_Pandion_, SAVIGN. 1809. (Type, _Falco Haliætus_, LINN.)
_Triorchis_, LEACH, 1816. (Same type.)
_Balbusardus_, FLEMING, 1828. (Same type.)
GEN. CHAR. Bill inflated, the cere depressed below the arched culmen;
end of bill much developed, forming a strong, pendent hook. Anterior
edge of nostril touching edge of the cere. Whole of tarsus and toes
(except terminal joint) covered with rough, somewhat imbricated,
projecting scales. Outer toe versatile; all the claws of equal length.
In their shape, also, they are peculiar; they contract in thickness to
their lower side, where they are much narrower than on top, as well
as perfectly smooth and rounded; the middle claw has the usual sharp
lateral ridge, but it is not very distinct. All the toes perfectly free.
Tibiæ not plumed, but covered compactly with short feathers, these
reaching down the front of the tarsus below the knee, and terminating in
an angle. Primary coverts hard, stiff, and acuminate, almost as much so
as the quills themselves; third quill longest; first longer than fifth;
second, third, and fourth sinuated on outer webs; outer three deeply
emarginated, the fourth sinuated, on inner webs.
Of this remarkable genus, there appears to be but a single species,
which is almost completely cosmopolitan in its habitat. As in the case
of the Peregrine Falcon and Barn Owl, different geographical regions
have each a peculiar race, modified by some climatic or local influence.
These races, however, are not well marked, and are consequently only
definable with great difficulty.
Species and Races.
=P. haliætus.= Wing, 15.20–21.50; tail, 7.00–11.11; culmen, 1.20–1.40;
tarsus, 2.00–2.15; middle toe, 1.60–2.00. Second or third quills
longest. Above clear dark grayish-brown, inclining to brownish-black,
plain, or variegated with white. Tail brownish-gray (the inner webs
almost entirely white), narrowly tipped with white, and crossed by
about six or seven nearly equal bands of dusky-black. Head, neck, and
entire lower parts, snowy-white; the breast with or without brown
spots or wash. A dusky stripe on side of head (from lores across the
ear-coverts), and top of head more or less spotted, or streaked, with
the same. _Adult._ Upper parts plain. _Young._ Feathers of the upper
parts bordered terminally with white. Sexes alike (?).
Wing, 17.00–20.50; tail, 7.00–10.00; culmen, 1.20–1.45; tarsus,
1.95–3.15; middle toe, 1.50–1.90. Second or third quills longest (in
eighteen specimens from Europe and Asia). First longer than fifth.
Breast always (?) spotted with brownish, or uniformly so; top of
head with the black streaks usually predominating. Tail with six
to seven narrow black bands, continuous across both webs. _Hab._
Northern Hemisphere of the Old World …
var. _haliætus_.[68]
Wing, 17.50–21.50; tail, 8.70–10.50; culmen, 1.25–1.40; tarsus,
2.00–2.40; middle toe, 1.70–2.00. Second and third quill longest.
Breast often entirely without spots; top of head and nape usually
with dark streaks predominating. Tail with six to seven narrow black
bands, continuous across both webs. _Hab._ Northern Hemisphere of
the New World …
var. “_carolinensis_.”
Wing, 17.50–19.50; tail, 9.00–10.00; culmen, 1.25–1.40; tarsus,
2.10; middle toe, 1.70–1.95. Third quill longest, but second
just perceptibly shorter (eight specimens, including Gould’s
types). Breast with the markings sometimes (in two out of the
eight examples) reduced to sparse shaft-streaks, but never (?)
entirely immaculate. Top of the head with the white streaks usually
predominating, sometimes (in three out of the eight specimens)
immaculate white (the occiput, however, always with a few streaks).
Tail with six to seven white bands on the inner webs, which
(according to Kaup) do not touch the shaft. _Hab._ Australia …
var. “_leucocephalus_.”[69]
Pandion haliætus, var. carolinensis (GMEL.).