AMERICAN MERGANSER. Mergus americanus Cassin

Field characters.—Size large for a duck; head, neck, and bill slender; large patch on wing, and whole lower surface of body, pure white. Male: head greenish black; middle of back black. Female: head reddish brown; back grayish brown.

Occurrence.—Casual visitant. Flock of six seen on Merced River about Merced Falls, January 2, 1915.

The American Merganser, is the only species of 'fish duck' we saw in the Yosemite section. Either this species or its relative, the Red-breasted Merganser, is likely to visit any fish-inhabited pond or sluggish stream during the winter months. The American Merganser is known to nest farther north in the Sierra Nevada, but the conditions afforded in the Yosemite region do not seem to attract the birds to remain here during the summer months.