Falco peregrinus, Gm.
8. :- Jerdon's Birds of India, Vol. I, p. 21; Butler, Guzerat; Stray Feathers, Vol. III, p. 442; Deccan and South Mahratta country; Stray Feathers, Vol. IX, p. 370 ; Murray's Vertebrate Zoology of Sind, p. 65 ; Hume's Scrap Book, p. 49.
THE PEREGRINE FALCON. Bhyri, HIN.
Length, 18 to 20.25 ; expanse, 35 to 39; wing, 13 to 14.5 ; tail, 6 to 6.75 ; tarsus, 2 to 2.2 ; bill from gape, 1.3.
Length, 16; wing, 12.25 ; tail, 5.75.
Bill, pale blue at base of upper mandible, greenish at base of lower mandible, bluish-black at tips of both; cere dingy-yellowish ; irides deep brown; legs and feet pale yellowish-brown ; claws black.
Adult : above deep bluish-grey, most of the feathers with some dark markings; head, nape, and moustache darker ; rump and upper tail-coverts much lighter; wings blackish-brown, more or less spotted or barred with white on the inner web ; tail grey, with some dark bands, and a pale tip ; beneath chin and throat pure white ; breast, white, with a few narrow longitudinal streaks, almost disappearing in old individuals; abdomen with some small heart-shaped spots; flanks and thigh-coverts with dark transverse bars; inner wing-coverts white, with numerous well-marked dark cross bars.
Young bird: above dark brown, most of the feathers edged with paler and somewhat rufous brown; head more edged with whitish, especially the hind head ; cheek-stripe brown; wings darker brown than the back, with pale rufous spots or bars on the inner webs ; the tail dusky-cinereous, with numerous interrupted pale rufous or rufous-white bars ; beneath white or creamy, with brown oval spots, longitudinal and narrow on the throat and breast, wider and ovate on the abdomen.
The following extract from Mr. Hume's " Rough Notes" will assist in discriminating the various species of Falcons : :-
" First, the Sacer so far exceeds all the others in size that this alone would be sufficient to identify it. The wings average from 15 to 16 inches, against 14 in F. juggur and F. peregrinus, and 13 in perigrinator and babylonicus. Then, while the central tail-feathers of peregrinus, perigrinator, and babylonicus are all barred, (in different stages according to age) and those of juggur are unbarred, those of Sacer, in most of the specimens I have seen, are marked with roundish spots (more or less broad ovals on the laterals). Then, again, the Sacer never has much, and commonly shows scarcely any sign of a cheek-stripe, while in all the others it is well marked. Further, the Peregrine is distinguished at all times from the Juggur, by its huge, broad cheek-patch, which in the Laggar is at most about a quarter of an inch broad, and by the entire absence of barring on the centre tail-feathers in F. juggur, which absence equally distinguishes this later from both perigrinator and babylonicus.
From babylonicus, both perigrinator and peregrinus differ in the cheek-stripe, which is narrow in the former, as in the juggur, but very broad and strongly marked in the two latter; but babylonicus, as far as my experience goes, is not of the juggur type of brown plumage, the old birds becoming slaty or greenish-blue as do both peregrinus and perigrinator, whilst the oldest juggur is never more than slaty-brown.
Then, as to perigrinator and peregrinus, the comparatively rich rufous coloring at all ages of the under parts, and the very dark head and nape of the former, at once separate the two species.
The Peregrine, though it occurs throughout the district, is nowhere common. It is also called the Duck-hawk, from its habit of preying on the duck tribe; so long as they (the ducks) remain on the water, they are safe, and the ducks seem instinct lively to know this, for immediately a Peregrine appears in sight, they betake themselves to the water with the utmost speed they are capable of, the hindmost generally falling a victim to the Peregrine's superior powers of flight.
Nothing certain appears to be known concerning its nidification in this country, but it is strongly suspected to breed on the banks Of the Cabool and Swat rivers. I have myself seen young birds offered for sale at Kotri, Sind: these birds were said to have been obtained from nests on the banks of the Indus.