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

BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 127
At Lavalle, Buenos Aires, limpkins were noted on November
2 and 9, and several were recorded on November 16 when crossing
to Santo Domingo. On February 2, 1921, I killed an adult male
(preserved as a skeleton) at the Paso Alamo on the Arroj'o Sarandi,
north of San Vincente, eastern Uruguay. In the marshes
bordering the Rio Cebollati near Lazcano, Uruguay, the birds were
fairly common from February 6 to 9, and at Rio Negro, Uruguay,
I found them from February 15 to 18.
In the Chaco limpkins ranged in open, rush-grown marshes, probably
because the season was winter and water holes and swamps
had become dry in wooded sections. Similar regions were inhabited
on the pampas as these formed the only tracts in this area suited
to the habits of this species. Elsewhere limpkins frequented wooded
swamps, areas that seemed better suited to their needs. In traversing
the open country the birds flushed frequently from small openings
among the rushes, rising with the peculiar flight that marks them
as far as they can be seen. When the bird is not hurried the wings
are extended at an angle of 45° above the back, and are stroked
quickly at short intervals down to the level of the body, but little
or no farther, and then raised again. At the highest point of
elevation there is a distinct pause before the wing is brought down
again, so that the bird sails for a few feet with stiffly held raised
wings. The whole wing motion suggests that of some huge but-
terfly save that the line of flight is direct rather than erratic.
When startled the birds flap away as any crane or stork might with
neck extended and legs trailed behind.
In dense wooded swamps my attention was frequently attracted to
limpkins by abrupt explosive or clattering notes that often resembled
the syllables koy kop or kawp. The ordinary call of car-r-r-rau carr-r-rau,
that gives this and the northern limpkin their common name
throughout their range in the West Indies and Latin America, may
be heard for a great distance. Two or three individuals calling at
once may cause a tremendous noise; in fact one might well believe
that the chorus was produced by a considerable congregation of birds
concealed in the bushes.
Limpkins often sought elevated perches in the tops of low trees or
rested concealed among heavier growth, where they turned the head
from side to side and at short intervals twitched the tail upward
with a quick jerk that suggested a similar motion common among
rails. Their food consisted mainly of large fresh-water snails
{Avipullaria insularum d'Orbigny). Empty shells of these mollusks
were found in abundance resting on the mud, with the opening
upward and the thin, corneous operculum lying a few inches away,
where it had dropped after it had been pulled away. At rest the
birds appear remarkably ibislike.