122 THE BIRDS OF BRITISH GUIANA. 
known, had not before been recorded as resident in the 
locality. 
Of our peculiar families, I need only mention such as the 
Sugar-Creepers, the Greenlets, the Mannikins, the Cotingas, 
the Trogons, the Toucans, the Barbets, the Hoatzin, the Tina- 
mous, the Curassows, and other equally restricted tropical 
American forms; while others, such as the Tanagers, the 
Tree-Creepers, the Ant-Thrushes, the Tyrant-Shrikes, the 
Humming-birds, the Hang-nests and other such forms, which, 
though they range into the temperate parts, yet are enor- 
mously abundant in the tropics, will occur at once to your 
minds. It is worth noting in this connection that many of 
those families, such as the Crows, Starlings, true Shrikes, and 
true Creepers, which give so many characteristic types to 
the Northern regions and to the Old World, are almost, if 
not entirely, absent from the American tropics. 
A noteworthy characteristic of our birds also is the very 
marked abundance of the individuals of a species. This no 
doubt is due to the protection afforded them by the abun- 
dance of trees in the forests and bushy plains, and to the 
enormous quantity of food in the form of seeds, fruits and 
insects, with rapid multiplication in an almost uniform and 
favoring temperature. Very many forms are only to be 
met with in well-defined districts ; thus, the species of such 
genera as Cotinga, Xipholena, Phenicocercus, Gymnocephalus, 
Gymnoderus, are only encountered in densely forested 
localities; Auficola only in the hills; Fluvicola, Pitangus, 
Arundinicola, Quiscalus only in open places and along the 
river sides; while others, such as Zroglodytes and Cassicus, 
are most abundant in cleared places or in the neighborhood 
of the habitations of man. 
The food relations of many of our birds are also peculiar. 
A very considerable number of our Hawks, examined at 
different times of the year, and in different places, have re- 
vealed only a diet of moths, beetles, grasshoppers, locusts, 
leaves and fruit. While just as certainly the genus Herpe- 
