(RUSH-LOVING SPINE-TAIL.)
+Synallaxis melanops+, _Burm. La-Plata Reise_, ii. p. 470 (Mendoza).
+Phloeocryptes melanops+, _Scl. et Salv. Nomencl._ p. 63;
_Durnford, Ibis_, 1877, p. 179 (Buenos Ayres), et 1878, p. 396
(Central Patagonia); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 206
(Bahia Blanca).
_Description._--Above, forehead brown, crown blackish, broad
superciliaries buffy white; upper half of back black, marked with a
few grey stripes; lower back and rump, also sides of head and neck,
light brown; wings blackish, mottled with light chestnut on the
coverts; and a broad band of the same colour occupying the basal
half of the wing-feathers; tail blackish, the two middle feathers
brownish grey, the others slightly tipped with the same colour;
beneath white, more or less tinged on the throat, flanks, and under
tail-coverts with pale brown; under wing-coverts fulvous; bill and
feet pale horn-colour: whole length 5·8 inches, wing 2·3, tail 1·6.
_Female_ similar.
_Hab._ Chili, Patagonia, and Argentina.
This is one of our few strictly migratory species in the family
_Dendrocolaptidæ_. Probably it winters in South Brazil, as in the
northern parts of the Argentine country it is said to be a summer
visitor. On the pampas it appears in September, and all at once becomes
very abundant in the rush-beds growing in the water, where alone it is
found. The migration no doubt is very extensive, for in spring I found
it abundant in the rush-beds in the Rio Negro valley, and Durnford met
with it much further south on the river Sanguelen, a tributary of the
Chupat. Migratory birds are, as a rule, very little given to wandering;
that is to say, they do not go much beyond the limits of the little
coppice, reed-bed, or spot of ground which they make their summer home,
and this species is no exception. It spends the warm season secluded in
its rush-bed: and when disturbed flies with great reluctance, fluttering
feebly away to a distance of a few yards, and then dropping into the
rushes again, apparently quite incapable of a sustained flight. How
a bird so feeble on the wing, and retiring in its habits, is able to
perform a long, annual migration, when in traversing vast tracts of
open country it must be in great peril from rapacious kinds, is a great
mystery. No doubt many perish while travelling; but there is this
circumstance in their favour: an incredible number of birds of various
kinds, many as weak and exposed to attack as the _Phloeocryptes_,
migrate simultaneously; Hawks are very thinly scattered along their
route, and as a rule these birds feed only once or twice a day, if the
meals are large enough to fill the stomach, so that while the Hawk is
inactive, digesting his meal, thousands of migrants have sped by on
their journey and are beyond his reach for ever.
This Spine-tail seldom ventures out of its rush-bed, but is occasionally
seen feeding in the grass and herbage a few yards removed from the
water. Its language is peculiar, this being a long cicada-like note,
followed by a series of sounds like smart taps on a piece of dry
wood. It frequents the same places as the small Many-coloured Tyrant
(_Cyanotis azaræ_), and these little neighbours, being equally
inquisitive, whenever a person approaches the rushes often emerge
together, one uttering wooden-sounding creaks and raps, the other liquid
gurgling notes--a little brown bird and a little bird with many bright
colours, both, in very different tones, demanding to know the reason of
the intrusion.
The nest is a very wonderful structure, and is usually attached to three
upright stems; it is domed, oval-shaped, about nine inches deep, and
the small circular aperture which is close to the top is protected by a
sloping tile-like projection. It is built of tough grass-leaves, which
are apparently first daubed with wet clay and then ingeniously woven in,
with the addition, I think, of some kind of mucilage: the whole nest is,
when finished, light but very strong, and impervious to wet. Until the
rushes die and drop the nest remains securely fastened to them, and in
winter affords a safe and comfortable retreat to the small reed-frogs,
of which sometimes as many as three or four are found living in one
nest. The interior is very thickly lined with feathers; the eggs are
three, pear-shaped, and a bright, beautiful blue colour, sometimes with
a slight greenish tinge.
The bird is so abundant in extensive marshes that I have on several
occasions, during a day's ramble, found as many as forty or fifty nests,
sometimes a dozen or more being placed close together, but I have never
taken more than three eggs from one nest. I mention this because I have
seen it stated that four or five eggs are sometimes found.
I trust that no reader of this sketch imagines that I robbed all the
eggs contained in so many nests. I did nothing so barbarous, although
it is perhaps "prattling out of fashion" to say so; but with the
destructive, useless egg-collecting passion I have no sympathy. By
bending the pliant rushes downwards the eggs can be made to roll out
into the hand; and all those which I thus took out to count were, I am
glad to say, put back in their wonderful cradles. I had a special object
in examining so many nests. A gaucho boy once brought me a nest which
had a small circular _stopper_, made of the same texture as the body of
the nest, attached to the aperture at the _side_, and when swung round
into it fitting it as perfectly as the lid of the trap-door spider fits
the burrow. I have no doubt that it was used to close the nest when the
bird was away, perhaps to prevent the intrusion of reed-frogs or of
other small birds; but I have never found another nest like it, nor have
I heard of one being found by any one else; and that one nest, with its
perfectly-fitting stopper, has been a puzzle to my mind ever since I
saw it.