Page:The Zoologist, 4th series, vol 2 (1898).djvu/136

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Volume II. of 'British Birds with their Nests and Eggs' (p. 174), I have noted the fact that bird-dealers recognise cock Sky Larks, by the greater length of the second primary of the wing in that sex. I had intended to illustrate the well-defined sexual differences in this species by a process-block (l.c.), as I did in the case of the Linnet, but unhappily when the wings were needed Mr. Frohawk was utterly unable to obtain examples for illustration, whilst at that time I possessed the male wing only.

I now have before me eight wings, four of which (two right-hand wings of each sex) were secured, mounted, and kindly given to me by Mr. C.H.B. Grant, who shot these and other birds last December in Hampshire.

The wing of the male Sky Lark, as I have already stated elsewhere, is especially adapted for powerful and sustained flight, whereas that of the female is altogether weaker in construction; indeed, so greatly do the wings differ in old birds that a glance would enable the dullest observer to decide their sex; even in young birds the distinctions are well marked.

As is well known, the first primary in the Sky Lark (as in many Passerine birds) is very small; so that by a superficial observer it might easily be confounded with the coverts. The second, third and fourth primaries are, however, the longest in the wing, and in the male Sky Lark these three feathers terminate almost at the same level; thus when superposed there is hardly any noticeable difference, though the third primary is very slightly the longest. In the female the second primary is decidedly the shortest of the three and either the third or the fourth the longest, these three feathers in the female thus either forming an