Man-o'-war Birds or "Frigates," as they are often called, are remarkable birds in many respects. In comparison with their weight they have the largest expanse of wing of any known bird. Weighing only about four pounds they have an extent of from seven to eight feet, their wings being extremely long and pointed. The length of the bird is about 40 inches, of which the tail comprises about 18 in., 10 inches of this being forked. They have a large bright orange gular sac, a long, hooked bill, and small slightly webbed feet. Their powers of flight combine the strength of the Albatrosses and the grace of the Terns. They are very poor swimmers and do not dive, so are forced to procure their food by preying upon the Gulls and Cormorants, forcing them to drop their fish, which the pirates catch before it reaches the water. They also feed upon flying fish, catching them in the air, whither they have been driven by their enemies in their natural element. They nest in large colonies on some of the Bahama Islands and on some of the small Florida Keys. Their nests are small frail platforms of sticks and twigs and the single egg is laid in March and April. It is white and has a smooth surface. Size 2.80 × 1.90. Data.--Key Verde, Bahamas, March 6, 1889. Single egg. Nest a frail affair of sticks on a cactus. Collector, D. P. Ingraham. [Illustration 088: White.] [Illustration: Man-O'-War Bird.] [Illustration: deco.] [Illustration: left hand margin.] Page 87 Order V. ANSERES DUCKS, GEESE AND SWANS. Family ANATIDAE The birds comprising this family are of greatly varying sizes, but all have webbed feet, and generally the bill is broader than high, and is serrated on the edges or provided with gutters to act as a strainer in assisting the birds to gather their food. 129. MERGANSER. _Mergus americanus._ Range.--North America, breeding from the northern border of the United States northward. The three species of Mergansers are almost exclusively fish eating birds. Therefore their flesh is unpalatable and they are known as "Fish Ducks." They are also sometimes called "Sawbills" because of the teeth-like serration on both the upper and the under mandibles. Unlike the other species of ducks, their bills are long, slender and rounded instead of being broad and flat; it is also hooked at the tip. Like the Cormorants, they often pursue and catch fish under the water, their teeth-like bills enabling them to firmly hold their prey.