_Turdus nanus_, AUD. Orn. Biog. V, 1839, 201, pl. cci.—BAIRD, Birds
N. A. 1858, 213; Rev. Am. B. 1864, 15.—SCLATER, P. Z. S.
1859.—IB. Catal. 1861.—DALL & BANNISTER.—COOPER, Birds Cal., p.
4. _Turdus pallasi_, var. _nanus_, RIDGWAY, Rep. Kings Exped. V,
1872. _? Turdus aonalaschkæ_, GMELIN, S. N. I, 1788, 808. _??
Muscicapa guttata_, PALLAS, Zoög. Rosso-Asiat. II, 1811, 465.
SP. CHAR. Above with the clear dark olive of _swainsoni_, but this
even purer and more plumbeous. Upper tail-coverts (but not lower part
of rump) becoming more rufous, the tail abruptly darker, richer, and
more _purplish_-rufous, approaching to chestnut. The clear olive of
the neck passes into brownish-_plumbeous_ along sides; pectoral spots
more sparse and less pure black than in _T. pallasi_. The white
beneath is of an almost snowy purity, appreciably different from the
cottony-white of _T. pallasi_. Wing, 3.30; tail, 3.00; bill, .36;
tarsus, 1.07.
A very tangible and constant character possessed by this bird is the
more slender and depressed bill, as compared with that of _T.
pallasi_. Specimens vary only in intensity of colors; these variations
very limited, and corresponding with those of _T. pallasi_. In all
cases, however, their precise pattern and peculiar distribution is
retained.
HAB. Western Province of North America, eastward from Kodiak to Cape
St. Lucas. Arizona, COUES.
HABITS. This small race of the Hermit Thrush was first noticed by Dr.
Pickering, and described by Mr. Audubon from an imperfect skin. It has
since been obtained abundantly on the Pacific slope, and Mr. Ridgway
procured a specimen as far east as the East Humboldt Mountains, which
he considers its eastern limit.
In its habits it is said to be, like _T. pallasi_, almost exclusively
terrestrial. Dr. Heermann mentions finding it abundant in California,
and breeding among the stunted oaks covering the sand-hills of San
Francisco. Dr. Coues found it in Arizona, but speaks of it as rare and
migratory, occurring chiefly in spring and autumn, and as a shy and
retiring species. Dr. Cooper, in his Report on the Birds of
California, describes it as shy and timid, preferring dark and shady
thickets, feeding chiefly on the ground, running rapidly, and
searching for insects among the leaves.
Near San Diego they began to sing about the 25th of April. The song,
consisting of a few low ringing notes, resembles that of Wilson’s
Thrush (_T. fuscescens_), and also that of _T. ustulatus_, but is not
so loud. Their note of alarm is a loud and ringing chirp, repeated and
answered by others at a long distance.
At Santa Cruz, on the first of June, Dr. Cooper met with several of
their nests, which, though probably erroneously, he supposed to belong
to the Dwarf Hermit Thrush. They were all built in thickets under the
shade of cottonwood-trees. Each nest was about five feet from the
ground, and all contained eggs, from two to four in number, in
differing stages of incubation. The nests were built of dry leaves,
roots, fibres, grasses, and bark, without any mud, and were lined with
decayed leaves. Their height and external diameter measured 4 inches.
The diameter of the cavity was 2½ inches and the depth 2¼. The eggs
measured .90 by .70 of an inch. They are of a pale bluish-green,
speckled with cinnamon-brown, chiefly at the larger end.
The nest, supposed to be of this species, supplied by Dr. Cooper, is
large for the bird; constructed of a base loosely made up of mosses,
lichens, and coarse fibres of plants. It is a strong and compact
structure of matted leaves, put together when in a moist and decaying
condition; with these there are interwoven roots, twigs, and strong
fibres, surrounding the nest with a stout band and strengthening the
rim. In fact, it corresponds so well—as do the eggs also—with those
of _T. ustulatus_, that it is extremely probable that they really
belong to that species. The only observable difference is the absence
of the _Hypnum_ mosses characteristic of northern _ustulatus_.
Dall and Bannister mention in their list of Alaska birds that the
species is not common there. It was also taken at Sitka and Kodiak by
Bischoff.
The fact that this thrush builds its nest above the ground, and lays
spotted eggs, if verified, would at once warrant our giving it
independent rank as a species, instead of considering it as a local
race of _pallasi_.
Turdus pallasi, var. auduboni, BAIRD.