( 133 ) ON THE YELLOW WAGTAILS, AND THEIR POSITION IN THE BRITISH AVIFAUNA. BY N. F. TICEHURST, F.R.C.S., M.B.O.U. IN 1832 the late John Gould pointed out that the British Yellow Wagtail was a different species from that inhabiting the nearest parts of the continent and at the same time clearly showed that, while the continental bird was of rare occurrence in this country, our common species was almost equally rare on the continent.* The common Yellow Wagtail (Motacilla rail, Bonaparte) is a regular summer migrant to the British islands, which form its head-quarters throughout the breeding season. It arrives on our south coast during the last ten days of March, throughout April and during the first week of May, the males generally appearing a full fortnight before the females. Jts breeding range extends from the southern counties of England as far west as Somerset, northward to Inverness and Aberdeen, throughout which area it is generally distributed in suitable localities. In Devon and Cornwall it occurs chiefly as a spring and autumn migrant, though in the former county it breeds in limited numbers. In Wales it is local as a breeding species, while to the north of Scotland it can only be regarded as a rare visitor. It is said to have occurred in the Shetlands, and an adult male was obtained on Fair Isle, 8th May, 1906, and in Ireland it is extremely local, breeding in one or two localities only. In most parts of the continent it occurs only as a straggler during the periods of migration, but in France it is found in summer as a breeding species to the west of " Proc. Zool.- Soc," 1832, p. 129. 134 BRITISH BIRDS. Dieppe, and occurs regularly as a migrant through Portugal and the western half of the Spanish Peninsula. In winter it is found over a large part of the continent of Africa and has even reached the Transvaal, but it is of most frequent occurrence along the west coast. The nesting habits of this bird are given more or less fully in all the text books, and are so well known to British ornithologists that there is no need to recapi­ tulate them here. On the continent of Europe our common species is replaced by one or other of the numerous forms of the Blue-headed Wagtail, the males of which all differ from the males of the Yellow Wagtail in having the head of a lighter or darker shade of bluish-grey instead of greenish- yellow, and having a white streak above the eye (absent in some of the forms) instead of a broad streak of canary- yellow. The females and young birds are less easily dis­ tinguished. These various forms are only separable from one another by the differences in shade of the colour of the head and the presence or absence of the white eye- stripe. Of these forms the following five have occurred in this country: 1. BLUE-HEADED WAGTAIL. Motacilla flava flava L. The Blue-headed Wagtail is found over the greater part of Europe, ranging from as far north as central Scandi­ navia and northern Siberia, to the shores of the Mediter­ ranean. The adult male has a bluish-slate crown, a white stripe above the eye, and nearly always an ill-defined white streak through the ear-coverts, which are darker than the crown. The female can be distinguished from that of If. raii by the slightly bluer tint of the crown and the purer whiteness of the eye-stripe and chin. The young birds in autumn are much less easy to identify with certainty, especially in the field. In the latter part of August, and from thence on till the beginning of October, when they are to be found on our coasts, the autumn moult is taking place, and being a gradual process, a good deal of variation is to be met with according to the ages of the individuals and the consequent different degree to N. F. TICEHURST : YELLOW WAGTAILS. 135 which the moult has progressed. The Wagtails as a whole, too, seem prone to a certain amount of individual variation, particularly in the distribution and intensity of colour of the lighter parts of their plumage. It is difficult, there­ fore, to lay down hard and fast distinctions between the young of the two species at this season, but from the examination of a good series the following points may be enumerated as being pretty constant throughout:—In M. raii the throat and upper breast are a warm pinkish buff, and may have some of the darker feathers of the first plumage still showing along the sides and below if the moult is not complete. Below the base of the mandible the colour is often inclined to be paler, but is never white. In M. flava flava, the throat in the majority of specimens is white, but it may be mixed with a few yellowish feathers. On the breast the white shades gradually into pinkish buff, with a good many yellow or ashy-brown feathers inter­ mingled, and so on the belly into a purer yellow, which varies in intensity enormously in individuals of both species. The eye-stripes are pinkish buff or buffish white in all the M. raii I have examined, while in the other species they are never of this colour, but vary from yellowish white to almost pure white. These characters, besides being the most constant, are useful ones in the field, as when the observer has once got them firmly fixed in his head he can be almost certain of picking out, with the help of a good glass, the young Blue- headed Wagtails in a mixed flock. The tints of the back show a great deal of variation within small limits, and are dependent on the stage to which the moult has advanced. On the whole, the head and back of M. raii are inclined to a warmer tint of brown than those of M. f. flava—almost a clove-brown on the heads of some specimens, and with a tinge of yellow if the bird is only just beginning to moult. In M. flava flava the tint is decidedly colder and a more greenish-brown, and the green of the rump seems to be more decided in most specimens. The Blue-headed Wagtail has now been recorded from most of the southern and eastern counties of England, several times from Scotland, and from Derby, Cumberland and the Shetlands, but its occurrence in Ireland is doubtful. 136 BRITISH BIRDS. As would be expected by its geographical range, it has occurred more frequently in the British Isles than any other of the following forms, and I shall give later a more detailed account of its status in this country. 2. SYKES' WAGTAIL. Motacilla flava beema Sykes. This form represents the above in western and central Siberia, and winters in Afghanistan and India. It occasionally occurs in western Europe and the countries bordering the Mediterranean during migration. It differs from M. flava flava in having a pearl-grey head and a white face and ear-coverts, with a pearl-grey band through the eye. A male of this race was obtained at Rottingdean, Sussex, on April 20th, 1898, and is now in the Tring Museum. It was recorded in the "Zoologist"* by Mr. Butterfield. The male bird that was obtained with the first Sussex nest of the Blue-headed Wagtail on 31st May, 1901, was said by Mr. Dresser to " come nearest to M. beema,"f but it could not to my mind be described as having white cheeks, and was without doubt, I consider, a somewhat worn specimen of M. flava flava. So that the only typical specimen of M.f. beema that has yet occurred in this country is the one in the Tring Museum. 3. G-REY-HEADED WAGTAIL. Motacilla flava borealis Sund. This is the race which breeds in northern Scandinavia, Russia, and Siberia. It occurs on migration throughout southern Europe, and winters in north-east Africa, India, Ceylon, and Burma. The head and nape are a dark slaty- blue ; the lores and feathers round the eye and ear-coverts darker, almost black; the sides of the neck are slaty-blue, the cheeks and chin white, and the eye-stripe is absent. Of this form, as might have been expected by its distribution, a number of specimens have now been obtained in the British Isles. Two birds that occurred on the Pentland Skerries have been assigned to it by Mr. Harvie- Brown,J the first being obtained on May 19th, 1888, while the second was seen by the same man who shot the first, on May 3rd of the following year. * " Zoologist," 1902, p. 232. t T.c, 1901, p. 389. X " A Vertebrate Fauna of the Orkney Islands," p. 108. N. F. TICEHURST: YELLOW WAGTAILS. 137 In the spring of 1901 an adult male was captured in a lark net at Halifax, and was exhibited by Mr. W. E. de Winton at the British Ornithologists' Club on May 20th, 1903* On May 13th, 1903, two adult males were shot at Willingdon, in Sussex; they were recorded in the " Zoologist," and exhibited at the British Ornithologists' Club by Mr. Butterfield on the 20th May of the same year.f Another adult male was shot near Winchelsea, Sussex, on May 2nd, 1904, and was exhibited by Mr. M. J. Nicoll at the British Ornithologists' Club on May 18th.J Lastly, a pair were obtained, with their nest and eggs, by Mr.