Notes on Sexual Selection.



213



the duil ducks above mentioned, which display in the

same attitudes as the brightly-coloured Mallard drake.


III. The display is often provoked by other emotions than


amatory passion, e.g. anger; anyone can see this in the

case of the Turkey and Muscovy duck, both of them

irritable as well as amorous birds, and I have observed

it in many species; the common Moorhen ( Gallinula

chloropus) shows it very well.


IV. The female, both in plain and decorated species, displays


as well as the male in many cases, and generally in the

same attitude, e.g. the Peahen may be seen to show off

to the Peacock with erect and expanded tail ; I have

seen her do this both when the cock was displaying and

when he was not (different pairs in each case). Similarly

females as well as males may fight for the favours of the

opposite sex, as Mr. D. Dewar has seen with the Paradise

Flycatcher ( Terpsiphone paradisi).


V. Young male birds [e.g. young Peacocks and Gold Pheasants)

display before they are decorated, and birds which change

their plumage may do it when out of colour (Jackson’s

Whydali ( Drepanoplectes jacksoni) and Blue Wren

(.Malurus cyaneus).


VI. The display generally brings out the birds’ best points,


i.e. emphasizes the masculine characteristics or what

decorations the species may possess if both sexes are

decorated. This is well seen in the courtship of the

Sparrow and in the erection of the long head- and back

plumes in Herons.


VII. Display generally leads to fighting as well, as in the tour¬


naments of Ruffs (. Pavoncella pugnax) and Blackgame

(Tetrao tetrix) ; but some very ostentatious birds rarely

fight, though they drive each other about and show much

courage in encounters with other species, e.g. Peafowl

and Mandarin ducks (Aex galericulata ) ; while some do

not even meet each other when displaying; like the

Argus Pheasant ( Argusianus argils') and so cannot fight,

though fierce enough.


VIII. Males may assemble and display without any females



