190 THE STORY OF THE BIRDS 



for instance, both walk and hop ; Thrushes not 

 only walk and hop, but occasionally run as well. 

 We often find considerable difference in the gait 

 of very closely allied birds. A Chaffinch not 

 only runs, walks and hops, but a Sparrow in- 

 variably progresses by the latter means alone. 

 The most expert runners amongst the Passeres 

 are the Wagtails, Pipits, and Larks. A hopping 

 gait is certainly the most prevalent amongst 

 small Passerine birds. Woodpeckers, when they 

 do visit the ground, which in some species at 

 all events is much more frequently than is 

 generally supposed, progress in long hops ; but 

 on the trunks of trees they run and walk only, 

 supported by the stiff tail. The Passerine 

 Creepers progress in a similar way. We may 

 conclude this portion of the subject by a brief 

 allusion to the various actions of aquatic birds. 

 We pass over the plunging of Gannets and 

 Terns and other species, for that scarcely 

 comes within the scope of the present subject, 

 being connected with flight. Aquatic birds, 

 then, may either swim or dive. The birds that 

 dive of course can swim equally well, but there 

 are many birds that swim yet never dive. Even 

 amongst the Ducks we have two special groups ; 

 one distinguished for diving, the other for 



