180 TROPICAL WILD LIFE IN BRITISH GUIANA 



safety of the young bird must be compensated by constant 

 activity in the renewal of these structures. 



When we find the claws in a three-quarter grown bird 

 worn to stubs with no trace of the hooked tip remaining, 

 or perhaps with one claw just shed, and then in fully adult 

 birds with the fresh, sharp, curved talons deep hidden among 

 the long wing feathers, it seems as if Nature had for once 

 nodded, and preserved a character beyond the scope of its 

 usefulness. 



The first volume of a book on "The Birds of British 

 Guiana," by Charles Chubb has just appeared. Mr. Chubb 

 has not had the opportunity of observing living hoatzins and 

 this enforced writing at second hand has resulted in a num- 

 ber of errors which should be corrected. First as regards 

 the two figures. That of the head of the bird shows the wav- 

 ing crest too flattened. The bird seems to have little or no 

 control over the dermal cranial muscles, and the long, dis- 

 integrated crest feathers are always raised, standing almost 

 erect and giving to the bird a wild, startled appearance, even 

 when it is sleepy and about to put head under wing. Figure 

 twelve, the wing of the young bird, is quite wrong in anat- 

 omy, both in the number of claws, the position of the thumb 

 and the general proportions. In the measurements of the 

 adult bird the total length is taken evidently from a dried 

 skin, as it is given as 555 millimetres. Even a three-quarters 

 grown bird measures at least 590 mm., while a fully adult 

 hoatzin is not less than 620 mm. in length. In his extra- 

 limital range Chubb makes no mention of either Venezuela, 

 Dutch or French Guiana, in all of which countries hoatzins 

 are well known to occur. 



The nestling hoatzin shown in my frontispiece photo- 

 graph was about two weeks old and was taken in a nest on 

 the lower Berbice River on May 26. The following notes 

 characterized all the young birds of this age which I ob- 

 served or photographed. The short down already showed 

 the pigment patterns of the adult, the sides and flanks being 



