The Willow Warbler is much more generally distributed than the last-named bird; but it is possible that it is considered commoner from the difference in the haunts of the two species—the Wood Warbler, as already remarked, keeping further away from habitations. As a rule, the Willow Wren arrives in this country about the end of the first week in April—that is to say, before the Wood Warbler, but not so early as the Chiff-chaff, which is the first of the genus to appear.

Yarrell speaks of these birds as “having acquired with us the general name of Willow Warblers, or Willow Wrens, from their prevailing green colour;” but Thompson, in his “Birds of Ireland” (i. p. 192), says, “this name was doubtless bestowed upon the bird originally on account of its partiality to willows, which I have frequently remarked, the twigs and branches of the common osier (Salix viminalis) abounding with aphides, being on such occasions its chief favourite.” There is yet another suggestion—i. e., that the name may have been bestowed from the circumstance that these little birds make their appearance just as the willow is budding.

It is marvellous how these tiny creatures can sustain the protracted flights which are necessary to transport them from their winter to their summer quarters; and yet that they make these long journeys is well ascertained. On the 23rd of April a Willow Wren came on board a vessel eighty miles from Malta and fifty from Cape Passaro, the nearest land. Two days later another alighted on the rigging sixty miles from Calabria, and one hundred and thirty-five from Mount Etna. On the 26th of April, eighty miles from Zante and one hundred and thirty from Navarino, a Willow Wren and a Chiff-chaff were found dead on board, presumably from exhaustion, as they were apparently uninjured. Many other such instances are on record.

The present species may be regarded as the commonest of the three which visit us, being generally dispersed in favourable localities over the whole of Great Britain and Ireland. Although it has not been met with in the Hebrides, the Willow Wren has occasionally been seen in Orkney, and the late Dr. Saxby has recorded a single instance of its occurrence in Shetland. Through every country in Europe it seems to be well known as a periodical migrant.

The winter quarters of the Willow Wren are to a certain extent those of its congeners, that is to say, Northern Africa and Palestine, where it is very numerous in the cold season, but it has been found much further southward. Mr. Ayres sent a specimen to Mr. Gurney from Natal; the late Mr. Andersson met with it in Damaraland, S.W. Africa; and Mr. Layard some years since procured specimens at the Cape. As is often the case with allied species, the remarks as to habits and food which have been applied to the Wood Warbler will apply almost equally well to the present species. The distinction between the birds themselves has been already pointed out. The nests of the Willow Wren and Chiff-chaff are both lined with feathers, the eggs of the former being white spotted with red; while those of the latter are white spotted with purple, chiefly at the larger end.

Varieties in this group of birds are rarely met with, and it may therefore be worth notice that in May, 1861, a primrose-coloured Willow Wren was shot at Witley Park, in the parish of Witley, Surrey, and forwarded for inspection to the editor of “The Field.”