Canada Geese are not so aquatic in habit as are ducks. Large flocks often descend to the fields where they feed upon grass or sprouting grain and where they walk about in a dignified fashion.
It is supposed that an old gander always leads the migration flocks. While this may not be the case, it is reasonable to assume that adult birds, with their experience and intelligence, should determine the movements of the flock. Canada Geese sometimes fly in a line, sometimes abreast, but the V-formation is characteristic.
The Greater Snow Goose (Chen hyperboreus nivalis), a white bird with black wing-tips, sometimes flies across Pennsylvania. It has been recorded once or twice in huge flocks. The White-fronted Goose (Aner albifrons gambelli), a gray goose with a white area at the base of the bill, black spots on the belly, and yellow feet, occurs rarely. The Brant (Branta bernicla glaucogastra), smallest of our geese and similar to the Canada Goose but with only a suggestion of a white band on the neck, occurs rarely. It is a maritime species, not often noted inland.
WHISTLING SWAN
Cygnus columbianus (Ord)
Description.—Size very large; neck extremely long, and wing-spread sometimes as much as 6 to 7 feet; sexes similar. Adults: Pure white; bill and feet black, a small yellow spot at base of upper mandible just in front of eye; eyes brown. Young birds are pale brownish gray in color, usually darkest on the head and neck. As the immature plumage is replaced by the adult plumage, a vague mottling appears. Length: About 4½ feet.
Range in Pennsylvania.—A fairly regular migrant along the larger waterways; rare and irregular elsewhere; occasional in winter. It is usually seen in early spring from March 20 to April 15 and from October 15 to December 1.
A flock of swans flying in the sunlight is an inspiring spectacle. The birds are so large and their plumage so immaculate that they attract attention everywhere.
They sometimes migrate in immense flocks. In storms or on foggy nights they may become bewildered and descend to smaller streams, but, as a rule, they are found only along large open stretches of water.
At Harrisburg, swans sometimes spend the winter along the Susquehanna when the water is open.
The Trumpeter Swan (Olor buccinator), always a very rare bird in the eastern United States, and of late thought to be on the verge of extermination, is even larger than the Whistling Swan. The bill of this species is entirely black, lacking the yellow spot which is characteristic of the adult Whistling Swan and being of a different shape.