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

342 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
their wings in an endeavor to entice females to examine the proposed
nest site or circled about near by. Their broken, warbling song Avas
heard continually. Though apparently mating, the two taken were
not yet in breeding condition, and two nest holes that I examined
September 9 were empty. The species was recorded west to Kilometer
110. The white rump is a field mark prominent in flight. At
San Vicente, Uruguay, from January 27 to February 3, families of
young recently from the nest were recorded, while near Lazcano,
Uruguay, from February 3 to 9, the birds had gathered in flocks
which contained from 10 to 100 individuals that rested on fence
wires or circled low over the fields. The birds were so abundant
here that hundreds frequently were observed during a day.
HIRUNDO ERYTHROGASTRA Boddaert
Hlrundo erpthrogaster Boddaekt, Tabl. Planch. Enl., 1783, p. 45.
(Cayenne.)
On the evening of September 24, 1920, when near the Laguna
Wall, in the Chaco, 200 kilometers w^est of Puerto Pinasco, Para-
guay, I was delighted to distinguish the graceful forms of several
barn swallows among the members of a flock of Pygochelidon that
came circling over the marshes in search of a secure resort to spend
the night. The L ngua Indian who was with me distinguished the
specimen that I collected, an adult female, from other swallows as
Tneni a sakh sa heht Ml wa nah. In the southern part of their winter
range, barn swallows were not common as subsequently I saw
them on only three occasions, at Puerto Pinasco, near the Rio
Paraguay, September 30; near Lezama, Buenos Aires (from a
train), October 19, and near Lavalle, Buenos Aires, November 15.
Two were seen on each of these dates.
ALOPOCHELIDON FUCATA (Temminck)
Hirundo fucata Temminck, Nouv. Rec. Planch. Col. Ois., vol. 4, 1838, pi.
161. (Brazil.)
This species was observed on August 23 and 24 near my hotel in
Formosa, Formosa, under such conditions that it could not be collected.
On one occasion a pair alighted on the ground to waddle
about with sidling steps, picking up bits of sand. A female shot
March 28, 1921, from a flock of Pygochelidon. at Tunuyan, Mendoza,
was the only one taken. On the wing this bird resembles a rough-
wanged swalloAv {Stelgidopteryx)
.
Chubb ^^ has described a subspecies of this bird from Mount
Roraima, British Guiana, as A. f. roraiTnae^ on the basis of brighter
coloration of head and throat, paler dorsal surface, and smaller size
saBuU. Brit. Orn. Club, vol. 40, .Tune 30, 1920, p. 155.