_Campylorhynchus affinis_, XANTUS, Pr. A. N. Sc. 1859, 298 (Cape St.
Lucas).—BAIRD, Pr. A. N. Sc. 1859, 303; Rev. 100.—SCL. Catal.
1861, 17, no. 108.—ELLIOT, Illust. B. N. A. I, IV.—COOPER, Orn.
Cal. 1, 1870, 62.
SP. CHAR. Cap of head reddish-brown; the concealed centres of feathers
dusky. Rest of upper parts grayish-brown, all the feathers of body and
scapulars with broad central or shaft streaks of whitish edged with
black; the streaks irregular in outline, on some feathers nearly
linear, in others widening at intervals along the shaft. Outer webs of
the wing-feathers crossed by about seven rows of whitish semicircular
spots, with corresponding series of more circular ones on the inner
web. Tail-feathers black, all of them with a series of about eight
quadrate white spots on each web, which are alternate to each other,
not opposite, and extend from or near the black shaft to the edge; the
extreme tips of the feathers black; the two central feathers, however,
more like the back, with irregular mottling of grayish and black.
Upper tail-coverts barred transversely with black.
Under parts white, faintly tinged with rusty posteriorly; each feather
spotted with black, excepting on the immaculate chin. These spots are
rather larger and more quadrate on the jugulum, where they are
sometimes on the sides of the feathers (on one or both sides);
posteriorly, however, they are elongated or tear-shaped, and strung
along the shaft, one or two on each. On the crissum they are large and
much rounded, three or four on each longer feather. Legs rather dusky.
Bill lead-color, pale at the base below; iris reddish-brown. A broad
white stripe from bill over the eye and nape; edged above and below
with black; line behind the eye like the crown; cheek-feathers white,
edged with blackish.
Immature specimens exhibit a tendency to a whitish spotting in the
ends of the feathers of the cap. A very young bird does not, however,
differ materially, except in having the spots less distinct beneath,
the white streaks less conspicuous above, the white of the wings
soiled with rufous. Specimens vary considerably in the proportional as
well as absolute thickness and length of the bill; thus, No. 32,167
measures .80 from nostril to end of bill, instead of .60, as given
below for No. 12,965.
12,965. Total length, 7.50; wing, 3.30; tail, 3.40; its graduation,
.45; exposed portion of first primary, 1.42, of second, 2.15, of
longest, or fourth (measured from exposed base of first primary),
2.45; length of bill from forehead, .90, from nostril, .60; along
gape, 1.07; tarsus, 1.02; middle toe and claw, .90; claw alone, .25;
hind toe and claw, .76; claw alone, .35.
HAB. Only observed at Cape St. Lucas, Lower California.
This species is most nearly allied to _C. brunneicapillus_; the most
apparent difference at first sight being in the greater concentration
of black on the throat and jugulum in _brunneicapillus_, and the much
smaller size of the remaining spots on the under parts, with the
decided light-cinnamon of the posterior portion of the body. The outer
and central tail-feathers alone are marked as in _C. affinis_, the
intermediate ones being entirely black, with the exception of a white
subterminal band.
This is one of the most characteristic birds constituting the isolated
fauna of Cape St. Lucas. Like nearly all the species peculiar to this
remarkable locality, it is exceedingly abundant, breeding in immense
numbers. It has not yet been detected elsewhere, though it may
possibly be found on the Lower Colorado.
HABITS. This recently described species was first discovered by Mr.
Xantus, and has, so far as is known, a somewhat restricted locality,
having been met with only at the southern extremity of Lower
California, where it is an exceedingly abundant bird. Mr. Xantus has
published no observations in regard to its habits, which, however, are
probably very nearly identical with those of the more common species.
From the brief memoranda given by him in the general register of his
collections, made at Cape St. Lucas, we gather that their nests were
built almost exclusively in opuntias, cacti, and the prickly pear, and
were generally only four or five feet from the ground, but
occasionally at the height of ten feet.
The nests are large purse-shaped collections of twigs and coarse
grasses, very similar to, and hardly distinguishable in any respect
from, those of the more northern species. The eggs vary from 1.05 to 1
inch in length, and from .65 to .70 of an inch in breadth, and have a
reddish-white ground very uniformly dotted with fine markings of
reddish-brown, purple, and slate.