad, who have kindly assisted me in preparing this work, and among them I would especially name Professor Newton, who has helped to look over the proofs, and in various other ways has greatly assisted me; Mr. Howard Saunders, on whose co-operation I could always reckon; and lastly to the Society for the Protection of Birds, who permitted me to publish the work at No. 3, Hanover Square.
H. E. DRESSER.
28, QUEENSBOROUGH TERRACE, W.
1st June, 1903.