382 



LIMOSA. 



General 

 facts of dis- 

 tribution. 



Parallelism 

 between 

 God wits and 

 Oyster- 

 catchers. 



cosmopolitan in their range. Their migrations are very extensive, and at some period of 

 the year they visit every part of the World, with the remarkable exception of the Ethiopian 

 Region south of the Equator. 



The Godwits are shore birds, though they often breed far inland where suitable 

 marshes or meadows are to be found. In winter they chiefly frequent the sea-shore, and 

 like many other birds of similar habits they acquire a mud-coloured dress in autumn to 

 enable them to do so with comparative impunity. On migration they follow the coast-lines for 

 the most part ; and we may reasonably infer that when they were inhabitants of the Polar 

 Basin they were accustomed to make short trips along the coasts towards the south during 

 the annual three months' night. When the Glacial ice increased sufficiently to drive them 

 altogether out of the Polar Basin, there can be little doubt that they followed these four 

 coast-lines, with which they must already have been familiar. 



The isolation thus caused indirectly produced the differentiation of the Pre-Glacial 

 species into four good and well-defined species. We may take one more step in the chain 

 of reasoning with tolerable certainty, and assume that of the two groups into which the 

 genus may be divided, Bar-tailed Godwits and Black-tailed Godwits (of each of which both 

 hemispheres possess an example), one group are the descendants of the birds which left 

 by way of the Atlantic, and the other represents the Pacific shore emigrants. The present 

 distribution of the two groups of Godwits ought to throw some light upon their former 

 migrations, inasmuch as birds appear to be very slow in finding new " fly-lines " and very 

 quick in rediscovering old ones. Eortunately for our hypothesis the evidence upon this 

 point is neither meagre nor conflicting. In the North Atlantic the Bar-tailed Godwits 

 are unrecorded from Greenland, Iceland, or the Faroes, whilst the Black-tailed Godwit 

 is recorded from each of the three localities. On the other hand, the Black-tailed American 

 Godwit is said to be very rare in Alaska; whilst the eastern form of our Bar-tailed Godwit 

 was the only species obtained by Stejneger on the Commander Islands, and was found by 

 Dall to breed abundantly at the mouth of the Yukon River in Alaska. Surely these 

 facts have some significance and are not the result of mere accident ! 



There is a remarkable parallelism between the distribution of the Godwits (Limosa) 

 and that of the Oystercatchers {Hcsmatopus). 



The Godwits are divisible into four 

 groups, founded upon two characters. 



Predominant colour of the axillaries and 



under wing-coverts (a) white or (b) 



chestnut or brown. 

 Colour of the tail-feathers (c) black 



with white bases or (d) barred with 



brown and white. 



The Oystercatchers are divisible into 

 four groups, founded upon two 

 characters. 



Colour of the legs and feet (a) red or 

 (b) flesh-colour. 



Colour of the general plumage (c) pied 

 or (d) black. 



