The willow-wren is a pretty little bird, although without any bright colour in its plumage, which at a short distance looks of a soft greenish yellow tint. He is best seen when the trees are opening their buds, before the thickening foliage hides his tiny, restless, flitting form from sight. He is the least shy of the warblers, his trustfulness being in strong contrast to the suspicious manner and love of concealment of the blackcap and whitethroat. He will unconcernedly continue his hunt for minute insects, and utter his melody at intervals, within a few feet of a person, sitting or standing, quietly observing him. The song, although a small one, both as to duration and power, has a singular charm: not merely the charm of association experienced in a voice long absent and heard once more--a voice of the spring, that comes before the loud call of the cuckoo and the familiar, joyous twitter of the swallow; it is in itself a beautiful sound, one of the sweetest bird-songs heard in our country. ‘A song which is unique among British birds,’ says Mr. Warde Fowler, whose description of it is, perhaps, the most perfect which we have. ‘Beginning with a high and tolerably full note, he drops it both in force and pitch in a cadence short and sweet, as though he were getting exhausted with the effort.... This cadence is often perfect; by which I mean that it descends gradually, not, of course, on the notes of our musical scale, ... but through fractions of one, or perhaps two, of our tones, and without returning upward at the end; but still more often, and especially, as I fancy, after they have been here a few weeks, they take to finishing with a note nearly as high in pitch as that with which they began.’ After this it is interesting to read Mr. J. Burroughs’s impressions of the willow-wren’s song. He writes: ‘The most melodious strain I heard, and the only one that exhibited to the full the best qualities of the American songsters, proceeded from a bird quite unknown to fame--in the British Islands, at least. I refer to the willow-warbler.... White says it has a “sweet, plaintive note,” which is but half the truth. It has a long, tender, delicious warble, not wanting in strength and volume, but eminently pure and sweet--the song of the chaffinch refined and idealised.... The song is, perhaps, in the minor key, feminine and not masculine, but it touches the heart. ‘That strain again; it had a dying fall.’ ‘The song of the willow-warbler has a dying fall; no other bird-song is so touching in this respect. It mounts up round and full, then runs down the scale, and expires upon the air in a gentle murmur.’