Page:Bird-lore Vol 04.djvu/205

 184 Bird - Lore

birds are found in the United States, and most of them. as indicated above, come from southern latitudes, one of the largest and ﬁnest being the Chilean Plover (Belunoptrrm (bi/ends). The spur is situated just at the base of the thumb and, like the spurs on the legs of other birds, Consists of a sheath of horn ﬁtting closely over a core of bone (Fig. 2). Some of the spur-winged Plov- ers have ﬂeshy wattles about the face, whence the names Labia/ant!!!” (Fig. 3), lobed» plover. and Sarriupbarm. ﬂeshebearer; and there is a curious relation between the size of the spur and the size of the wattle. for when one is large the other is correspondingly well developed. and when the wattle is small the spur also is small. No such relation as this exists between the spurs and wattles of domesticated iowls, but in their case selection has been artiﬁcial and not natural. so the instances are not similar.

The pretty little Jacanas are among the spur~winged birds. and it is ap- parent from the length and slendcrness of the toes that spurs upon the legs would be of little or no use for the birds would probably not be a success as kickersi Now there is a group of Jacanas peculiar to Africa which have no spurs on their wings. and these present a curious modification of the radius. or outer bone of the forearm (Fig. 4). so that this may serve instead. The bone is ﬂattened and widened until it somewhat resembles an Australian throwingvstick in miniature and pro-

Fic. ;. anm at the African lacana

he, 5. Pan u! m- winz 0! the Svnrrwinzcd Gnosr

jects so far beyond the edge of the wing that it makes a very effective little‘

weapon with which to buffet an adversary about the ears. There seems to be, however. one disadvantage about this arrangement; that is, the blow ought to hurt the bird by which is delivered about as much as the one by which it is received. but it birds are like unieathered bipeds there would be much consolation in knowing that the more one smarts the worse is the opponent punished.

The Spurrwinged Goose. Plutraplerur gambemix, shows a variation in the making of a weapon by having the spur on one of the wrist bones instead of on the metacarpus (Fig. 5), where it is usually placed, but this only serves to show that nature is not bound to any hard and fast

Ho. I»

The double sxvur 0! [hr 5mm."

method of equipment.