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

306 BULUETIISr 133, UNITED STATES NATIONAL, MUSEUM
rapidly for a considerable distance. With its evident predilection
for the vicinity of large animals, one may wonder if, hundreds and
thousands of years ago, Machetornis was as familiar with the giant
ground sloths and glyptodons that ranged then through these same
regions as it is now with the stock introduced by man.
When not in company with cattle, Machetornis frequently ran
about on the aquatic plants that covered the surface of small lagoons,
where the long legs came in play in enabling the birds to step over
interstices between the leaves of the plants. With the coming of
September mating activities began, and the flycatchers pursued one
another with snap and vigor, uttering high-pitched, squeaky calls
and rattling their wings. Occasionally one rested in a tree top to
utter a soft song swee see dee^ a low effort that, though simple, was
pleasing.
The Anguete Indians called this bird yeht tin a has goohh.
MUSCISAXICOLA MACULIROSTRIS d'Orbigny and Lafresnaye
Muscisaxicola macuUrostris cI'Oebigny and Lafresnaye, Mag. Zool., 1S37,
cl. 2, p. 66. (La Paz, Bolivia.)
The 10 specimens taken were secured as follows: General Roca^
Rio Negro, November 29, 1920, adult female; Zapala, Neuquen,
December 8, adult female; Mendoza, Mendoza (altitude, 850 meters),
March 13, 1921, male and female; Potrerillos, Mendoza (1,500 to
1,800 meters), March 16, IT, 18, and 19, four males and two females.
The two adults secured in northern Patagonia in summer are breeding
birds in slightly worn plumage. The series secured in the Province
of Mendoza are all in fresh fall dress, and may be migrants
come from the south. Three specimens seen from Galea, Peru are
duller on the abdomen, and grayer on the sides of the head and neck
than birds from Argentina, a difference that though slight seems
distinct. With specimens from the type locality for comparison, it
is probable that two forms may be recognized.
Following are the dates on which M. mac'lpvostris was recorded:
General Roca, Rio Negro, November 29, 1920; Zapala, Neuquen,
December 8 ; Mendoza, Mendoza, March 13, 1921 ; Potrerillos, Men-
doza, March 15 to 19 ; Tunuyan, Mendoza, March 25.
Those seen on their breeding grounds were found among low
bushes on sandy or gravelly hillsides. Those noted in winter chose
similar haunts, usually on sloping flats near streams, or on hill-
sides above water, where scattered bushes offered cover but left the
ground bare in between. At this season they were found in little
parties of two or three that ran alertly about on the ground, or
rested for a few minutes in the tops of bushes. Passing insects were
secured by a quick spring in the air, while others were picked up
in the scanty herbage. Short, low flights, near the ground, revealed