Cypselus apus (Linnaeus*).
THE SWIFT.
Cypselus apus.
Cypselus, Illigerf.—Bill very short, wide, triangular at its base and depressed ;
culmen and commissure much decurved ; gape extending beyond the eyes. Nostrils
longitudinal, the edges raised and furnished with small feathers. Wings,
with ten curved primaries, very long and pointed, the first a little shorter than
the second, but longer than the third. Tail, of ten feathers, somewhat deeply
forked. Tarsi very short, feathered in fro n t; toes four, all ordinarily directed
forwards, the middle and outer with three phalanges only ; claws short, large and
much curved.
T h e characters which distinguish the Swifts from the
Swallows are even on a slight examination so well marked
and so decisive that it is curious their important hearing on
* Hirundo apus, Linnaeus, Syst. Nat. Ed. 12, i. p. 344 (1766).
t Prodr. Syst. Mamm. et Av. p. 229 (1811).
classification was not sooner recognized. Though so like
Swallows in much of their external appearance and in many
of their habits, Swifts have scarcely any part of their
structure which is not formed on a different plan; and, instead
of any near affinity existing between the two groups,
it can scarcely be doubted by an unprejudiced person that
the Cypselidce not only differ far more from the Hirundinidce
than these do from any other Family of Passeres, but that
they belong to what, in the present state of ornithology,
must be deemed a distinct Order of Birds—and they are
here included among the Picarice, as before (page 267) indicated.
In deference -to the practice of British zoologists,
who have been so long accustomed to regard the Swallows
and Swifts as members of the same Family, it seems expedient
in this work to place the latter next to the former, but
it must be understood that they really have no relationship
therewith, and that in fact, except a somewhat remote connexion
with the Caprimulgidce, the only true allies of the
Cypselidce are the Trochilidce, or Humming-Birds, with
which they form a groUp that has received from Nitzsch the
name of Macrochires.
The Swift comes to us from Africa, arriving sometimes
soon after the middle but more commonly towards the end of
April, or even not till the beginning of May, the variation in
the time of its appearance being possibly due to the state of
the season in the countries whence it takes its departure
or over which it passes on its way. Its stay in the British
Islands is comparatively short, most of the birds which
breed or are reared here generally leaving their home with
great punctuality very early in August, though stray examples,
and sometimes considerable companies, not unfrequently
make their appearance during the next two months. Mr.
Blackwall saw a Swift October 20th, 1815, Mr. C. Bowring
sent the Author word of one seen by him near Conway, October
31st, 1855, while Mr. W. Adam records (Mag. Nat. Hist. viii.
p. 513) one that he saw in Perthshire, November 8th, 1834,
and Mr. Cornish is reported to have seen one in Devonshire,
November 27th, 1835.