Here again our ignorance comes in and our story must end. Observers have sat up in vain till two or three in the morning, awaiting their return. Not one has reappeared, and yet the next day they will all be seen back again, apparently unwearied by their restless night, but rather enjoying to the full the marvellous powers of flight which they have inherited.
The sexes and young are alike in plumage and are of a uniformly dark sooty brown, the chin and throat being dull white. The tail is short and slightly forked; wings very long and narrow. The feet are extremely feeble, the four toes all directed forward and having sharp, recurved nails, which enable them to cling to perpendicular surfaces. Length 6·5 in.; wing 6·8 in. It is generally abundantly distributed throughout our islands, but becomes scarcer in the North. It winters in Africa.
[Illustration: COMMON SWIFT _Cypselus apus_]
This is a much larger species than our common Swift and has only visited these islands on very rare occasions, almost all the examples obtained having been taken in the south of England. It breeds in the high mountain ranges of Central and Southern Europe, and winters in Africa. From our common species it may be distinguished by its larger size, browner colour, and light under parts. Length 8 in.; wing 8·45 in.
Another species, the Needle-tailed Swift (_Acanthyllis caudacuta_) has occurred on two occasions in England. It breeds in Central Asia, migrating in winter to Australia, and except for these two instances is unrecorded from Europe.
THE NIGHTJAR Caprimulgus europæus (Linnæus)
Arriving, the latest of all our migrants, towards the middle of May, and leaving again early in September, this strange bird is but little known to the majority of people, although by no means uncommon in suitable localities.
Its favourite haunts are gorse commons, and moorlands on the edge of woods, especially where bracken grows freely, and in such situations it may be found throughout our islands. The best time to see it is at dusk, when it comes out to capture moths, beetles, and other crepuscular insects which form its chief sustenance. Its flight is silent and very bat-like, twisting and turning with great ease and agility, now and again striking its wings together with a loud clap and uttering at the same time a sharp little whistle. When resting on a branch, which it invariably does lengthways, a curious reeling note or vibrating "churr" is uttered.