The Gait and Flight of Birds 319 
Unlike leaping mammals, birds which 
hop never attain any great speed, all the 
swift species being runners. The Ostrich 
has the reputation of being the swiftest of 
all running animals; but the Road-Runner of 
California (Geococcyxz mexicanus), a ground- 
cuckoo no bigger than a magpie, is said 
to be able to keep ahead even of a horse- 
man for many hundred yards. As a rule, 
however, the best runners outside the Ratite 
group are confined to the Bustards, Game- 
Birds (Phasianide), Tinamous and Plover-lke 
Vig. 4. Hornbill hopping. forms, and these have the hind-toe reduced 
or absent. 
The actions of birds on trees are usually correlated with their movements on the 
ground, whether they spend much or little time there; thus, birds which hop on the 
ground not only jump from one branch to another, but if moving along a branch 
travel with sidelong hops. A bird which walks, on the other hand, will, although 
it may jump from one bough to another, nevertheless travel “hand over hand” along 
a bough if it has any distance to go. The different actions of a Jay and Touracou 
in a tree exemplify this (Fig 5). 
Parrots not only walk along the boughs, but hook themselves from one to another 
with their bills, and so, among the finches, do the Cross-Bills (Fig. 6). Lories, 
however, in accordance with their hopping gait on terra firma, hop and sidle much 
among the boughs, and comparatively seldom call in the assistance of their bills. 
Something must be said about the movements of birds when swimming. This 
accomplishment most of them apparently possess, but as non-aquatic birds usually propel 
themselves by striking with their wings, they soon become draggled and exhausted, and 
drown in spite of their lightness, which ensures thei floating. Those which use their 
legs like waterfowl, as the waders do when out of their depth, manage well enough; 
the wild turkey, when its limited powers of flight have failed to take it across a wide 
river, gains the shore in this way. The great flightless birds are also good swimmers. 
I have heard of an immature Cassowary reaching land after a four miles’ swim in a 
rough sea; and these birds and the 
Emu and Rhea are known readily 
to Gross rivers. 
Of birds which swim habitually, 
the feet, which are usually webbed 
or lobed, are the agents of pro- 
pulsion on the surface, and usually 
strike alternately, the automatic 
closure of the foot as it 1s drawn 
forward lessening the resistance to 
the water, while it is expanded for 
the back-stroke. The diving water- 
fowl usually swim low, more or 
less, ike the Cormorant (Fig. 7), 
which is almost an extreme example, 
although its relative, the Darter or 
Snake-Bird (Plotws) shows only 
the serpent-like neck above water. Vig. 5. Touracou running along bough. 
