THE VALIDITY OF SOME GENERA OF LARKS (ALAUDIDAE)

The larks (Alaudidae) tend to be taxonomically arranged in a large number of small genera. There appear to be few characters which will separate the genera Alauda, Galerida and Lullula, and in recent times additional species have been placed in the first two genera without a reappraisal of the characters by which each genus is defined. Ten species are involved and originally these belonged to eight different genera. In this group of ten species of eight genera as at present, six morphological generic characters are examined separately: the length of the tenth primary in relation to the roundness of the wing, the length of the hind claw, the profile of the crest, the conspicuousness of the superciliary stripe, the thickness and taper of the bill, and the length of tertiaries and secondaries. All ten species show these characters, and the variation in any single character is fairly evenly graded through the group without marked discontinuity. The succession of species within the gradation varies from one character to another. It is not possible to find any group of characters which will subdivide the group of species. Little is known of the behaviour of the ten species but examination of song-flight suggests that such characters may also show a gradation without obvious subdivision. It is considered that the present data do not justify the retention of the present genera for these species, and that it would be preferable to group them under the earliest generic name, Alauda. The characters defining the Alauda group are listed and the relation of Chersophilus duponti to the group is discussed.