296 



ILEMATOPUS. 



Climatic dis- 

 tribution. 



The distribution of the Oystercatchers is unique, and cannot be made to fit in with 

 any system of geographical or zoological regions. It is so far independent of climate, that 

 every species breeds in two climates, but very often on only one coast of them. The 

 Oystercatchers are distributed as follows : — 



Arctic and Temperate America 1 



Arctic and Temperate Eurasia 2 



Arctic and Temjjerate species — 3 



Tropical and North and South Temperate America . 1 



Subtropical shores of the Galapagos 1 



Tropical and South Temperate America 2 



Tropical and Temperate Africa 1 



Tropical and South Temperate Asia 2 



Tropical and Temperate species — 7 



Species and subspecies of Hamatqpus — 10 



Local distri- 

 bution. 



Geographi- 

 cal distribu- 

 tion. 



The most remarkable fact in this unique distribution is the extended range of H. 

 palliatus. This species is said to breed from Labrador to Patagonia on the Atlantic coast, 

 and from California to Chili on the Pacific coast. No other bird in the family has a 

 breeding-range at all equivalent to this. 



The Oystercatchers must be regarded as belonging to the Temperate Region, within 

 which every species breeds — one third of the species or subspecies breeding also in the 

 Arctic Region, and the breeding-range of the remaining two thirds extending into the 

 Tropical Region. 



The Oystercatchers are almost cosmopolitan in their range. They are strictly shore- 

 birds, but few of them confine themselves to the sea-shore ; they frequent the margins of 

 lakes, the banks of great rivers, and are occasionally seen in other localities inland during 

 migration. Some species are migratory, others resident, whilst some are migratory in one 

 part of their range and sedentary in another part. They are semi-arctic birds, the limit of 

 their northern range corresponding to a considerable extent with the isothermal lines of 

 mean annual temperature. In North-west Europe, where the influence of the Gulf-stream 

 raises the latitude of suitable climate, Oystercatchers breed as far north as lat. 70°, in East 

 Russia and West Siberia up to 66°, but in East Siberia and on the American continent 

 only up to about 60°. In the Southern Hemisphere the southern limit of their breeding- 

 range is determined by the limitation of the land. No Oystercatcher is known to breed 

 within the Tropics on the mainland, but they breed on some of the islands within the Tropics 

 — the Bahamas, the Galapagos Islands, the islands on the north coast of Australia, and 

 possibly elsewhere ; otherwise Oystercatchers are only winter visitors to the Tropics. 



The geographical distribution of the Oystercatchers may be broadly stated as follows : 

 Entirely absent from both the Arctic and Antarctic Regions ; breed in the Temperate Regions 



