56 THE MIGRATION OF BIRDS. 



are presented in such species as the Rufous Warbler 

 (Sylvia galactodes), the Woodchat Shrike {Lanius 

 nifus), the Woodcock {Scolopax rusticola), and 

 the Golden-eye {Clangida glaucion). Moderate 

 journeys are represented by the Great Reed Warbler 

 {Acrocephalus turdoides), the Turtle Dove {Turtui- 

 auritus), the Crane (Gnis communis), the Jack 

 Snipe {Scolopax gal/iuula), and the Mallard {Anas 

 hoschas). Amongst birds whose migrations are 

 decidedly long, we may note the Wheatear {Saxi- 

 cola cenanthe), the Cuckoo {Cuculus canoriis), the 

 Corn Crake {Crex pratensis), and the Greenshank 

 {Totanus glottis). The most extended flights of 

 all known birds are performed by such birds as the 

 three species of British Swallows {Hirundo rustica, 

 Chelidon nrbica, and Coti/Ie riparia), the Turnstone 

 {Strepsilas interpres), the Gray Plover {Cliaradrius 

 helveticus), the Sanderling {Calidris arenana), the 

 Knot {Tringa canutus), and the Pectoral Sandpiper 

 {Tringa pectoralis). The following table will serve 

 to demonstrate the gradated character of migration. 

 The mileage is approximate, and represents a course 

 almost due north and south ; but few, if any species, 

 however, travel so direct, so that the actual distance 

 traversed may be in excess of the figures on the 

 following page. 



From the above facts I think that we may very 

 fairly make the following deductions. First, that 

 incipient and short migration flight indicate move- 

 ments to correspond with comparatively small 

 variations of climate necessary to requirements and 



