ANATOMY OF BIRDS
GEOGRAPHICAL DISTRIBUTION
MIGRATIONS OF BIRDS
CLASSIFICATION OF BIRDS
LIZARD-TAILED BIRD
AMERICAN TOOTHED-BIRDS
THE OSTRICHES
THE RHEAS
EMEUS AND CASSOWARIES
THE TINAMOUS
THE KIWIS
THE PENGUINS
LOONS AND GREBES
ALBATROSSES & PETRELS
STORK-LIKE BIRDS
GOOSE-LIKE BIRDS
FALCON-LIKE BIRDS
FOWL-LIKE BIRDS
CRANE-LIKE BIRDS
PLOVER-LIKE BIRDS
CUCKOO-LIKE BIRDS
THE ROLLER-LIKE BIRDS
SPARROW-LIKE BIRDS
Birds and Birding's Guide to:
Watching THE ROLLER-LIKE BIRDS
THE ROLLERS AND THEIR ALLIES
THE OWLS
(Suborder Striges)
The Owls were formerly, and indeed by some authorities are still, regarded as being most closely related to the diurnal birds of prey, or to the Hawks and Eagles (Accipitres), the two, it is assumed, constituting groups of coordinate rank, but the conviction has been growing of late years that the Owls are entitled to a higher rank and that their relationship is rather with certain”Picarian”groups, especially with the Goatsuckers. Beyond the fact of their raptorial habits and the shape of their bills and feet, which have largely resulted from these habits, there is really very little to be said regarding the kinship between the Owls and the Hawks and Eagles, and it is held that they could not have been derived from a common stock.
For instance, the ambiens muscle, which is regarded as of high taxonomic importance, is present in all Accipitres and absent in all Owls, and Gadow, whom we are largely following, urges the impossibility of the Owls once possessing and subsequently losing this muscle. Other anatomical differences are the basipterygoid processes, present in all Owls and absent in all Accipitres except in the American Vultures and the Secretary-Bird, which resemble the Owls least of all members of that group; the caeca, well developed in the Owls and rudimentary in the Accipitres; the oil-gland, nude or practically so in Owls and tufted in the Hawks and Eagles; and finally the aftershaft, which is present in all Accipitres except the Ospreys, and absent in Owls, except a very minute one in certain Barn Owls. In these characters, however, they agree with the Coraciiformes and are here regarded as a suborder of that group, and placed next the Goatsuckers (Caprimulgi), all, it is assumed, having arisen from a common ancestral stock.
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