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

424 BULLETIN 133, UNITED STATES NATIONAL MUSEUM
on back, wing edgings, and sides than others seen from Tucuman
and Salta, and may represent a geographic race not yet described.
Specimens taken at Tapia include adults in molt and a female in
Juvenal plumage which differs from the adult in being paler brown,
and much paler on sides and flanks.
These birds ranged in pairs or parties of five or six on the ground
among low bushes, in burns, or at the borders of fields or thickets.
When alarmed they flew up, with a flash of black and white from
the tail and a tilting flight, to perch in thickets sometimes 3 or 5
meters from the ground. Their light coloration made them conspicuous,
but they rested quietly without apparent fear to drop
back after a minute or two out of sight. Their call is an insistent
chipping note like that of a junco.
A male, taken April 7, had the maxilla dark mouse gray ;
edge of maxilla and mandible mustard yellow ; iris natal brown
tarsus and toes neutral •
;
cutting
gray. A juvenile individual had the bill
dull black with the cutting edges faintly marked with dull yellow.
AIMOPHILA STRIGICEPS DABBENEI (Hellinayr)
Zonotrichia strigicej)S dahbenei HELr^cAYR, Verb. Ornith. Ges. Bayern, vol.
11, 1912, p. 190. (Tapia, Tucuman.)
Two specimens were taken at Tapia, Tucuman, April 10, 1921, one
of which was prepared as a skeleton. Doctor Hellmayr in describing
the present form differentiated it from strigice'ps (type-locality
Santa Fe) on larger size, stronger bill, and darker brown stripes on
the side of the head. The specimens taken at Tapia are the only
ones that I have seen. The skin, an adult male, has the following
measurements: Wing, 72.6; tail, 78.3; culmen from base, 14; tarsus,
22 mm.
The generic relationships of this species have been in doubt. The
bird belongs without question in the supergeneric group entitled the
Zonotrichiae by Mr. Eidgway,-^ in which genera, in most cases, are
closely related. It is certainly not a Zonotnchia, in which Hellmayr
placed it provisionally, as it has the tail longer than the wing, a
different wing formula and a heavier bill, reasons that likewise
prevent its allocation in Brachyspisa. In general appearance, wing,
tail, and bill, it is closely similar to Aimophila rufescens, the type of
Aimopliila Swainson, differing from that bird structurally mainly
in its smaller more delicate feet. Although, as Mr. Ridgway has
indicated, Aimophila is a somewhat heterogeneous group, still it may
not be divided, and strigiceps may be placed in it without difficulty,
as has been done by Salvadori and Dabbene and others. As proof of
this the species runs readily to the genus Aimojjhila in Mr. Ridg-
way's key to the finches of North and Middle America.
23 Birds North and Middle America, vol. 1, 1901, p. 28.