CHAPTER XL 



The Owls and Ospreys, — Orders Striges and Pandiones. 



The well-known and peculiar physiognomy characterising most of the owls renders 

 the group as readily distinguishable as that of the parrots. This characteristic 

 " owl-face " is due, firstly, to the forward direction of the eyes ; and, secondly, to a 

 circular disc of radiating feathers, more or less distinctly developed round each eye, 

 and which may be bounded by a ruff of closely-set feathers. In common with many 

 diurnal birds of prey, the owls have a short, stout beak, of 

 which the upper ridge is strongly curved, and the tip deflected 

 in a perpendicular direction; at its base is a cere, usually 

 covered with stiff bristles concealing the nostrils. The feet 

 are furnished with strong, curved, and sharp claws, and have 

 the fourth toe reversible. The metatarsus, or cannon-bone, 

 although longer than in the parrots, is comparatively short and 

 wide, with the upper part of its front surface deeply excavated, 

 and usually furnished with a bony bridge over the outer part 

 of the hollow ; at its lower end the three pulley-like trochlese, 

 when viewed from below, are arranged in an arch. In the 

 tibia, or leg-bone, there is no bony bridge at the lower end, as 

 in most parrots. The short skull has no well-marked hinge at 

 the root of the beak ; the palate is of the bridged, or desmo- 

 ^^Q^^ gnathous type ; and the lower mandible has a short and shallow 



W^W^^m symphysis, and its angle is not produced behind the surface 



W V for articulation with the quadrate bone. The oil-gland is pre- 



sent, but naked. 



The foregoing characters, especially those of the toes and 

 leg-bones, serve to distinguish the owls from the parrots on 

 the one hand, and the diurnal birds of prey on the other ; but the two are very 

 closely connected in these respects by the ospreys. In addition to the features 

 noticed, owls, as a rule, are characterised by the large size and dense feathering of 

 their heads, the softness and fluffiness of the whole plumage, and their big, round 

 eyes ; the feet being usually feathered down to the toes. The ears are usually of 

 large size, and are often protected by an operculum or lid ; from which we may 

 infer that the sense of hearing in these birds is highly developed. Many owls are 

 furnished with tufts or crests of feathers above the eyes, popularly known as horns 

 or ears, but more properly termed ear-tufts. The coloration is usually a mottled 

 blending of various sombre tints ; bright colours being, as might be expected in 



1 The bridge over the hollow at the upper end is imperfect. 



THE RIGHT CANNON-BONE, 

 OB METATARSUS, OF 

 THE SNOWY 0WL.1 



