Chapter VI: Appendix: I. Additions and Corrections 499 (6)

=A.= Scapular process of the coracoid produced forward so as to meet
the clavicle[42] (HUXLEY). Nasal bones almost completely ossified,
the nostril being a small, usually circular opening, with a raised
or “rimmed” margin, and conspicuous, usually central, bony tubercle.
Inferior surface of the supermaxillary bone with a prominent median
angular ridge. Superciliary process of the lachrymal consisting of a
single piece. (_Falconinæ._[43])

=B.= Scapular process of the coracoid not produced forward so as
to meet the clavicle (HUXLEY). Nasal bones incompletely ossified,
the nostrils being very large, and without bony rim or tubercle.
Inferior surface of the supramaxillary bone without a median ridge.
Superciliary process of the lachrymal variable. (_Accipitrinæ._)

_a._ Superciliary process of the lachrymal composed of a single,
excessively abbreviated piece;[44] posterior margin of the sternum
with a pair of indentations, and without foramina. (_Pandion_ and
_Nauclerus_.)

_b._ Superciliary process of the lachrymal double, or composed
of two pieces, joined by a cartilaginous “hinge,” and reaching
nearly across the orbit. Posterior margin of the sternum without
indentations, and usually with a pair of foramina. (All except
_Pandion_ and _Nauclerus_.)

† Septum of the orbits and nostrils incompletely ossified (the
former always and the latter usually) and with foramina; posterior
margin of the sternum most produced backwards laterally, and
incompletely ossified, there being usually a pair of foramina.
Intestinal canal short, broad, with the duodenum simple, forming a
single loop (MCGILLVRAY). A well-developed “web” between the outer
and middle toes. (All but _Haliætus_.)

†† Septum of the orbits and nostrils completely ossified, and
without any trace of foramina; posterior margin of the sternum
produced medially into a convex lobe, and without any trace of
foramina. Intestinal canal extremely elongated, attenuated, with
the duodenum arranged in several convolutions (MCGILLVRAY). No
trace of a web between outer and middle toes. (_Haliætus._)

SUBFAMILY FALCONINÆ.

GENUS FALCO, AUCT.

GEN. CHAR. Bill strong, its breadth at the base equalling or exceeding its height; upper outline of cere on a level with, or rather lower than, the base of the culmen; gonys much arched, the chord of the arch equalling about half that of the culmen. Near the tip of the upper mandible is a prominent tooth on the commissure, and near the end of the lower mandible, which is truncated, is a deep notch corresponding; the end of the upper mandible is compressed, giving the situation of the tooth an inflated appearance when viewed from above. Nostrils circular, with a conspicuous central tubercle. Orbital region bare; projecting superciliary shield conspicuous, arched, but not very prominent. Tail shorter than wing, the feathers hard and stiff. Primaries very strong, elongated, tapering rapidly toward their points; only the first or first and second with their inner webs emarginated, the cutting being angular, and near the end of the quill. Tarsus never with a single series of transverse scutellæ either in front or behind; middle toe very long.

Subgenera.

One primary only with inner web emarginated; first to second longest;
first longer than fourth.

Tarsus longer than middle toe, and feathered far below the knee;
first quill shorter than third. Coloration of the sexes alike; old
and young slightly different in pattern and tints. Size large …

_Hierofalco._

Tarsus not longer than middle toe, and scarcely feathered below the
knee; first quill equal to or longer than the third. Coloration of
the sexes alike; old and young very different in pattern and tints.
Size, very small to large …

_Falco._

Two primaries with inner webs emarginated; second to third longest;
first shorter than fourth.

Basal joint of toes without transverse scutellæ; tarsus about equal
to middle toe.

Coloration of the sexes in adult plumage very different in tints;
in the young alike, the young ♂ resembling the adult ♀. Size
small …

_Æsalon._

Basal joint of toes with transverse scutellæ; tarsus longer than
middle toe.

Coloration of the sexes very different, in pattern and tints, at
all ages; old and young alike. Scutellæ of the toes and tarsus
interrupted at the digito-tarsal joint; tarsus much longer than
middle toe. Bill small, the cere on top less than one fourth the
culmen. Size small …

_Tinnunculus._

Coloration of the sexes alike at all ages; old and young slightly
different in pattern and tints. Scutellæ of tarsus and toes
uninterrupted from “knees” to claws; tarsus but little longer
than middle toe. Bill large, the cere on top about one third the
culmen. Size medium; form very slender …

_Rhynchofalco._

SUBGENUS HIEROFALCO, CUVIER.

_Hierofalco_, CUVIER, 1817. (Type, _Falco gyrfalco_, LINN.)
_Jerafalco_, BOIE, 1822; KAUP, 1851. (Same type.)
_Gennaia_, KAUP, 1847. (Type, _Falco jugger_, GRAY.)

Species and Races.

=1.= =F. gyrfalco.= Wing, 13.00–17.00; tail, 8.50–11.50; culmen,
.85–1.05; tarsus, 2.10–3.00; middle toe, 1.80–2.25.[45] Ground-color
varying from entirely pure white to wholly dusky, but generally bluish
(in adult) or grayish-brown (in young) above, and white beneath.
_Adult._ All the markings transverse.[46] No lighter nuchal band.
_Young._ Markings of the lower surface longitudinal, the upper parts
without transverse bars (except on the tail[47]).

_a._ Lower parts with white predominating, or wholly white.

Lower tail-coverts never with markings. No tinge of blue anywhere
on the plumage, the ground-color of which is entirely pure white
at all ages.

1. _Adult._ Upper parts, excepting head and neck, with
transverse crescentic bars of dark plumbeous; lower parts
immaculate, or else without well-defined markings. _Young._
Upper parts with longitudinal stripes of dark plumbeous; lower
parts usually conspicuously striped. _Hab._ Greenland (in the
breeding-season); in winter, occasionally wandering into the
northern portions of Europe and North America …

var. _candicans_.

Lower tail-coverts always with markings. A tinge of ashy-blue more
or less prevalent above. Young dusky above.

Head and neck above abruptly lighter than the back. Young plain
grayish-brown above, with conspicuous whitish borders to the
feathers.

2. _Adult._ Upper parts white, passing into bluish
posteriorly; everywhere (except on head and neck) with sharply
defined, transverse (not crescentic, but continuous) bars of
dark plumbeous. Abdomen and flanks with transverse spots of
the same. _Young_ without irregular light mottling to the
plumage above, and with broad longitudinal stripes beneath.
_Hab._ Iceland and Southern Greenland, in the breeding-season;
in winter, south into Northeastern United States, and Northern
Europe …

var. _islandicus_.

Head and neck above abruptly darker than the back. Young (of
var. _sacer_) variegated grayish-brown above, without light
borders to the feathers.

3. _Adult._ Top of the head streaked with whitish; back with
sharply defined, continuous, narrow transverse bars, of
creamy-white. _Hab._ Interior regions of Continental Arctic
America (Slave Lake, Yukon, and McKenzie River district) …

var. _sacer_.

4. _Adult._ Top of head not streaked with whitish; back
without sharply defined bars of the same. _Hab._ Continental
Arctic Europe (Scandinavia) and Siberia. Migrating south, in
winter, to Bengal (Hardwicke) …

var. _gyrfalco_.[48]

_b._ Lower parts with dusky predominating, or wholly dusky.

5. _Adult._ Almost entirely dusky, without well-defined
markings anywhere. _Hab._ Littoral regions of the Hudson Bay
Territory and Labrador …

var. _labradora_.

=2.= =F. lanarius.= Wing, 11.50–16.00; tail, 6.60–9.50; culmen,
.70–1.00; tarsus, 1.90–2.40; middle toe, 1.65–2.00. Ground-color
varying from pale grayish-plumbeous to dark sepia-brown; beneath
white, with sparse markings, these coalesced into a broken patch on
the flanks. _Adult._ Above obscurely barred transversely with pale
ashy and brownish-dusky, the former prevailing posteriorly, the latter
anteriorly; a lighter nuchal band. Spots on the sides and flanks
transverse. _Young._ Above brown, varying from grayish-drab to dark
sepia, the feathers usually bordered with paler (rusty in youngest
individuals); markings beneath all longitudinal.

_a._ Outer webs of tail-feathers with large well-defined light
spots; outer webs of the primaries sometimes with light spots on the
basal portion; secondaries without distinct spots on the outer webs.
Lower tail-coverts immaculate.

Wing, 13.65–16.00; tail, 8.40–9.50; culmen, .85–1.00; tarsus,
1.95–2.15; middle toe, 1.85–1.95. Top of the head white, with
narrow streaks of dark brown. _Hab._ Central and Eastern Europe,
Western Asia, and adjoining portions of Africa …

var. _lanarius_.[49]

_b._ Outer webs of tail-feathers without distinct light spots, or
without any at all; outer webs of primaries with no trace of spots;
secondaries with light spots on outer webs. Lower tail-coverts
sparsely spotted.

Wing, 12.00–14.25; tail, 7.60–9.00; culmen, .75–.90; tarsus,
2.15–2.40; middle toe, 1.70–2.00. Top of head brown, with narrow
black streaks. _Adult._ Above with obscure transverse spots of
bluish. _Young._ Above with feathers bordered with rusty …

var. _polyagrus_.

Wing, 11.50; tail, 6.60; culmen, .70; tarsus, 1.90; middle toe,
1.65. Above uniform dark brown, with a faint plumbeous cast, the
feathers without trace of light or rusty edges; outer web of
tail-feathers without trace of light spots. _Hab._ Mexico …

var. _mexicanus_.[50]

Wing, 13.60–14.30; tail, 8.25–9.00; culmen, .80–.87; tarsus,
1.85–1.90; middle toe, 1.85–1.90. Colors similar to the last;
entire auriculars white; mustache narrow and conspicuous. _Hab._
Southern Asia …

var. _jugger_.[51]

The only point of difference in the external anatomy between the Lanner Falcons and Gerfalcons consists in the different degree of feathering on the upper part of the tarsus; this is much denser and extends farther down and more around the posterior face in the Gerfalcons, but they, being inhabitants of a very northern latitude, need this protection against the rigor of the climate. These slight specific differences are illustrated by the figures on page 1430. The same difference is observable in many birds whose habitat extends through a great range of latitude, as, for instance, the _Pediocætes phasianellus_, the northern race of which has the feathers covering the base of the toes so long as to reach beyond the claws and nearly conceal them, while in the southern form (var. _columbianus_) the toes are almost completely naked.

My determination of the number and character of the geographical races of _F. gyrfalco_ is the result of a very careful critical examination of over sixty specimens, aided by the important conclusions of Mr. Hancock (Annals and Magazine of Natural History, 2d ser., XIII, 110; London, 1834), Schlegel (_Falcones_, Muséum d’Histoire Naturelle des Pays-Bas, 1862), Pelzeln (Uebersicht der Geier und Falken der Kaiserlichen ornithologischen Sammlung, April, 1863), and Alfred Newton (History of British Birds, revised ed., part 1, June, 1871, pp. 36–52, and Proc. Acad. Nat. Sc. Philadelphia, July, 1871, pp. 94, 95), in their important papers bearing upon this subject, which, though they each express the peculiar individual views of the writer, together clear up pretty satisfactorily the problem of the number, character, and habitats of the several races, as well as the different phases of variation to which each is subject.

_Falco sacer._]

_Falco polyagrus._]

In studying the _F. lanarius_, I have experienced most discouraging difficulties from the want of sufficient series of the Old World races, and from the unsatisfactory character of most descriptions and figures of them, besides being much perplexed by the confusion of their synonymy by different authors. In consequence of this, my diagnoses of the four races of which alone I have seen examples may be very unsatisfactory as regards the characters by which they may be most readily distinguished. Having seen the adult of only a single one of these four races, I am therefore compelled to base my differential characters upon the immature stages.

In addition to the four races of _F. lanarius_ characterized above, there are several geographical forms belonging to the Old World, chiefly intertropical Asia and Africa. These are the var. _babylonicus_, Scl. and Irby, (Gray’s Hand List, I, p. 20, No. 173,) of Southeastern Europe and Western Asia; var. _barbarus_, L. (Gray’s Hand List, p. 20, No. 174), of Northern Africa; and var. _tanypterus_, Licht. (Gray’s Hand List, No. 175), of both the preceding regions, which Mr. Gurney writes me “is simply the intertropical race of _F. lanarius_, from which it only differs in being of a darker shade throughout.” The _F. saker_, Schleg. (Gray’s Hand List, No. 176), seems, to judge from the descriptions and figures which I have seen, to be also merely a form of the same species, but I have seen no specimens of it.

Falco (Hierofalco) gyrfalco, LINN.

Var. =candicans=, GMELIN.

WHITE GERFALCON.

_Accipiter falco freti hudsonis_, BRIS. Orn. I, 356, 1763. _A.
gyrfalco_, BRISS. Orn. I, 370, pl. xxx, f. 2, 1763. _Falco
rusticolus_, FABR. Faun. Grœn. p. 55, 1780.—LATH. Syn. Supp. I, 15,
1781. _F. candicans_, GMEL. Syst. Nat. p. 275, 1788.—DAUD. Tr. Orn.
II, 101, 1800.—BENICK, Isis, 1824, 882.—SCHLEG. Krit. Ubers. p. 1,
1844.—BONAP. Rev. Zool. 1850, 484; Consp. Av. p. 33.—CASSIN, Proc.
Ac. Nat. Sc. Phil. 1855, 278; Birds N. Am. 1858, 13.—STRICKL. Orn.
Syn. I, 77, 1855.—BLASIUS, Cab. Jour. 1862, 43 (thinks all boreal
ones same in Europe and America).—ELLIOT, Birds N. Am. pl. xii.
_Hierofalco candicans_, CUV. Reg. An. ed. 1, I, 312, 1817; ed. 2, I,
323, 1829.—LESS. Man. Orn. I, 80, 1828; Tr. Orn. p. 97, pl. xvi, p.
2.—GRAY, Hand List I, 18, 1869. _Falco islandicus_, LATH. Ind. Orn. p.
32, 1790; Syn. I, 71, A, B; Gen. Hist. I, 72, A, 1821.—STEPH. Zool.
XIII, pt. ii, p. 39, 1826.—GOULD, B. Eur. pl. xix.—AUD. Birds Am.
1831, pl. ccclxvi. _F. buteo_ β, LATH. Ind. Orn. p. 24, 1790; Gen.
Hist. I, 80, A. _F. lagopus_, β, LATH. Ind. Orn. p. 19, 1790; Syn.
Supp. I, 36; Gen. Hist. I, 68, A. _F. grœnlandicus_, DAUD. Tr. Orn.
II, 157, 1800. _Hierofalco grœnlandicus_, BREHM. Voy. Deutsch, I, 16,
1831. _F. gyrfalco_, BONAP. List, p. 4, 1838.

SP. CHAR. _Adult_ (♀, 18,577, Greenland; Univ. Zool. Mus. Copenhagen). Ground-color entirely pure white; whole upper surface (posterior to the nape) with transverse crescentic bars of dark plumbeous-brown, generally about two on each feather, the first concealed by the feather which overlaps. Primaries crossed at regular intervals with quadrate spots of the same tint, these becoming fused toward ends of quills, forming a terminal dusky space of two or three inches in extent; tips of all the quills narrowly white; the black bars do not extend quite to the primary coverts, and decrease both in extent and regularity toward the base. Middle tail-feathers crossed with seven or eight imperfect bars of dusky, the shafts of the feathers blackish; rest of tail immaculate, the shafts pure white. Nape with a very few fine shaft-streaks of dusky. Whole lower surface of body and wing utterly immaculate. Wing-formula, 2–3–1. Wing, 16.50; tail, 9.00; culmen, 1.05; tarsus, 2.10–1.35; middle toe, 2.20; inner, 1.50; outer, 1.50; posterior, 1.00.

(No. 56,152, ♀, Greenland; Schlüter Collection.) Head above, occiput, nape, and upper half of ear-coverts, with sparse shaft-streaks of black, these most numerous on the latter region; primaries barred to the coverts. Tail entirely crossed by eleven plumbeous bars. Bars above clearer plumbeous. The snowy-white beneath is relieved by a few minute variable flecks of dusky upon the lower part of the abdomen, becoming larger as they approach the sides. Wing-formula, 2–3–1. Wing, 16.70; tail, 9.30.

_Juv. transition stage?_ (♂ 56,047, “Hoher Norden”; Schlüter Collection). Markings above quite different from those of the two preceding; each feather has a large central longitudinal sagittate spot of dusky, leaving only the borders (of the exposed portion) white; on the primaries the dusky is almost confined to the terminal portion; the rump and upper tail-coverts have each feathers with a medial longitudinal stripe of dusky. The tail is immaculate, but the shafts of the middle feathers are dusky. The neck, breast, abdomen, and sides have numerous cuneate marks of dusky, one near the end of each feather. The lining of the wing, even, has a few narrow streaks. Wing, 14.75; tail, 9.40.

No. 56,049 (♀, Greenland, Schl. Coll.) is similar in pattern of markings, but above the dusky is more extended, forming the predominating color; the rump, etc., has broad sagittate spots instead of narrow stripes; the primaries are barred to the coverts; the tail is crossed by about ten continuous bands of dusky. Beneath the lanceolate spots or streaks cover the whole surface, except the anal region, lower tail-coverts, and throat. On the lining of the wing the streaks are less sparse than in the preceding, though they are by no means numerous. Wing, 15.75; tail, 9.50.

_Juv. first plumage_ (♀, 56,053, Greenland; Schlüter Coll.). All the markings are longitudinal, instead of directly the reverse. The upper parts have longitudinal tear-shaped stripes, a medial one on each feather; they are sparse, however, on the wings; the rump has narrow shaft-lines of dusky. The tail and upper coverts are immaculate, but the shafts of all the feathers are nearly pure black. The bars on the primaries are found only immediately next the dusky terminal space. The streaks beneath are not very numerous, and are found only on the breast, upper part of abdomen, and on the sides; the nape and sides of the neck are, however, thickly streaked.

(No. 17,966, ♀, Moose Factory, Hudson Bay Territory.) In character of markings resembling the last, but the stripes are fainter and narrower; they are also less numerous. On the under parts they are wanting. Unfortunately, the tail of this specimen, which is the only North American one in the collection, is missing.

In all specimens the anal region and lower tail-coverts are immaculate.

HAB. Greenland, and continent of North America, north of Hudson Bay (breeding in latter region). Of irregular occurrence in winter throughout the circumpolar regions; Ural Mountains (EVERSMAN); Behring’s Strait (BANNISTER).

LIST OF SPECIMENS EXAMINED.

National Museum, 7; Boston Society, 2; Philadelphia Academy, 3; New York Museum, 6; collection of R. Ridgway, 1. Total, 19.

_Measurements._

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |14.40–14.75| 9.70–00.00| .90–0.00|2.15–2.45| 1.95–2.00| 3 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |15.75–16.25|10.00–11.00| .98–1.00|2.20–2.50| 2.05–2.15| 6 | +----+-----------+-----------+---------+---------+-----------+----------+

Var. islandicus, SABINE.

ICELAND GERFALCON.

_Accipiter falco islandicus_, BRISS. Orn. I, 336, 1763. _Falco
islandicus_, SAB. Linn. Trans. XII, 528, 1818.—TEMM. Man. Orn. pt.
x; 17, pt. iii, p. 9; Tab. Meth. p. 2, 1836.—FABER, Prod. Island.
Orn. 1822, p. 2; Isis, 1827, 62.—RICH. & SWAINS. F. B. A. II, 27,
1831.—HOY, Mag. Nat. Hist. Ser. 1, VI, 107.—HANCOCK, Ann. Nat. Hist.
II, 247; Rev. Zoöl. 1839, 123.—BONAP. Consp. Av. p. 24.—STRICKL.
Orn. Syn. I, 77, 1855.—CASSIN, Birds N. Am. 1858, 13. _Hierofalco
islandicus_, GRAY, Gen. B. p. 3 (ed. 2, p. 4), 1844; Hand List, I, 18,
1869. _Falco candicans islandicus_, SCHLEG. Krit. übers, p. 1, 1844.
_Falco lanarius_, FABER, Isis, 1827, 68. _Falco gyrfalco_, KEYSERLING
& BLASIUS, Wirbelth. Eur. p. 135, 1840.

SP. CHAR. _Adult_ (♂, Iceland; No. 12, Coll. Geo. N. Lawrence). Ground-color of the plumage dull white, gradually becoming somewhat bluish posteriorly, this color especially noticeable on the tail. Whole upper parts crossed with broad transverse bands of dark plumbeous, these bands continuous, and more than twice as wide as the pale ones, except on the upper tail-coverts and tail, where the bands of the two colors are more regularly defined and about equal; in addition to the transverse bands, the feathers anteriorly have narrow borders of white. Tail with the dark bands twelve in number; the terminal pale band is purer white than the others. The dusky plumbeous prevails on the primaries, and is unvariegated beyond the middle portion; the anterior half, however, is marked with quadrate ragged spots, of a slightly yellowish-white; all are margined terminally with purer white. Each feather of the head and neck with a narrow medial streak of dusky, but the general aspect abruptly lighter than the back; the streaks are more condensed along the upper and terminal portion of the ear-coverts. Jugulum and breast with a medial narrow streak on each feather; abdomen with more elliptical streaks; sides with circular and cordate spots, and flanks and tibiæ with transverse spots; lower tail-coverts with narrow shaft-streaks of dusky. Lining of the wing with sparse narrow streaks of dusky; under surface of primaries with white prevailing, this, however, crossed by narrow bars of dusky, these numbering about sixteen on the longest. Wing-formula, 2–3–1. Wing, 14.60; tail, 7.80; culmen, 1.00; tarsus, 2.30; middle toe, 2.00.

_Juv._ (No. 20,344, Iceland). Ground-color of head, neck, and lower parts, white. Upper surface grayish umber-brown, becoming paler and more grayish on the tail; each feather above sharply bordered (both webs, all round) with dull white, producing a somewhat squamate appearance; in places, a few obsolete hidden spots of yellowish-white. Tail ashy-drab (feathers somewhat paler along edges), crossed with about eleven transverse series of spots of ochraceous or creamy white; these very obsolete on middle feathers, and sharply defined only on inner webs; the last is terminal. Primaries plain brown, somewhat darker than the back, and becoming insensibly darker terminally; skirted with white, and somewhat mottled or irregularly spotted toward their bases with yellowish-white. Head and neck, each feather, with a medial streak of dusky, but white the prevailing aspect; these streaks condensed and somewhat suffused along upper border of ear-coverts, and from the lores along cheeks, forming an obsolete “mustache”; every feather beneath (including lining of wings) with a medial broad stripe of clear plumbeous vandyke-brown, the shaft pure black; under surface of primaries with transverse spaces of white, these numbering thirteen on the longest. Wing-formula, 2–3, 1. Wing, 15.00; tail, 9.20.

HAB. Iceland and Southern Greenland. Northeastern North America in winter, straggling accidentally south to the New England States; Rhode Island (Museum, Cambridge); Norway, Maine “not uncommon” (VERRILL); Massachusetts (PEABODY & JILLSON); Long Island (CAB., G. N. LAWRENCE).

No. 56,050, Greenland (Schlüter Collection), is moulting, and assuming the adult dress; the adult and young stages above described being nearly equally combined. No. 56,055, from Greenland, differs from the other young individuals which I have seen in being considerably darker. The feathers of the upper surface are not bordered with whitish, but are merely paler on their edges, along which are specks of yellowish. On the head and neck the dark streaks predominate, while the stripes below are very broad. It approaches quite nearly toward the young of var. _sacer_.

The only specimen of this race which I have seen from Continental North America, is a young individual, obtained during the winter of 1864–65, near Providence, R. I., taken by Mr. Newton Dexter, and now in the Cambridge Museum, where I had the pleasure of seeing it.

LIST OF SPECIMENS EXAMINED.

National Museum, 5; Boston Society, 3; Philadelphia Academy, 9; Coll. G. N. Lawrence, 2; Museum Comp. Zoöl., 1; New York Museum, 5. Total, 25.

_Measurements._

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |14.35–14.75| 8.80–10.00| .91–1.00|2.20–3.00| 1.95–2.15| 9 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |16.25–16.50|10.00–11.50|1.00–1.05|2.30–2.70| 2.00–2.25| 10 | +----+-----------+-----------+---------+---------+-----------+----------+

Var. sacer, FORSTER.

MacFARLANE’S GERFALCON.

_Falco sacer_, FORSTER, Phil. Trans. LXII, 1772, 383 and 423.—COUES,
Birds of New England, 1868, 6.—BAIRD, Trans. Chicago Acad. Sc. I, ii,
271. _? Falco cinereus_, GMEL. Syst. Nat. p. 267, 1789.

SP. CHAR. _Adult_ (♂, 51,689, Yukon, mouth of Porcupine River; Strachan Jones). Whole upper surface with numerous transverse bands of brownish-plumbeous and ashy-white. Anteriorly the light bars are about half the width of the dark ones; posteriorly they gradually increase, the bands of the two colors being about of equal width on the upper tail-coverts and tail; with the increase of the lighter bars, they become more ashy, and, correspondingly, the darker ones are more plumbeous; on the rump there is but little contrast between the bands of the two, causing a prevalent bluish cast. The bands are everywhere continuous, the light ones being interrupted only by the black shaft; there are generally on the anterior portions about three light bars on each feather, the last always terminal. Tail tipped with white, and crossed with equal continuous bands of hoary-plumbeous and ashy-white; the latter eleven in number, and finely sprinkled with deeper ash. Primaries brownish-plumbeous, plain past the middle portion, but on the anterior half with quadrate spots of creamy white on the outer web. Head above brownish-plumbeous, this prevailing; but along the median line the feathers are edged with buffy white; forehead dull white, this continuing back in a streaked superciliary stripe to the occiput; cheeks very thinly marked with fine streaks of dusky, this prevailing along the upper border of the ear-coverts; a deeper dusky suffusion beneath the anterior angle of the eye. Lower surface pure white; chin and throat, only, immaculate; jugulum with very sparse, narrow longitudinal streaks of blackish; sides with scattered cordate or nearly circular spots, these larger and transverse on the flanks and tibiæ; abdomen with scattered minute elliptical spots; lower tail-coverts with minute irregular sagittate or transverse spots of dusky. Under surface of the wing white; each feather of the lining with a medial tear-shaped streak of dusky; primaries crossed with narrow bars of dusky, fifteen in number on the longest. Wing-formula, 2–3–4–1–5. Wing, 13.50; tail, 8.60; culmen, .90; tarsus, 2.15; middle toe, 1.87.

♀ (43,139, Fort Anderson, May 24, 1864, “♀ and two eggs”; R. MacFarlane). Generally similar to the male. Head above conspicuously streaked, but the dusky prevailing. Above the transverse bands are less regular and continuous, anteriorly the plumbeous largely prevailing; posterior portions, however, as in the male, but on the rump the bands are more distinct. Beneath, the markings are more numerous, larger, and broader; those on the jugulum linear; those of the abdomen medially elliptical; laterally they are transversely cordate, and on the flanks in form of broad transverse spots, or broad bars; on the tibiæ and lower tail-coverts they form regular transverse bars,—on the latter, quite distant. Wing-formula, 2–3–4, 1. Wing, 15.50; tail, 9.50; tarsus, 2.15 and .80; middle toe, 1.95.

_Juv._ (♂, 55,400, Alaska, Nulato, February 10, 1868; W. H. Dall). Above plumbeous-umber, precisely as in young of _islandicus_, but on the rump having a decided ashy cast. No white edges to the feathers, as in _islandicus_, but, instead, numerous irregular transverse spots or obsolete ragged bars of cream-color or pale ochraceous-buff; the whole upper surface is quite thickly variegated with these irregular markings. Tail crossed with thirteen narrow bands of creamy-white, these so thickly mottled with dusky on the outer webs as to be obscure, but on inner webs they are regular and sharply defined; the last is terminal. Primaries plain dusky, skirted obscurely with paler, and marked toward bases with obsolete mottled spots of cream-color. Head streaked with dusky and creamy-white, the former predominating on upper surface, along upper edge of ear-coverts, and across the cheeks, on the latter forming a mustache; the white prevails over the ear-coverts in a broad supra-oral stripe, and on the forehead and lores. Beneath, soft dull white; chin and upper part of throat, only, immaculate; each feather with a broad medial stripe of clear dark plumbeous-brown, on the flanks and tibiæ prevailing, the whitish assuming the form of roundish spots; lining of the wing similarly marked; prevailing aspect of under surface of primaries white, crossed with narrow bars of ashy, fifteen in number on the longest. Wing-formula, 2, 3–1=4. Wing, 14.00; tail, 8.40.

HAB. Interior regions of Arctic America; Anderson River, McKenzie, Yukon, and Severn River regions. Breeding abundantly in the former district, whence numerous specimens of skins and eggs have been received by the Smithsonian Institution.

In the young specimen described, there are one or two new feathers appearing on the rump and upper tail-coverts, precisely as in the blue plumage, and proving conclusively their relationship. The species is as different from the Iceland bird in the young stage as in the mature. The most readily apparent differences are, lack of sharp white edges of feathers above, and in their stead numerous ragged transverse spots of yellowish; dark aspect of head above, etc.

Specimens vary considerably in the shades of color and distribution of the markings, but the types of the above descriptions are the lightest of the series. The darkest example is No. 43,144½ (“♀ and eggs”), Fort Anderson, May 22, 1864. In this the whole head and neck (except underneath) are continuous blackish-plumbeous, only the middle of the auriculars being faintly streaked; the back is nearly plain dusky, and even on the wings the bars are very obscure and much reduced in width. The rump is plain ashy-blue, the darker bars being nearly obsolete. The longitudinal markings on the pectoral region are enlarged into conspicuous stripes, while on the sides and flanks the transverse bars form heavy spots. The transverse bars on the tibiæ are ashy-blue; those on the crissum clear plumbeous, and regularly transverse. Wing, 15.75; tail, 9.30. Upon comparing this specimen with the figures of a pair of var. _gyrfalco_, by Wolf, in Newton’s Oötheca Wolleyana, I can discover no difference at all; thus it would seem that our bird occasionally closely approaches in tints and markings this race of Continental Europe, of which I have seen only one immature example, and no adults.

I cannot agree with Mr. Newton in considering the Gerfalcons of the interior of Arctic America as identical with the Iceland form, though that distinguished ornithologist considers them so in his paper in the Proceedings of the Philadelphia Academy for July, 1871, basing his conclusion upon the specimens from which the above descriptions were taken, which had been sent over to England for comparison. I have never yet seen a specimen of _islandicus_ which could not be distinguished, by the characters given in my synopsis, from these examples, while they can be separated from that race by the characters which Mr. Newton himself gives, in his diagnostic table in the paper above cited, for distinguishing the adults of _islandicus_ and _gyrfalco_.

The var. _sacer_ is evidently separable from both _islandicus_ and _gyrfalco_, and about as much related to one as to the other; combining the size and proportions of the former with the colors of the latter, while in the wide amount of individual variation of plumage its lighter extreme approaches one, while its darkest phase approximates as closely to the average plumage of the other.

LIST OF SPECIMENS EXAMINED.

National Museum, 6.

_Measurements._

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |13.35–14.25| 8.50–9.00| .86–.93|2.15–2.40| 1.80–1.95| 3 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |15.50–16.00|10.00–10.50| 1.00–.00|2.35–2.55| 2.00–2.15| 3 | +----+-----------+-----------+---------+---------+-----------+----------+

Var. labradora, AUDUBON.

BLACK GERFALCON.

_Falco labradora_, AUD. B. Am. pl. cxcvi, 1831.

SP. CHAR. _Adult_ (♀ breeding plumage? 30,375, Rigolet, Labrador; Mr. Conolly). Ground-color of the plumage uniform, very deep, clear, dark plumbeous-brown, continuously uniform above; larger scapulars, secondaries, secondary coverts, and primaries more dilute along edges, however, the tint palest and broadest terminally. Tail perfectly uniform, except at the end; the tip being narrowly whitish, and about half an inch anterior to this, a transverse series of hidden irregular transverse creamy-white spots. The head (except beneath) is unvariegated. Beneath, the dark tint inclines more to blackish clove-brown, more dilute on the tibiæ; feathers edged laterally with white, this prevailing on the throat, but everywhere else far less than the dusky in amount; on the tibiæ and lower tail-coverts the white is in the form of irregular spots. Anal region unvariegated; lining of the wing with circular spots of white along the outer webs of the feathers. Under surface of primaries with plumbeous prevalent, but this crossed with mottlings of whitish, forming transverse bars; but terminally and basally they become confused or lost. Wing-formula, 2, 3–1, 4. Wing, 16.20; tail, 9.50; tarsus, 2.00–.90; middle toe, 2.05; inner, 1.50; outer, 1.50; posterior, .90.

HAB. Labrador; south and westward in winter, and shores of Hudson Bay.

Nos. 17,063 (♀, Quebec, W. Cooper) and 34,960 (♀, Fort Nescopec, Labrador) differ from the preceding in having ten small narrow transverse spots of reddish-white on the tail-feathers, forming as many indistinct bands; these spots touch neither the shaft nor the edge of the feather, and are almost concealed, unless the tail is spread; on the latter specimen they are very obsolete, the subterminal one only being distinct, as in the specimen selected for description. The upper tail-coverts also show faintly indicated spots, and the former specimen has the wing-coverts with very narrow irregular spots on the edge of the feathers. In this specimen there is also one feather in the scapulars which has broader white edges; it also has the white below about equal to the black in amount; the anal region, however, in all, is unvaried blackish, and the transverse oblique bands on the lower tail-coverts are a constant feature.

No. 41,185 (♀, Fort Nescopec, Labrador; H. Conolly) is the darkest of all. In this the blackish plumbeous-brown is uniform over the whole surface; even the throat is unvariegated. Abdomen with a few of the feathers edged with white, and sides with a few small circular spots of the same; lower tail-coverts transversely spotted with white; tibiæ scarcely variegated, showing only narrow indistinct whitish edges. Mottling on inner webs of primaries reduced so as to be scarcely visible. Tail with the usual number (two) of irregular whitish bars,—one terminal, the other near the end.

LIST OF SPECIMENS EXAMINED.

National Museum, 2; Boston Society, 1. Total, 3.

_Measurements._

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |14.50–00.00| 9.00–00.00| .90–0.00|2.12–0.00| 1.90–0.00| 1 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |15.50–15.75| 9.50–10.00|1.00–1.05|2.00–2.35| 2.00–2.10| 2 | +----+-----------+-----------+---------+---------+-----------+----------+

HABITS. In treating of the general habits of the Gerfalcons of North America it will not be necessary, nor will it be possible, to give the distinctive peculiarities belonging to the several forms in which these Falcons occur. Whether, on account of their variations of plumage, we consider them as races or as specifically distinct, does not affect their history in this respect. There is no good reason for presuming that they have any very noticeable variations as to any of their habits, although certain writers claim for some of them certain well-marked peculiarities of character.

In the matter of geographical distribution they are all, for the most part, rarely seen, even in midwinter, south of the 50th parallel of north latitude, and are found in the summer as far north as the Arctic Ocean. The Gerfalcon of the McKenzie River region, occurring from the Slave Lake to Anderson River and the Yukon, is the form elsewhere given as the _F. sacer_. Along our eastern coast region occurs another form, the _F. labradora_, which is the bird met with in Labrador, and described by Mr. Audubon. The _F. candicans_ or _grœnlandicus_ is a form peculiar to Greenland, visiting also, in the winter, the Hudson’s Bay region; while the _F. islandicus_, a well-known European form, occurs in Greenland also, and occasionally farther south.

Holböll, in his account of the birds of Greenland (Isis, 1845), appears to recognize but one species of Gerfalcon as occurring there, to which he gives the name of _islandicus_. This is, he states, the most abundant Falcon in Greenland, and is equally common in the northern and in the southern parts. Their great variations in color he regarded as indicative of differences in ages to only a very limited extent, and as in no respect specific. These differences in color were found among both nestlings and breeding birds, white and dark birds being found together in both circumstances. The white birds were more numerous in Northern Greenland, and the dark ones oftener seen in the southern portion.

He found the young birds moulting throughout the winter. On the 4th of January, 1840, he shot a young female that showed signs of moulting about the head and neck, with a striped white appearance from the sprouting feathers. The ovaries were quite well developed, and it was evident that the birds of this species breed in the first season after their birth. Holböll adds that they breed in January, that their eggs are of nearly the same color as those of the Ptarmigan, but are twice as large. They nest usually in inaccessible cliffs. They prey chiefly upon water-fowl and Ptarmigans, and usually build near “bird rocks,” from which they obtain the young without much trouble. He mentions having once seen one with a young _Larus tridactylus_ in each foot, and another with two _Tringa maritima_ carried in the same manner. Its rapidity of flight Holböll did not regard as very great. He had for years kept pigeons, and only lost two young birds, which were seized when at rest. Almost every day, especially in October and November, these Falcons would chase the old Pigeons unsuccessfully, and were often shot when they followed them too near the house. They were not particularly shy, and were occasionally decoyed and killed by throwing a dead bird towards them.

During the summer they are most numerous along the bays, especially where there are “bird-rocks” near. In September they go southerly along the coast, and also in October and November. At this time they are not rare, and approach the houses of the Danes, near which they are often seen fighting with the Ravens. Their spring migrations are not so regular as they are in the autumn, or perhaps at this time they do not approach the houses so frequently. When they are near the settlements, it is noticed that in the morning they fly towards the south, and in the evening towards the north.

Richardson speaks of the Gerfalcon as a constant resident in the Hudson Bay territory, where it is known as the Speckled Partridge-Hawk, and also as the Winterer. Its southern limit he could not give, but he never met with it south of 52°. He traced it northward to the coast of the Arctic Sea, and probably to the most northern Georgian islands. He cites Captain Sabine as authority for its occurring as far north as latitude 74° on the west coast of Greenland. Richardson often met with it during his journeys over the Barren Grounds, where its habitual prey was the Ptarmigan, and where it also destroyed Plover, Ducks, and Geese. He relates that in the middle of June, 1821, a pair of these birds attacked him as he was climbing to the vicinity of their nest, which was built on a lofty precipice on the borders of Point Lake, in latitude 65° 30′. The bird flew in circles, uttering loud and harsh screams, stooping alternately with such velocity that their motions through the air produced a loud rushing noise. They struck their claws within an inch or two of his head. Keeping the barrel of his gun close to his cheek, and suddenly elevating its muzzle when they were in the act of striking, he found that they invariably rose above the obstacle with the rapidity of thought, showing equal power of motion. They bore considerable resemblance to the Snowy Owl, but their flight was much more rapid.

Mr. MacFarlane, in the memoranda of his collections in the neighborhood of Anderson River and Fort Anderson, furnishes notes of eighteen nests of the Gerfalcon obtained by him in that region. With only two exceptions, these were placed near the tops of pines, or other trees, at distances from the ground varying from ten to twenty-five feet. In some instances the nest was placed on the very top of the tree, in others on a lower limb against the trunk. They were composed of twigs and small branches, and lined with mosses, hay, deer’s hair, feathers, and other substances. The parents were always very much excited whenever their nests were approached, making a great noise, and not unfrequently their loud screams drew attention to nests that would otherwise have escaped notice. In one instance a nest had been built on a ledge of rocks thirty miles northwest of Fort Anderson. It was composed of a few withered twigs, and lined with mosses and hay. It was found on the 27th of May, and contained two eggs nearly fresh, and two in a state of greater development. One nest, placed on a broad branch of a tree, near the trunk, was of considerable size. Another nest was on the ground, on the side of a steep and high hill. The earliest date of finding these nests is given as the 10th of May. The eggs then found were fresh. The ground at that time was still thickly covered with snow, and the weather was very cold. In a nest found five days later the eggs contained partially developed embryos. In nearly every instance the eggs seem to have been in different stages of development in the same nest. In some, young birds were in the same nest with eggs only partially developed, and in another an egg perfectly fresh was in the same nest with others nearly ready to hatch. A nest found July 3 contained young about two days old; another, on May 27, had eggs with large embryos; and one, on June 25, had young nearly ready to fly.

Mr. Donald Gunn claims that this Falcon is the only Hawk that is resident in the Arctic regions throughout the year. It is known to the Indians by the name of Pepunesu, and this name is applied to it because it passes the winter with them. It is a very powerful bird, and commits great havoc among the Partridges, so much so that in former times the Hudson Bay Company gave a reward of a quart of rum to every hunter who brought in the head of one of these Falcons. All the other Hawks are only summer visitors.

Mr. Bannister was informed by the residents of St. Michaels that a Hawk, presumed to be this species, is not unfrequent there, though he did not happen to meet with it. On his voyage home, on the 21st of October, 1866, when off the coast of Kamtschatka, north of Behring’s Island, one alighted in the rigging of the ship, and continued with them for several hours.

Although very rare in any part of the United States, occasional individuals have been taken in different localities, and in one instance a pair was known to breed for several successive seasons in Vermont. This information I have from Mr. Clarence King, who, when a lad at school in the town of Dummerston, observed a pair nesting among some high cliffs, and informed me of the fact at the time of the occurrence. One of these birds is recorded by Mr. Lawrence as having been taken on Long Island in the winter of 1856.

Mr. Boardman gives it as occurring near Calais in winter, but very rare. Professor Verrill found them not uncommon in Oxford County, Me., where they were frequently seen during winter, flying about the extensive meadows near Norway; but they were very shy and watchful, and it was hardly possible to procure a specimen. It is very unusual in Eastern Massachusetts, and only very rarely and occasionally have specimens been taken. Mr. Jillson obtained a specimen, in 1840, at Seekonk. One was shot, in 1864, near Providence, R. I., by Mr. Newton Dexter.

Mr. Audubon relates that, August 6, 1833, his son, John W. Audubon, found a nest of this Falcon among some rocky cliffs near Bras d’Or, Labrador, containing four young birds ready to fly, two of which were procured. The nest was placed among the rocks, about fifty feet from their summit and more than a hundred from their base. It was inaccessible, but, having been examined from above, was seen to be empty. It was composed of sticks, sea-weeds, and mosses, was about two feet in diameter, and was almost flat. Its edges were strewed with the remains of their food, and beneath the nest was an accumulation of the wings of Ptarmigans, Mormons, Uriæ, etc., mingled with large pellets of fur, bones, and various substances.

Their flight is spoken of as similar to that of the Peregrine Falcon, but more elevated, majestic, and rapid. Their cries were also like those of that Falcon, being very loud, shrill, and piercing. Occasionally this bird was seen to alight on one of the high stakes placed on the shore. There it would stand, in the position of a Tern, for a few moments, and then would pounce upon a Puffin, as the latter bird was standing at the entrance of its burrow, unaware of the approach of its enemy. The weight of the Puffin seemed to form no impediment to the Hawk in its flight.

The European Gerfalcons are said to seldom appear south of the 52d parallel of latitude, or north of 74°. They are nowhere numerous, and were formerly much sought for, and purchased, at immense prices, for purposes of falconry. Great differences were supposed to exist in regard to the habits and other peculiarities of the several races. The Iceland Falcons commanded the highest prices, and were regarded as a species quite distinct from the _F. gyrfalco_. The former was much the more valuable, both as more rare, and as a bird of higher courage and of a more rapid and bolder flight, and a bird that could, on that account, be “flown” successfully at larger game.

The Gerfalcons, in Europe, build on the rocky coasts of Norway and Iceland, and are said to defend their young with great courage and determination. They are comparatively rare in the British Islands, especially the more southern portions. Even in the Orkneys it is only an occasional visitor.

All the eggs of the several forms of Gerfalcon that I have seen present common characteristics, and do not differ from each other more than eggs known to belong to the same species of Hawk are frequently found to vary. One from Greenland, presumed to belong to the _candicans_, measures 2.37 inches in length by 1.71 in breadth. The predominant color of its markings is a deep reddish-brown, very generally and nearly equally diffused over its surface, concealing the ground-color, which is lighter and of a yellowish-brown shade.

An egg of the _islandicus_, from Iceland, has the same measurements, but is so slightly yet uniformly marked with light yellowish-brown as to seem to be of one color only,—a light brown, shaded with yellow.

An egg from Norway, of the form _gyrfalco_, is 2.42 inches in length, 1.71 in breadth, has a ground-color of a dirty yellowish-white, and is marked with spots, dottings, and confluent blotches of yellowish-brown, more so about the larger end.

The series of eggs of _Falco sacer_ in the Smithsonian Collection exhibits the following range of variation in size, color, and markings: length, from 2.30 to 2.45 inches; breadth, 1.60 to 1.90 inches; ground-color usually a light reddish-ochre, varying to pinkish on the one hand, and to rufous on the other. They are usually sprinkled all over with small spots, which are sometimes not distinguishable from the ground-color when this is very deep, and again larger and quite conspicuous.

An egg of the variety _candicans_, from Greenland (No. 2,606, S. I.), measures 2.25 inches by 1.80. In color and in markings it is like the average eggs of variety _sacer_, namely, pale rufous, sprinkled over with a slightly deeper shade.

Falco lanarius.

Var. =polyagrus=, CASSIN.

AMERICAN LANNER; PRAIRIE FALCON.

_Falco polyagrus_, CASSIN, B. Cal. & Tex. 1853, 88.—IB. P. A. N. S.
1855, 277; B. N. Am. 1858, 12.—HEERM. Pacific R. Rep’t, II, 1855,
31.—KENNERLY, P. R. R. III, 1856, 19.—COOP. & SUCKL. P. R. R. XII,
1860, 143.—COUES, P. A. N. S. 1866, 7.—STRICKL. Orn. Syn. I, 1855,
85.—DRESSER, Ibis, 1865, 323.—GRAY, Hand List, I, 1869, 20. _Falco
lanarius_, var. _mexicanus_, RIDGWAY in COUES’ Key, 1872.

SP. CHAR. _Adult_ (♂, No. 59,063, Wahsatch Mountains, Utah, May 23, 1868; parent of eggs; L. E. Ricksecker). Above cinereous-drab, becoming gradually paler and more bluish posteriorly, barred, indistinctly, everywhere with a more dusky tint, the shafts of all the feathers blackish; anteriorly the darker shade predominates, while posteriorly the bluish prevails; on the anterior portions the light bars are much restricted in width, and of a more ochraceous tint. Tail plain, very pale ashy-drab, narrowly tipped with reddish-white, this changing to pale rusty on the middle pair; the concealed portion of the feathers outside the shaft show obsolete, or faint traces of, darker bars, which on the middle pair are apparently about eleven in number. On the inner webs the paler bars become broader than the darker ones, and incline to ochraceous in tint, the lateral feather being edged externally with this color. Primaries plain ashy-drab, with a hoary tinge, growing insensibly darker terminally, and with a slightly paler apical margin. Head and neck above, dark umber-brown, with conspicuous shaft-streaks of black. Lores, a broad superciliary stripe (somewhat interrupted above the eyes), white, finely and sparsely streaked, the two stripes confluent across the occiput; a broad heavy “mustache” from the lores and rictus downward and obliquely backwards, across the maxilla, and a wider postocular stripe, like the crown. Beneath continuous white, with a faint ochraceous tinge on the abdomen and crissum; abdomen and sides of the breast with a few scattered, small, ovate spots of vandyke-brown; sides transversely spotted with vandyke-brown, the spots coalesced into a broken patch on the flanks; outside of the tibiæ with transverse spots of the same. Axillars plain, clear vandyke-brown, with a few nearly obsolete rusty specks near their ends; lining of the wing clear white, the feathers with central spaces of dusky-brown, which toward the edge become aggregated into a longitudinal patch; inner webs of the primaries with broad transverse spots of white, which reach nearly to the shaft; they are about thirteen in number on the longest quill. Feet yellow; base of the bill tinged with the same. Wing-formula, 2, 3–1, 4. Wing, 12.00; tail, 7.50; tarsus, 1.90; middle toe, 1.70; outer, 1.22; inner, 1.12; posterior, .77.

♀ (not _adult?_ 18,258, Fort Buchanan, New Mexico; Dr. Irwin). Above continuous umber-drab, growing gradually lighter posteriorly, the tail being pale drab; no transverse bars (except a few concealed obsolete ones on back and secondaries), but all the feathers faintly bordered with paler rusty-brown, these edgings being on upper tail-coverts almost white. Tail tipped with creamy-white, and with many transverse spots or broad bars of the same on inner webs, outer feather irregularly skirted with the same, and all decidedly paler than the ground-color along their edges. Head as in the male, but forehead white, and superciliary stripe more continuous. Breast and abdomen with longitudinal lanceolate or cuneate streaks of dark vandyke-brown; patch of same on flanks more continuous than in the male; axillars unvariegated clear dark vandyke-brown; longest primary with eleven transverse spots of white; posterior outer face of tibiæ with sagittate spots of dark brown. Wing-formula, 2, 3–1, 4. Wing, 14.25; tail, 8.00; tarsus, 2.10; middle toe, 2.00.

_Juv._ (♂, 32,207, South Fork of the Platte River, July 19, 1838; C. S. McCarthy). Above darker umber than the last, each feather distinctly bordered terminally with rusty-ochraceous. Beneath with a deeper cream-colored tinge, streaks blacker; flank-patch more conspicuous and uniform; axillars unvariegated dusky. Wing-formula, 2, 3–1=4. Wing, 13.25; tail, 7.25.

HAB. Western division of North America, eastward to Illinois; Oregon to Lower California, and Texas. Localities: Texas, San Antonio and Eagle Pass (DRESSER); Arizona (COUES).

The different stages of plumage are in this by no means so well defined as in other species, there being nearly the same general appearance in all. There is, also, very little variation in different specimens of the same age. No. 8,504, (♀, Dalles, Oregon; Dr. George Suckley) has the black markings on the sides of the breast more circular, and the vandyke-black of the axillars with a few circular white spots on the edges of the feathers. Wing, 14.50; tail, 8.40. Nos. 17,204 (♀, San José, Lower California; John Xantus, January, 1860) and 18,258 (♂ ? Fort Buchanan, N. M.) have the upper surface almost perfectly continuous grayish-drab, the first absolutely unvariegated by markings, though the feathers fade a little on edges. Beneath, the white is very pure; the streaks are numerous, sharply defined and longitudinal. Wing, 13.25; tail, 7.50 (17,204).

The American Lanner Falcon is so very closely related to the Lanners of Europe and Asia (var. _lanarius_ and var. _jugger_) that it is very difficult to indicate the differences which separate them. The two Old World forms above named are more unlike each other than they are from the two American races; the var. _jugger_ differing from _mexicanus_ apparently only in larger size; and the var. _lanarius_, more like _polyagrus_ than it is like either _jugger_ or _mexicanus_, differs from _polyagrus_ mainly in the greater amount of white on the plumage, this imparting a lighter aspect to the pileum, and causing a greater development of the light spots on the outer webs of the primaries and rectrices.

The var. _polyagrus_, compared with var. _lanarius_, is much darker, having, at all ages, the crown uniformly brown, with darker streaks, instead of having these streaks upon a white ground. The “mustache” is more distinct in the American bird, while in the European the bands on the tail are much more distinct, and the spots forming them are on the outer webs, as well as on the inner, instead of on the latter alone; the dark bars between the light spots are in the American bird much narrower and more numerous, and in the young the light ones come to the edge of the web, instead of being enclosed within the dark color. Two very young birds (i.e. in first perfect plumage) appear almost identical until closely examined, the chief differences being a lighter tint to the crown in the European, and heavier dark stripes on the breast, besides the peculiar character of the tail-spots, which are always distinctive. In shades of color, there is not the slightest difference.

I have seen no specimen of any of the Old World forms in the plumage corresponding to that transversely barred above, described here as the adult, though figures of the adult _lanarius_ indicate a very similar plumage. The series of the latter race at my command is unfortunately limited to a very few immature specimens. One marked “ad.” (56,051, Hungary; Schlüter Coll.) measures as follows: Wing, 14.50; tail, 8.00; culmen, .83; tarsus, 1.90; middle toe, 1.80. Its colors are as described in the synopsis (p. 1429) for the young bird.