_Elanus_, SAV. 1809. (Type, _Falco melanopterus_, DAUDIN.)
_Milans_, BOIE, 1822.
GEN. CHAR. Bill rather small and narrow, the tip normal; commissure
moderately sinuated; upper outline of lower mandible greatly arched,
the height at base less than half that through middle; gonys almost
straight, declining downward toward tip. Nostril roundish, in middle
of cere. Tarsus and toes (except terminal joint) covered with small
roundish scales; under surface of claws just perceptibly flattened;
sharp lateral ridge on middle claw very prominent; a very slight
membrane between outer and middle toes. Second quill longest, third very
slightly shorter; first just exceeding fourth; second and third with
outer webs slightly sinuated; inner web of first emarginated, of second
sinuated. Tail peculiar, emarginated, but the lateral feather much
shorter than the middle, the one next to it being the longest.
[Illustration:
=5895.= ½
=5895.= ½
=5895.= ¼
_Elanus leucurus._]
The species of this well-marked genus are confined to the tropical and
subtropical portions of the world, and appear to be only two in number,
of which one is cosmopolitan, and the other peculiar to the Old World.
Species and Races.
COMMON CHARACTERS. Above pearly ash, becoming white or whitish on the
head and tail, with a large black patch covering the lesser-covert
region. Lower surface continuous pure white; a black spot on front of,
and partly around, the eye.
1. =E. leucurus.= A large black patch on the lining of the wing, in
the region of the primary coverts. First quill very much shorter
than the third; second quill longest.
Black patch on lining of the wing restricted to the primary
coverts; lesser coverts, on outer surface, not conspicuously
bordered anteriorly with white.
Above deep bluish-ash, with the inner webs of the secondaries
appreciably paler, sometimes abruptly white. Wing, 11.60–12.65;
tail, 6.80–7.80; culmen, .65–.80; tarsus, 1.20–1.50; middle toe,
.94–1.20. _Hab._ Tropical and subtropical America …
var. _leucurus_.
Above pale ash, with the inner webs of the secondaries
hardly, or not at all, appreciably paler than the outer.
Wing, 11.00–12.50; tail, 6.20–7.00; culmen, .70–.77; tarsus,
1.10–1.66; middle toe, 1.05–1.08. _Hab._ Western Australia …
var. _axillaris_.[71]
Black patch on the lining of the wing extending over the whole of
the lesser coverts; lesser coverts, on the outside, conspicuously
bordered anteriorly with white.
Similar to var. _axillaris_, except as above. Wing, 11.75–12.30;
tail, 6.30–7.00; culmen, .75–.80; tarsus, 1.10–1.40; middle toe,
1.15–1.25. _Hab._ Southern Australia …
var. _scriptus_.[72]
2. =E. cæruleus.= No black on lining of the wing. First quill
usually longer than the third, never very much shorter; second
longest. Colors darker than in _E. leucurus_.
Wing, 12.00; tail, 6.10; culmen, .75; tarsus, 1.25; middle toe,
1.20. No ashy tinge on side of breast. _Hab._ Southern Europe and
North Africa …
var. _cæruleus_.[73]
Wing, 9.50–10.70; tail, 5.40–5.75; culmen, .65–.70; tarsus,
1.05–1.10; middle toe, 1.00–1.10. Sides of the breast strongly
tinged with ashy. _Hab._ Southern Africa and India …
var. _minor_.[74]
Elanus leucurus (VIEILLOT).