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Show 100 ~EXUAL SELECTION : UIRD. ·. direct and indirect cviclence. It is much more difficult to decide what qualities determine the c.hoice of t.he females; but here again we have some duect and mdirect evidence that it is to a large extent the external attractions of thGl male, though no doubt his vigour,. courao-e ancl other mental qualities come into play. 0 ' Vl c will begin with the indirect eviclence. Length of Oourtship.-The lengthened period during which both sexes of certain birds meet day after day at an appointed place, probably depends partly on the court hip being a prolonged affair, and partly on thereiteration of the act of pairing. Thus in Germany and Scandinavia the balzens or leks of the Black-cocks, last from the middle of March, all through April into J\1ay. As many as forty or :fifty, or even more birds congregate at the leks ; and the same place is often frequented durino- successive years. The lek of the Capercailzie lasts fr~m 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 ancl Eastern Siberia 1 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 arc well acquainted with the clea~·ed arenas, where they expect to :find the beautiful Cocks of the Rock· and the natives of New Guinea know the trees wher~ from ten to twenty full-plumaged male Birds of 1 Nordmann describes(' Hull. 'oc. Imp. des Nat. Moscow,' 18Gl, tom. xxxiv. p. 264) tho bulzcn of 'l~~t1·ao uroualloides in Amur Land. He estimated the numbl?r of nsscmblcu mrdcs at above t< l1tmdrcu, tln· females, which lie hid in the surrounding busll s, not 1Jeing counted. The noiscs uttered difl'cr from tlwse of the '1~ ~trooullus or the capcr-c! lilzie. C~<AP . Xl\'. LENGTH OF COURTSHIP. 101 :~radisc congregate. In this latter case it is not exP1 essl Y stated that tho females meet on tho same tree. but the huntorR, if not specially asked, would not pr;~ bably mention tl~oir presence, as their skins are valueloss. Small partJOs of an African weaver (Ploceus) c - gregate, ~uring the breeding-season, and perform ~:r hou_rs then· _graceful evolutions. Large numbers of th Sohta.ry smpe (Scolopax rnajor) assemble durino· th~ -dusk m a morass; and .the same place is frequent~cl for the same purpos~ durmg successive years; here they rna!. be seen l'lm.mn? about "like so many large rats," pufh~g out their feathers, flapping their wings and uttermg the strangest cries. 2 ' S~mc of the a~ov.e-mentioncd birds, namely, the bla~k-cock,. capercmlzie, pheasant-grouse, the ruff, the Sol~tary smpe, an~ perhaps some others, are, as it is behoved, polygamists. With such birds it mio-ht ha been th_ought that the stronger males would sim ~e th a1v- e dnven .a way the weaker ' and then at on ee hapv ye . a '"en. po~sesswn of as many females as possible. b t 'f 1t be mel Ispensa bl e l.[O! r t h e male to excite or ple,a seu th1e female, we can understand the length of the courtshi and the congregation of so many individuals of bot~ se~es at .the same spot. Certain species which are s::ICtly monogamous likewise hold nuptial assemblao·es. t IS seems. to be the case in Scandinavia with on~ ol' the ptarmigans, and their leks last from the middle o~ March to the middle of .1\fay. In Australia the lyrebud or Menura superba forms ,, small round hillocks ,, ' : With respect to the nssemblno- f tl b Brehm, ''l'hicrlebcn , 13 . ,' ! - ,..,~s o IC n ove nnmcd gl·ouse sec Sweden' 1867 ' . 11 •• s. 3o0' nlso L. Lloyd, , Game l3il-cls of P 3G'> ' I' f ' p. lD, _78. Rtehnnlson, 'l•'auna 13or. Amerir:ma, Bird' · -· "c erenccs m rco-nrd t tl • · • l>rcviously be · . 0 ° ~ 10 assemblages of other birds have .,r Nat. llist/~or:~n.l85; Pnrnc;~sen sec 'Vnlln_cc, in' Annols nnd l\ing. · · , P· 1L. On tho sn1pe, Lloytl, ibid. p. 221. |