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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 319
Uruguay, February 7 and 8, belonged to the present species, but no
specimens were collected for identification.
It is probable that there are two forms of subcristata in the range
as outlined in the opening paragraph above. The single specimen
secured from west of Puerto Pinasco and a few others seen from the
Chaco are paler below than birds from the Province of Buenos
Aires. Birds that in bright coloration resemble those of the south
were also secured at lias Palmas and Resist encia. It is possible that
the pale birds represent a resident form of the Chaco and that the
brighter ones are winter migrants from the south.
>S. munda is so similar to &. KuhcHstata that it would appear that
the two should stand as subspecies of one form. However, west of
Puerto Pinasco, Paraguay, on the ranch known as Kilometer 80, I
found suhc7istafa and muiula ranging in the same forests without
evidence of intergradation, so that they must be considered specifi-
cally distinct. As S. inornata was taken there also, three distinct
species of Serpophaga were found at this point.
Serpophaga suhcHstata is one of the familiar species of the forested
regions and brushy areas in the Chaco, that on the pampas
inhabits groves about the estancias, and in the more arid south is
found in heavy stands of Baccharis and Salix along the larger
streams. Though undoubtedly a flycatcher, it is so sprightly and
vivacious in its movements that in life it gives little suggestion of
its tyrannine affinities. In fact, as the birds flit and hop about
among the twigs, often calling or singing excitedly, they bear a
striking resemblance to warblers. During winter they Avere found
constantly with little bands of other little birds that ranged the
forests and came around without fear to inspect me, often hopping
out almost within reach. Both sexes sang frequently, a fact that I
established by collecting specimens, but the notes of males were
louder than those of the opposite sex. The entire song may be repre
sented as chois chois chee chee chee chee-ee-ee-ee^ a few twittering
notes followed by a hard trill, of which the first part was frequently
omitted.
The first young bird seen, a male not quite grown, was taken December
29, near Victorica, Pampa. Other juvenile birds were recorded
at San Vicente, Urugua3% January 31, and Rio Negro, Uruguay,
February 14, In juvenal plumage subcristata is washed with
brown above, especially on the upper tail coverts, and has the wing
bars light-pinkish cinnamon instead of whitish. Beneath the birds
are whitish, and the black and white markings found in adults in
the crown are lacking. An adult female shot at Rio Negro, Uruguay,
Februar}^ 19, is in fall molt.
The bill and tarsus in this species are black.