BRITISH WARBLERS
the vicinity of Stavropol and the northern slopes, but there are no records from Trans-Caucasia. Crossing the Caspian Sea, we find it occurring in the Mangishlak Peninsula, breeding along the west of the delta of Sir Daria, and in Western Thian-Shan, visiting Iskandar Kul and the Northern Pamirs; and still continuing east, we find it on Lake Ala Kul, and finally lose sight of it on the southern slopes of the Altai Mountains. There is much to be learnt about the southern range; at present it has not been found in Egypt or Tunisia, but in winter it visits Morocco and Algeria.
Now it must be evident to any one who follows these details, and at the same time bears in mind certain habits of this bird referred to in the text, that we have in these habits a possible explanation of some of the facts which are otherwise somewhat inexplicable. Since, therefore, it is probable that at some future date a more intimate acquaintance with these habits will influence and expand our ultimate knowledge of the distribution, and in order that the relation they may bear to the present incomplete state of this knowledge may be fully realised. I propose to briefly allude to them again.
A partial and in many places almost complete cessation of the song after pairing has taken place until the young leave the nest.
A very erratic appearance in any one particular district from year to year.
Very skulking habits after eight o'clock in the morning until the evening and during incubation throughout practically the whole day.
In countries where the bird is seen in the spring and autumn migration, but is not supposed to breed, especially where the autumn migration is a comparatively early one, it is possible that an explanation may be found in the first of these habits, the bird being overlooked during the quiet period. But after due allowance is made for these habits, and the resultant unsatisfactory state of our knowledge, the geographical distribution remains an interesting one.
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