(TREE-MARTIN.)
+Progne tapera+, _Scl. P. Z. S._ 1872, p. 606 (Buenos Ayres); _Scl.
et Salv. Nomencl._ p. 14; _Durnford, Ibis_, 1877, p. 168 (Buenos
Ayres); _White, P. Z. S._ 1882, p. 595 (Catamarca); _Barrows,
Bull. Nutt. Orn. Cl._ viii. p. 89 (Concepcion); _Sharpe, Cat. B._
x. p. 180. +Cotyle tapera+, _Burm. La-Plata Reise_, ii. p. 477.
_Description._--Entire upper parts dull brown; tail-feathers
blackish brown; throat ashy white; fore neck and chest ashy brown
in the centre and dark brown on the sides, as are also the flanks;
abdomen white; bill and feet horn-colour: total length 7 inches,
wing 5·5, tail 2·6. _Female_ similar.
_Hab._ Brazil, Paraguay, Argentina.
The Tree-Martin is more slender and has a greater extent of wing than
the Purple Martins; and, instead of the beautiful dark purple (their
prevailing colour), its entire upper plumage is dusky brown, the under
surface white. But if these differences of structure and hue merely
serve to show that it is not a very near relative of the other species,
those exhibited in its habits remove it very far indeed from them.
The Tree-Martin is a very garrulous bird, and no sooner arrives early in
September, than we are apprised of the circumstance by the notes which
the male and female incessantly sing in concert, fluttering and waving
their wings the while, and seeming quite beside themselves with joy at
their safe arrival; for invariably they arrive already mated. Their
language is more varied, the intonation bolder and freer than that of
our other Swallows. The length of the notes can be varied at pleasure;
some are almost harsh, others silvery or liquid, as of trickling drops
of water; they all have a glad sound; and many have that peculiar
character of some bird-notes of shaping themselves into words.
This Martin is never seen to alight on the ground or on the roofs of
houses, but solely on trees; and when engaged in collecting materials
for its nest, it sweeps down and snatches up a feather or straw without
touching the surface. It breeds only in the clay-ovens of the Oven-bird
(_Furnarius rufus_). I, at least, have never seen them breed in any
other situation after observing them for a great many summers. An
extraordinary habit! for, many as are the species that possess the
parasitical tendency of breeding in other birds' nests, none of them
confine themselves to the nest of a single species excepting the bird
I am describing. It must, however, be understood that my knowledge of
this bird has been acquired in Buenos Ayres, where I have observed it;
and as this Martin possesses a wider range in South America than the
Oven-birds, it is more than probable that in other districts it builds
in different situations.
On arriving in spring each pair takes up its position on some tree,
and usually on a particular branch; a dead branch extending beyond the
foliage is a favourite perch. Here they spend much of their time, never
appearing to remain long absent from it, and often, when singing their
notes together, fluttering about it with a tremulous uncertain flight,
like that of a hovering butterfly. About three weeks after first
arriving they begin to make advances towards the Oven-bird's nest that
stands on the nearest post or tree; and if it be still occupied by the
rightful owners, after much time has been spent in sporting about and
reconnoitring it, a feud begins which is often exceedingly violent and
protracted for many days.
In seasons favourable to them the Oven-birds build in autumn and winter,
and breed early in spring; so that their broods are out of their
clay-houses by the end of October or earlier; when this happens, the
Swallow that breeds in November quietly takes possession of the forsaken
fortress. But accidents will happen, even to the wonderful fabric of
the Oven-bird. It is sometimes destroyed and must be rebuilt; or its
completion has perhaps been retarded for months by drought, or by the
poor condition of the birds in severe weather; or the first brood has
perhaps perished, destroyed by an opossum or other enemy. November, and
even December, may thus arrive before some pairs have hatched their
eggs; and it is these unfortunate late breeders that suffer from the
violence of the marauding Swallows. I have often witnessed the wars of
these birds with the deepest interest; and in many ovens that I have
opened I have found the eggs of the Oven-birds buried under the nests
of the Swallows. After the Swallows have taken up a position near
the coveted oven, they occasionally fly towards and hover about it,
returning again to their stand. By-and-by, instead of returning as at
first, they take to alighting at the entrance of the coveted home; this
is a sort of declaration of war, and marks the beginning of hostilities.
The Oven-birds, full of alarm and anger, rush upon and repel them as
often as they approach; they retire before this furious onset, but not
discomfited, and only warbling out their gay seemingly derisive notes in
answer to the outrageous indignant screams of their enemies. Soon they
return; the scene is repeated; and this desultory skirmishing is often
continued for many days.
But at length the lawless invaders, grown bolder, and familiar with his
strength and resources, will no longer fly from the master of the house;
desperate struggles now frequently take place at the entrance, the birds
again and again dropping to the ground clutched fiercely together, and
again hurrying up only to resume the combat. Victory at last declares
itself for the aggressors, and they busy themselves carrying in
materials for their nest, screaming their jubilant notes all the time
as if in token of triumph. The brave and industrious Oven-birds,
dispossessed of their home, retire to spend their childless summer
together, for the male and female never separate; and when the autumn
rains have supplied them with wet clay, and the sense of defeat is worn
off, they cheerfully begin their building-operations afresh.
This is not, however, the invariable result of the conflict. To the
superior swiftness of the Martin the Oven-bird opposes greater strength,
and, it might be added, a greater degree of zeal and fury than can
animate its adversary. The contest is thus nearly an equal one; and the
Oven-bird, particularly when its young are already hatched, is often
able to maintain its own. But the Martins never suffer defeat; for, when
unable to take the citadel by storm, they fall back on their dribbling
system of warfare, which they keep up till the young birds leave the
nest, when they take possession before it has grown cold.
The Martin makes its own nest chiefly of large feathers, and lays four
eggs, long, pointed, and pure white.
It will be remarked that in all its habits above mentioned this bird
differs widely from the two preceding species. It also differs greatly
from them in its manner of flight. The Purple Martins move with
surprising grace and celerity, the wings extended to their utmost; they
also love to sail in circles high up in the air, or about the summits of
tall trees, and particularly during a high wind. At such times several
individuals are usually seen together, and all seem striving to outvie
each other in the beauty of their evolutions.
The Tree-Martin is never seen to soar about in circles; and though when
hawking after flies and moths it sweeps the surface of the grass with
amazing swiftness, at other times it has a flight strangely slow and of
a fashion peculiar to itself: the long wings are depressed as much as
those of a Wild Duck when dropping on to the water, and are constantly
agitated with tremulous flutterings, short and rapid as those of a
butterfly.
Neither is this bird gregarious like all its congeners, though
occasionally an individual associates for a while with Swallows of
another species; but this only when they are resting on fences or trees,
for as soon as they take flight it leaves them. Once or twice, when for
some mysterious cause the autumnal migration has been delayed long past
its usual time, I have seen them unite in small flocks; but this is very
rare. As a rule they have no meetings preparatory to migration, but
skim about the fields and open plains in un-Swallow-like solitude, and
suddenly disappear without having warned us of their intended
departure.