The European egg is smaller than the American, is often, but not always, more spherical, and is less pointed at the smaller end. Among its varieties is one which is quite common, and is very different from any I have ever observed among at least five hundred specimens of the American which I have examined.
An Osprey’s egg in my collection, taken near Aarhuus, in Denmark, by Rev. H. B. Tristram, of Castle Eden, England, measures only 2.12 inches in length,—shorter by a fourth of an inch than the smallest American,—in breadth 1.62 inches; its ground-color is a rich cream, with a slight tinge of claret, and it is marked over its whole surface with large blotches of a beautifully deep shade of chocolate.
In their habits the European and the American birds seem to present other decided differences. The American is a very social bird, often living in large communities during the breeding-season. The European is found almost invariably in solitary pairs, and frequents fresh water almost exclusively. The American, though found also on large rivers and lakes, is much the most abundant on the sea-shore. The European bird rarely builds on trees, the American almost always. The latter rarely resorts to rocky cliffs to breed, the European almost uniformly do so. There is no instance on record of the American species attacking smaller birds or inferior land animals with intent to feed on them. The European species is said to prey on Ducks and other wild-fowl.
Genus NAUCLERUS, Vigors.
- Nauclerus, Vig. 1825. (Type, Falco furcatus, Linn.; F. forficatus, Linn.)
- Elanoides, Gray, 1848. (Same type.)
Gen. Char. Form swallow-like, the tail excessively lengthened and forked, and the wings extremely long. Bill rather small, and narrow; commissure faintly sinuated; upper outline of the lower mandible very convex, the depth of the mandible at the base being only about half that through the middle; gonys drooping terminally, nearly straight. Side of the head densely feathered close up to the eyelids. Nostril ovoid, obliquely vertical. Feet small, but robust; tarsus about equal to middle toe, covered with large, very irregular scales; toes with transverse scutellæ to their base; claws short, but strongly curved; grooved beneath, their edges sharp. Second or third quill longest; first shorter than, equal to, or longer than, the fourth; two outer primaries with inner webs sinuated. Tail with the outer pair of feathers more than twice as long as the middle pair.
The genus contains but a single species, the N. forficatus, which is peculiarly American, belonging to the tropical and subtropical portions on both sides of the equator. The species is noted for the elegance of its form and the beauty of its plumage, as well as for the unsurpassed easy gracefulness of its flight. It has no near relatives in the Old World, though the widely distributed genus Milvus represents it in some respects, while the singular genus Chelictinia, of Africa, resembles it more closely, but is much more intimately related to Ictinia and Elanus.
52994, ♂. ½
