SWALLOW-TAILED HAWK. 
275 
SWALLOW-TAILED HAWK FALCO FURCATUS. 
Plate LI. Fig. 3. 
Linn. Syst. 129. — Lath. i. 60. — Hirundo maxima Peruviana avis preedatoris calca- 
ribus instructa, Feuillee, Voy. Peru , tom. ii. 33. — Catesb. i. 4. — Le Milan de la 
Caroline, Priss. i. 418. — Puff. i. 221. — Turt. Syst. 149. — Arct. Zool. p. 210, 
No. 108. — Peale's Museum , No. 142. 
EL AN US FURCATUS. — Savigny.* 
Le Milan de Caroline, Cuv. Reg. Anim. i. p. 322 Elanus furcatus, Ponap. Synop. 
p. 31. — Nauclerus furcatus, Vig. Zool. Journ. No. VII. p. 387 Less. Man. 
d' Ornith. i. p. 101 The Swallow-tailed Hawk, Aud. pi. 72; Orn. Piog. i. 
p. 368. 
This very elegant species inhabits the southern districts of 
the United States in summer ; is seldom seen as far north as 
Pennsylvania, but is very abundant in South Carolina and 
* The characters of the birds composing this genus are, — general form of 
less strength than most of the Falconidoe ; bill, rather weak ; tooth, little seen ; 
the tarsi, short, thick, reticulated, and partly feathered in front ; wings, greatly 
elongated ; timorous, and, like the Kites, excel in flight, circling in the air. 
Mr Vigors has formed a genus, Nauclerus , of this and a small African species, 
dividing them from Elanus, where they were placed by most prior ornitho- 
logists. In these two birds, the tail is forked to a great extent ; while, in the 
others, it only commences to assume that form, and, in one, is altogether 
square. The claws also are not circular underneath, as in the others, to 
which Mr Vigors would restrict Elanus. The wings of the two birds, how- 
ever, shew considerable difference ; the quills, in the American, being abruptly 
emarginated, the third longest ; in the African, the second is longest, and only 
a slight emargination on the two first. Altogether we are not quite satisfied 
with the distinctions. I have for the present retained Elanus , notwithstanding 
the differences that do exist between some of its members. 
According to Audubon, they feed chiefly on the wing ; and having pounced on 
any prey upon the ground, rise with it, and devour it while flying. “ In calm 
and warm weather,” he remarks, ‘ k they soar to an immense height, pursuing the 
large insects called Musquito Hawks, .nd performing the most singular evolutions 
that can be conceived, using their t il with an elegance peculiar to them- 
selves.” They thus shew a manner o° feeding entirely different from most 
birds of prey, which generally retire to some distance, and devour in quiet on the 
ground. There are some partly insectivorous Hawks — Penis, for instance — which 
seize and devour the insect during flight ; but larger prey is treated at leisure. 
