by much direct and indirect evidence. It is far more difficult to
decide what qualities determine the choice of the females; but here
again we have some direct and indirect evidence that it is to a large
extent the external attractions of the male; though no doubt his
vigour, courage, and other mental qualities come into play. We will
begin with the indirect evidence.
LENGTH OF COURTSHIP.
The lengthened period during which both sexes of certain birds meet day
after day at an appointed place probably depends partly on the
courtship being a prolonged affair, and partly on reiteration in the
act of pairing. Thus in Germany and Scandinavia the balzen or leks of
the black-cocks last from the middle of March, all through April into
May. As many as forty or fifty, or even more birds congregate at the
leks; and the same place is often frequented during successive years.
The lek of the capercailzie lasts from the end of March to the middle
or even end of May. In North America the partridge dances of the
Tetrao phasianellus last for a month or more. Other kinds of grouse,
both in North America and Eastern Siberia (1. Nordman describes ( Bull.
Soc. Imp. des Nat. Moscou, 1861, tom. xxxiv. p. 264) the balzen of
Tetrao urogalloides in Amur Land. He estimated the number of birds
assembled at above a hundred, not counting the females, which lie hid
in the surrounding bushes. The noises uttered differ from those of T.
urogallus.), follow nearly the same habits. The fowlers discover the
hillocks where the ruffs congregate by the grass being trampled bare,
and this shews that the same spot is long frequented. The Indians of
Guiana are well acquainted with the cleared arenas, where they expect
to find the beautiful cocks of the Rock; and the natives of New Guinea
know the trees where from ten to twenty male birds of paradise in full
plumage congregate. In this latter case it is not expressly stated that
the females meet on the same trees, but the hunters, if not specially
asked, would probably not mention their presence, as their skins are
valueless. Small parties of an African weaver (Ploceus) congregate,
during the breeding-season, and perform for hours their graceful
evolutions. Large numbers of the Solitary snipe (Scolopax major)
assemble during dusk in a morass; and the same place is frequented for
the same purpose during successive years; here they may be seen running
about like so many large rats, puffing out their feathers, flapping
their wings, and uttering the strangest cries. (2. With respect to the
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