PERCHERS AND CLIMBERS 17 



the Mandarin Duck and Andaman Teal (Ncttium 

 albigulare) slide right over and off a perch on 

 which they had tried to alight. Only Cormorants 

 and Darters among waterfowl seem at all at home 

 in trees, and these have a powerful gripping foot 

 with well-developed hind-toe, and more freedom 

 in the legs than is usual in diving birds. 



In travelling along a perch, the most active, as 

 well as the clumsiest perchers, are apt to move 

 sideways ; thus the lively Sparrow and the heavy 

 Cormorant both sidle on a bough, though the 

 ground-living Fowl and the arboreal Parrot walk 

 foot over foot, for which the in-turned feet of the 

 latter are particularly suitable. The most active 

 birds at this pole-walking are the Guans and the 

 Touracous, which run along boughs like squirrels, 

 and at the same time can leap long distances from 

 one perch to another; but on the whole, the 

 more active the bird, the more apt it is to adopt 

 the sidelong gait on a bough, often turning round 

 with each hop, a method of procedure which seems 

 calculated to make it giddy. 



In climbing, several methods are employed ; 

 Parrots, as every one has seen, hook themselves 

 along with their beaks as well as their claws, though 

 they do not do this in the wild state as much as one 

 would think from seeing them caged ; and Cross- 

 bills, those Parrot-like Finches, climb in the same 

 way. Woodpeckers and typical Creepers, however, 

 climb quite differently from Parrots, but like each 

 other, though the last group are Passerines and not 

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