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

BIRDS OP ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 117
beating wings into the trees, or if found on high perches flew with
a few quick strokes of the wings that terminated in a short sail
in a direct line with long tail slightly spread and neck outstretched.
They alighted as easily as jays, ran quickly along the large limbs
and were lost at once to view. In the tops of trees they remained
motionless to escape observation, but were often betrayed by the
outline of the long tail or by a moving shadow caused by a head
concealed behind leaves. When flocks chanced to alight overhead
without having seen me approach the birds examined me curiously
as they uttered low whining calls. When at ease they sank on the
breast like pheasants and turned the head quietly from side to side.
When excited the long neck was extended to full length. Flocks
came to feed in flowering lapacho trees standing at the border of the
forest, apparently in search of the blossoms.
The mating season, heralded by the harsh calls of the males, began
in September. Near at hand I found that the call began with a low
resonant note followed by a harsh cackle that changed in tone and
continued in rapid repetition for nearly a minute, thus, &m/?, ka
chee chaw raia taw, chaw raiu taw, chaw raw taio, a call that carried
easily for half a mile. At once this was answered by another bird,
another and another until perhaps half a dozen were calling from
near at hand. At this season they were heard many times at night.
On warm spring mornings the notes were heard on all sides—an
odd chorus, barbarous and uncouth, but attractive in spite ot its
harshness. When engaged in calling males sought a commanding
perch often in the top of some tall tree and were so engrossed in
their challenges that it was possible to stalk them without great
care. At times they were accompanied by females; copulation took
place in the tree tops.
One morning I secured a bird just as a heavy rain came on. On
skinning it later I found the cavity of the large oil gland entirely
empty and judged that it had used the supply of oil to prepare for
the coming storm.
The ancient Guarani name of Yacii-Caraguata given to this bird
in Azara's time has been abbreviated to Yacii though the species
is called more frequently by the term Charata. The Tobas in Formosa
knew it as Gua che na (a cog-nomen of evident onomatopoeic
origin) and the Anguetes in Paraguay as Kin a tee.
The trachea in females of this species is normal. In males it is
elongated to form a loop over the breast muscles on the right-hand
side that reaches to the keel of the sternum and then turns to pass
back and enter the thoracic cavity. From the lower end of the loop
a slender band of muscle passes back to insert on the connective
tissue overlying the pectoralis major above the end of the keel on