ROSTRHAMUS SOCIABILIS. 
Blue Kite. Everglade Kite. So-for-fun-i-kar'. 
“Hei-petotheres sociabilis Vieillot, Nouv. Diet., xviii, 318 (1817).” Bostrhamus sociabilis Baird, Birds N. Am., p. 38,1858. 
DESCRIPTION. 
Plate I, Male; Plate Y, Female and Eggs. 
Form rather slender, upper mandible long and hooked, wings and tail long, the latter slightly emarginatc. 
Tarsi moderate. Claws long but not strongly curved. 
Color. Adult Male. —Forehead, cheeks, upper part of throat, middle of back, tertiaries, secondaries, prima¬ 
ries and middle of tail"dull black; brightest on the wings and tail, dullest on the head. Lower part of throat and 
entire under surface of body, including under wing-coverts, very dark brown. Upper wing-coverts, shoulders and 
scapularies, reddish brown. Occiput and hind neck, pale slaty blue; this latter color pervades the surface of all 
the feathers, with more or less intensity, excepting those of the secondaries, quills and tail. Upper and under tail- 
coverts, basal portion of one-half of four outer and one-third of the remainder of all the other tail feathers, pure 
white. Under surface of the primaries, and that portion of under surface of tail corresponding to the black 
above, glaucous; the former obscurely mottled with white. The terminal portion of the white ends abruptly on 
the lower surface of the tail, but above it is preceded by a bar of pale reddish brown, which is broadest on the 
outer feathers. The tail is rather broadly tipped with the same color; the tertiaries, secondaries, and some of the 
inner quills are also slightly edged with it. The tibiae are dark reddish brown. Cere, feet, and tarsi, naked spaces 
before the eyes, commissure and base of lower mandible, bright orange. Remainder of the bill and the claws 
black. 
Adult Female. — Narrow line on the forehead, upper part of throat and under tail-coverts, yellowish white; the 
two former, with the shafts of the feathers, black. Entire upper and under surface of body, upper portions of 
wings, under wing-coverts and tibiae, brown; top of head, shoulders, both wing-coverts, inner edges of wing 
feathers, under surface of body and tibiae, striped, barred and spotted with rufous; brightest on the shoulders and 
under wing-coverts. The tail, edges of primaries, secondaries and tertiaries, are colored as in the male; the pale 
brown edging also extends to the feathers of the back. Under surface of wings glaucous, with broad bands of 
yellowish white. Occiput and hind neck obscurely colored with bluish. Cere, naked spaces before the eyes, edges 
of commissure, base of lower mandible, feet and tarsi, yellow. Remainder of the bill and the claws, black. 
Young Male. — Colored much as the adult female, with the throat whiter and the stripes on the under surface 
lighter and broader; stripes over the eyes and spaces on the sides of the neck, yellowish white. Cere and other 
portions, that are yellow in the female, are pale orange. Iris, in all stages of plumage, bright ruby. 
Observations. — This species resembles the marsh hawk in form and general coloration, but may readily be 
distinguished from it by the long and curved upper mandible. The slaty blue seen on the adult male resembles 
that of some species of herons. A skin of an adult female of this species, from the Smithsonian Collection (No. 
53081), taken in Buenos Ayres, and kindly loaned me by Prof. Baird, does not differ essentially from those taken in 
Florida. It is, perhaps, a little darker, and the bill is a trifle broader. 
LIST OF MEASUREMENTS. 
No. 
Locality - . 
Age. 
Sex. 
Date. 
Length. 
Breadth. 
WING. 
Tail. 
Bill. 
Tarsus. 
Remarks. 
5194 
Everglades, Fla.* 
Adult 
$ 
Mch. 1,1871. 
1800. 
45 00 
14-50 
7-50 
1-04 
2-40 
Breeding. 
5195 
.“/ | 
Y.ofyr. 
$ 
“ “ “ 
16-00 
44-25 
13-50 
7-00 
■95 
1 75 
Very light colored. 
5196 
/ « , « 
Adult 
$ 
fe# “ 
17-00 
44-25 
1400 
7-50 
100 
2-00 
5226 
“ 
% 
? 
“ 3 “ 
17-00 
44-75 
14-00 
7-50 
TOO 
T43 
Breeding. 
5385 
SB 
? 
“ 25 “ 
1710 
45-90 
14-50 
7-50 
•90 
1-55 
Breeding. 
5386 
“ 
m 
$ 
* 
16-50 
44-00 
14-00 
6'75 
TOO 
215 
Very small. 
5387 
1 
Y.ofyr. 
s 
“ “ 
16-00 
44-25 
15-50 
700 
•95 
2-00 
53081 
Conchizos, Bu. Ay. 
Adult. 
¥ 
Sept., 1867. 
1700 
— 
14-00 
7-50 
-95 
1-80 
Skin. 
