Fig. 84.–Hoopoe. Upupa epops. × ¼. (From Natural History of Selborne.)
Upupa epops not unfrequently visits Britain, where it has nested on several occasions; it breeds from Southern Scandinavia to Northern Africa and the Atlantic Islands, migrating a little further south; while it extends through most of Asia and reaches Japan. The fine erectile crest, the head, neck, and lower parts are cinnamon-coloured; the remaining plumage is black, varied with buff and white; a band of the latter crosses the tail; and the head plumes are tipped with black and white. U. marginata of Madagascar has a larger outer primary and a narrower tail-band; U. indica, with darker cinnamon tints, extends from India to Hainan, and intergrades with U. epops; U. somalensis of Somali-Land is intermediate between the last and U. africana of South Africa, which exhibits no white on the primaries or crest. Females and young are duller and less crested.
A fossil form, Limnatornis, occurs in the Lower French Miocene.
Sub-fam. 2. Irrisorinae.–The Wood-Hoopoes, differing from their allies in the longer and more decurved bill, especially noticeable in Rhinopomastus, the long wedge-shaped tail, and the absence of a crest, are commonly seen in flocks of from six to eight; they are shy, restless and noisy, flitting from bush to bush with undulating motion and expanded rectrices, while they also creep about probing the crannies of the highest trees–to the great detriment of the tail–or search the ground for grubs and insects generally. The note is harsh and chattering; the nest, said to be foul like that of their allies, is placed in holes in trees, the eggs being apparently white. The plumage is metallic purple, blue or greenish, with white wing-patch and tail-markings, the females and young being less bright, with shorter beaks.
Irrisor occupies the Ethiopian Region, I. viridis and I. erythrorhynchus having the head and throat bluish-green, I. bollii those parts buff, I. jacksoni nearly white. Three species of Scoptelus inhabit North-East and West Africa, three of Rhinopomastus extend from the former country and the Congo to South Africa.
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The Sub-Order Striges, containing the natural and well-marked group of the Owls, was until lately usually treated as a mere Family situated next to the diurnal Birds of Prey (Accipitres of this work), whatever name or rank may have been given to the combined assemblage. Gradually, however, a conviction has arisen that these nocturnal–or chiefly nocturnal–Birds of Prey deserve a higher position than that of a Family, while Dr. Gadow, in the classification here mainly adopted, agrees with those who would separate them widely from their former associates, and places them in close proximity to the Nightjar alliance (Caprimulgi), the members of which they certainly resemble in their soft plumage, large eyes, and crepuscular tendencies.
Fam. VII. Strigidae.–This, which contains all the Owls, may be divided into two Sub-families, (1) Striginae and (2) Buboninae.[[230]] In the former, or Screech-Owl section,[[231]] the sternum has its broad keel joined to the furcula, and exhibits no notches behind; in the latter, containing the remaining genera, the clavicles do not always form a furcula, nor do they meet the sternum, which shews one or two pairs of projections posteriorly. In this section, moreover, there is a bony loop bridging the channel in the metatarsus which contains the common extensor tendon of the toes, as is the case in the Osprey. Pterylography would lead to the same subdivisions. Between the two groups lie Photodilus of the Indian Region, now referred to the Buboninae, and Heliodilus of Madagascar, which is classed with the Striginae.
The head is large; the neck short and thin; the bill moderate in length, but stout, with a sharp hook at the tip; the culmen is usually curved, but is straighter in Strix, while the basal cere is more or less covered by feathering, especially in Nyctea. The short, strong metatarsi–somewhat longer in Speotyto and Sceloglaux–are flattened in front and covered with small scales. They are usually feathered, though in Ketupa and Scotopelia they are all but bare, while they are partly so in Scops gymnopus and S. nudipes, the two former having the toes provided with spicules below, as in Pandion. Many forms have the plumage extended as a thick covering of soft feathers or bristles to the claws, which are normally long, sharp, and curved, that of the middle toe having a serrated margin in the Striginae. The digits are padded beneath, and the fourth of them is reversible at will, enabling Owls to perch with either one or two toes behind. The wings are long, or fairly so, very broad, and more or less rounded, Scops and Strix being instances of greater length, Bubo, Sceloglaux, Speotyto, and Photodilus of shortness; the primaries number eleven and the secondaries from eleven to eighteen. The tail of twelve rectrices is generally short and somewhat rounded, though longer in Surnia. The large eyes are directed obliquely forwards, but those of Ninox are said to have a less staring look; Owls, moreover, have little power of turning the eye-ball, and consequently add to their grotesque appearance by constantly moving the head from side to side. The upper eye-lid shuts over the eye, and not the lower, as in birds generally; the iris is extremely sensitive, contracting and expanding continually. The external ear varies in an extraordinary way, the "conch," or large shell-like aperture, often having its ample membranous margin developed into an elevated operculum or flap which stretches partially or entirely down the anterior side. In Asio and Syrnium the ear-openings are asymmetrical, those of the former reaching nearly the whole height of the skull and being directed respectively upwards and downwards; in Nyctala this asymmetry extends to the bones of the skull itself. The large ear is apparently correlated with a keen sense of hearing in some cases, but not in all.
The furcula, when complete, is U-shaped; the tongue is fleshy, and somewhat horny below; the nostrils, placed towards the front of the cere, are rather large, and usually concealed by bristles; the syrinx is bronchial; the after-shaft is absent or rudimentary; down occurs in the adults only on the unfeathered spaces, but in the nestlings forms a woolly coating, which may be brown or dusky, as in the Snowy Owl, white as in the Screech-Owl, yellowish or grey, as in many species.