Bulletin - United States National Museum - si-pddr - Smithsonian ...

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 203
sus, 15.2 mm. Specimens of griseus from the type locality are not
at hand, but a bird from the Para River is assumed to represent the
typical form. The bird from Paraguay is very similar to it in size,
and in color pattern differs only in having slightly heavier black
streaks on the under tail coverts. For the present, therefore, Caprimulgus
cornutus Vieillot must be considered as a synonym of Nyctihius
g. griseus. Examination of a small series of potoos seem to show
that, like many of the Caprimulgidae, they have two types of coloration,
one dark and more or less rufescent, and the other pale and
gray, a fact that makes the proper designation of geographic races
difficult. Skins from Peru and Ecuador referred doubtfully by Mr.
Ridgway to cornutus^- are larger and darker than the specimens
mentioned from Brazil and Paraguay. Whether they represent an
unnamed form or whether they should be referred to the bird from
Panama, which they resemble closely, it is not possible at present to
decide.
The female shot September 30 in Paraguay had the bill black;
margin of mandible vinaceous buff; iris deep chrome; tarsus and
toes drab.
Family CAPRIMULGIDAE
THERMOCHALCIS LONGIROSTRIS (Bonaparte)
Caprimulgus longirostrls Bonaparte, Journ. Acad. Nat. Sci. Philadelphia,
^ vol. 4, pt. 2, no. 12, 1825, p. 384. (Brazil.")
South of Tunuyan, Mendoza, on March 27, 1921, a male of this
species flushed with a chattering, whistling call among low bushes
on a sandy hill slope, and darted swiftly and erratically away to
drop to fresh cover. As it rose a second time it was secured. The
large white wing patches give a resemblance to Chordeiles when the
bird is on the wing. Another was seen April 8, near Tapia, Tucuman,
in dry forest on a steep rocky slope.
On an evening in mid-October one of these birds flew from tree
to tree along the Avenida de Mayo, in the heart of the business
district of Buenos Aires, an individual that had become bewildered
during migration. At Lavalle on November 12, 1920, I was taken
to view a curious bird, described as " possessing a moustache like
a Christian," that had been captured in a garden about three weeks
ago, to find that it was the present species. According to popular belief
a feather of this bird was a potent love charm, and the fortunate
owner of the bird had been charging 10 centavos for a view of the bird
to those of the populace whose curiosity regarding the anomalous
creature was uncontrollable, while feathers retailed at a peso each,
^ Birds North and Middle America, vol. 6, 1914, p. 587.
8» Bonaparte described his bird as from South America without knowu locality, but
Brabourne and Chubb, Birds of South America, 1912, p. 101, cite " Brazil " without
comment.