The Courtship of Animals

by W. P. Pycraft

[Face page 156.

Plate 28.

SKULL OF THE AMERICAN WHITE BEAKED PELICAN.

The beak of this bird develops at each breeding season an irregular horny plate which falls off at the end of this period, It is difficult to regard this as a sexual “ornament,” yet it comes under this category.

Photos copyright, G. Herring.

HEAD OF A PUFFIN, SHOWING THE MOULTING OF THE BEAK SHEATH.

At the breeding season, in both sexes, a triangular horny plate is developed over the eye, an oblong plate below it, while the sides of the beak become deepened by means of larger triangular horny plates. All these embellishments are highly coloured, and they are shed at the end of the breeding season. A further ornament is developed at the gape, in the shape of a fleshy rosette of a bright orange colour.