Abstract
Distributed worldwide are eight
species of swans, most of which are
found in the northern hemisphere.
Only two, the Black Swan of Australia
and the Black-necked Swan of South
America, are native to the southern
hemisphere. Exclusive of Antarctica,
Africa is the only continent to which
swans are not native.
The species with which most people
are familiar is the Mute Swan of
Europe. It is especially well known in
Britain where it has been maintained
in parks and estates for hundreds of
years. It is now considered a semidomesticated
species. It is this species
that is widely known from early literature,
fairy tales and mythology. It is
interesting that they should have been
named Mute Swans for, while they do
not have powerful voices, they are far
from mute. Their call is comparatively
soft -a rather melodious, mewing
call. Other northern swans have
powerful trumpeting calls so that by
contrast the Mute is much less vocal.
Perhaps this might explain the name.
All swans are ornamental, being
especially graceful upon water. This is
particularly true of the Mute. It carries
its wings in a raised, arched position
above the back, with the neck gracefully
curved -a handsome sight
indeed. They are at their best upon
water, where much of their time is
spent. Of all swans, the Mute's legs are
positioned further back on the body.
As a result, they are less adept upon
land where they walk with a somewhat
labored and rolling gait. Mutes
are one of the largest of the clan,
being equaled or surpassed only by
the Trumpeter of North America,
which, indeed, is the largest of the
world's waterfowl.
In
addition to their long history in
Europe, Mutes have been maintained
in American collections for many
years. They breed very well and
escaped birds have established themselves
in the wild. They have become
relatively abundant in eastern areas of
the United States where they pose
some significant problems. In addition
to being dominant over native American
species, their feeding habits are
destructive to the ecosystems of
shallow marshland areas.
The Black-necked Swan of South
America and the Black Swan of Australia
are the two representatives of
the southern hemisphere. Both are
highly ornamental, adjust well to captivity,
and are dependable breeders.
As the name applies, the Australian
swan is entirely black. However, there
is a strong silvery cast to the plumage
and the back feathers are curly. The
curled feathers are unique to the species
and give it a particularly pleasing
appearance. The eyes and bill are red,
which is also unique, as other swans
have black eyes and black is the predominant
bill color. In all swans, the
upper mandible extends all the way
through the lares area to the eye. The
Australian swan has an unusually long
neck, which it arches gracefully. It
also has the capability to fluff the neck
feathers in a particularly pleasing
manner. The voice is somewhat similar
to the Mute's -a soft whistling,
mewing call. As one might imagine, the Black-
necked Swan's head and full length of
the neck are black. The body is white
and the bill has red and blue coloration.
There is a sizable knob on the
upper mandible, It is the smallest of
the swans, is very attractive, and
comparatively scarce in avicultural
collections.
South America is the home of an
additional bird, the Coscoroba, which
has been included in the swan family.
It has been included with the swans
largely on the basis of its being a large
all white bird (the wing tips are black).
Actually the Coscoroba is much more
closely aligned with the whistling
ducks than the swans. The bill is much
different from that of the swans. The
eye is pale and the legs are long and
well forward, features typical of whis-
tling ducks. Especially significant is
the strongly mottled pattern of the
downy young which, again, is similar
to downy whistling ducks. Downy
young of true swans are all silvery
gray with no pattern. The Coscoroba
is a form unique unto itself but should
not be included with the true swans.
In addition to the Mute Swan, there
are five species native to the northern
hemisphere. These are the Tmmpeter
and Whistling Swans of North America,
and the Whooper, Bewick and
Jankowski swans of Eurasia. Collectively,
these five are kno~n as the
northern swans, and all are similar in
appearance and habits. All are pure
white with black feet and bills. Again
-the upper mandible extends
through the !ores area to the eye, and,
exclusive of the Trumpeter, in which
the !ores area is black, a bright yellow
lares patch is characteristic.
The extent of the yellow patch varies
according to species. It is smallest
in the Whistler or Tundra Swan and
largest is the Whooper. In the latter
form, the yellow extends all the way
from the eyelids to well forward of the
nostrils so that only about the fo1ward
third of the mandible is black.
The Bewick (which incidentally is
pronounced "buick") and the Jankowski
have a comparatively smaller
area of yellow than has the Whooper,
but decidedly greater than that of the
Tundra Swan. The differences between
the Bewick and Jankowski are
so slight that taxonomists now believe
they may be a cline of a single species.
The name Bewick should prevail.