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

304 BULKETIN 133, UNITED STATES NATIONAL, MUSEUM
These flycatchers run about freely on the ground, stopping ab-
ruptly to throw up the head, so that they frequently suggest small
thrushes. At other times they rest on clods of earth, bushes, or
fence posts, from which they dart out at passing insects. Like
Taenioytera irwpero^ they suggest in many of their mannerisms the
bluebirds {Sialia) of North America. The crenulated lobe encir-
cling the eye is easily seen in females, while in males, in which it is
larger, its extent and light color produce an effect that is almost
uncanny. During the breeding season males frequently rise 3 or 4
meters in the air, to whirl over and descend head first, with rapidly
vibrating wings that produce a white halo about the body. Occa-
sionally one in the same display describes erratic parabolas in the
air, that reveal its contrasted colors to the utmost. Not content
with these conspicuous displays, it attempts song, a squeaky effort
barely audible at 50 meters. At other seasons the birds are wholly
silent.
On November 24 a female was seen near Roca carrying material
for nest lining, while at Ingeniero White, the port of Bahia Blanca,
two or three broods of fully grown young were seen December 13.
These last uttered low, squeaky calls.
The species is known locally as pico plato^ or more rarely ojo plato,
misnomers both since bill and eye are yellow. An adult male, taken
July 10, had the bill straw yellow, tipped faintly with duslcy ; rosette
about eye baryta yellow; iris barium yellow; tarsus and toes black.
A female, shot July 23, had the maxilla and tip of mandible bone
brown, becoming blackish at extreme tip; sides of maxilla, behind
and below nostril, and base of mandible chartreuse yellow; iris
vinaceous buff, with spots and mottlings of a darker color; rosette
about eye deep olive-buff; tarsus and toes black.
LICHENOPS PERSPICILLATA ANDINA Ridgway
Lichenops perspicillatus andinus Ridgway, Proc. U. S. Nat. Mus., vol. 2,
May 22, 1879, p. 483. (Santiago, Chile.)
An adult male silverbill shot at Zapala, Neuquen, on December 9,
1920, is representative of the present race, as the white wing patch
is restricted by encroachment of black, especially on the outer webs
of the primaries, and the wing has a measurement of 96.2 mm.
Females of the two races of Lichenops appear indistinguishable in
color, though in andina they average somewhat larger than in true
perspicillata. The difference is slight and measurements overlap, so
that many specimens of this sex, taken alone, may not be certainly
identified.
On December 8 and 9, 1920, these birds were fairly common in
areas where water offered them a suitable haunt. Extensive tracts