204 



TROPICAL WILD LIFE IN BRITISH GUIANA 



FIG 58. HEEL-PAD OF TEN-DAY-OLD ARACARI TOUCAN 

 a. Side view of pad on left leg. b. Bottom view of left pad. c. Bottom view of right pad. 



podal position from whicli it was impossible to shift them. 

 They absohitely refused to make any use of the feet or toes. 

 Indeed, any considerable change of position was impossible, 

 the patagium or web of skin between the tibia and the tarsus 

 being stretched at such tension that the leg could not be 

 extended more than at a right angle or a little over ninety 

 degrees. 



While the nestling hoatzin is a true quadruped, the 

 young toucan is just as certainly a tripod, at least during 

 the first weeks of its existence. 



On the day I secured the two birds I estimated their 

 age at about ten days. There was little or no difference in 

 size between them. One which I kept under close observa- 

 tion showed almost no hint of the coloring of tlie adult. 

 The mandibles were dark slaty horn color along the upper 

 and basal margins, paling toward the cutting edges and at 

 the tip to a light yellow. 



T'he bare, wrinkled skin of the body was pinkish flesh 

 with the feather tracts showing leaden blue. The feet and 

 legs were bright yellowish green. The skin-covered sheaths 



