88 TROPICAL WILD LIFE IN BRITISH GUIANA 



-(Groups found typically in more than one Zone) 

 Ground Low Jungle Mid Jungle Tree-tops 



(0-20 feet) (20-70 feet) (70-200 feet) 



Goatsuckers Goatsuckers Hummingbirds Flycatchers 



Hummingbirds Flycatchers Hummingbirds 

 Tanagers Tanagers 



Mammals permit a similar mode of representation of 

 altitudinal distribution: 



Anteaters Opossums Anteaters Red Howlers 



Armadillos Sloths Beesa Monkeys 



Tapirs Bats 



Peccaries Coatis 



Deer Squirrels 



Cats Marmosets 



Dogs Kinkajous 



Galictis 



Rodents 



Returning to the birds of the jungle. Accepting 1 to 

 10 as the gradation of light from the dimmest part of the 

 jungle to full sunlight, and with the same divisions as a 

 basis, we can form an interesting table of relative percent- 

 ages of dull and brilliant birds : 



Gradation 



/, T . i , ONE THREE FIVE TEN 



of Light 



Percentage 



of Bright 



Birds 08 50 83 



This by no means indicates that all the brilliant birds 

 are conspicuous in their native haunts or that the dull ones 

 are correspondingly protected by their pigment. A quad- 

 rille wren hopping about and filling the low jungle with its 

 wonderful unearthly melody, is a most conspicuous bit of 

 life in spite of its garb of brown and buff. A parrakeet 

 with spots of yellow on vivid green, opalescent in the hand, 

 is but one leaf among a million in the tree-tops. 



