Geoscience Reference
In-Depth Information
A
B
Figure 7-29.
A. Lesser snow goose (
Anser
caerulescens
) displays the “blue goose” plumage. B.
White-fronted goose (
A. albifrons
). Both these species
are slightly smaller than domestic geese. They spend
summers in the Arctic and head to California and Texas
for winters. Photos by J.S. Aber.
Figure 7-31.
The black swan (
Cygnus atratus
) is native
to Australia and Tasmania, but has been widely exported
and bred for pets and zoos. Photo by J.S. Aber.
(Fig. 7-32). Their i shing techniques vary consid-
erably. The anhinga (
Anhinga anhinga
) swims
with only its head and neck above water, which
gives rise to its nickname, snakebird. Like the
great blue heron, it spears i sh with its long,
sharp beak. Returning to its nest, it tosses the
i sh into the air and swallows it head i rst
(Niering 1985). Unlike most aquatic birds,
however, its feathers are not waterproof, so it
must spend considerable time drying in the sun
(Fig. 7-33).
The American white pelican (Fig. 7-34) uses
its extremely large bill like a dip net to scoop
i sh out of the water. Pelicans often practice
group hunting, in which they form long lines
and beat their wings to drive i sh into a circle
or toward a shallow shore where they capture
Figure 7-30.
Small Canada goose (
Branta canadensis
)
displays its characteristic black-and-white neck while
resting on a grassy lawn. Photo by J.S. Aber.
