xxiv INTEODUCTION. 



Chaulelasmus is confined to the Northern hemisphere ; Poecilonetta is com- 

 mon to South America and Africa, south of the Great Desert ; Elasmonetta, 

 pecuhar to New Zealand ; Nesonetta, to the Auklands ; Malecorhynchus, to 

 Austraha and Tasmania ; Heteronetta to the Southern portions of South 

 America. The cosmopolitan genera are Nettion, Anas, and Spatula; whilst 

 Querquedula is found over the Northern hemisphere and South America, and 

 Dafila is a cosmopolite with the exception of Australia and New Zealand. 

 Following these, we have the Diving Ducks and Eiders (Fuligulinse) . These 

 Ducks are almost exclusively Northern hemisphere birds, with the exception of 

 the genus Nyroca which is cosmopolitan; Metopiana (one species) which is 

 confined to South America, one of the five species of Fuligula which inhabits 

 New Zealand, the Aukland and Chatham Islands, and Tachyeres (one species) 

 inhabiting the Strait of Magellan and the Falklands. Many of the species are 

 arctic or sub-arctic in distribution during summer, as details of their geographical 

 area in the present volume will show. Our last British subfamily contains the 

 Mergansers and Smews (Merginse). Of the three genera that compose it, 

 Lophodytes (one species) is confined to North America, Mergus (one species) is 

 exclusively Paltearctic, whilst Merganser (seven species) is of wide distribution, 

 ranging over the Palsearctic and Nearctic regions, and portions of the Neotropical 

 and Oriental regions, together with the Aukland Islands in the South Pacific. 

 Some of the other subfamilies are remarkable for their geographical distribution, 

 such as the Merganettinse with representatives in New Zealand and the Andes. 



Now as regards the migrations of the Game Birds and- Wild Fowl. Taking 

 the various groups of birds dealt with in the present volume in their sequence, 

 we have first to consider the migrations of the Pigeons. So far as concerns the 

 few British species we have little of exceptional interest to record, although the 

 annual movements of some birds of the Pigeon tribe in other parts of the world 

 are upon such a scale that elevate them to the highest class of migrational 

 phenomena. To illustrate this we have only to allude to the marvellous migra- 

 tions of the Passenger Pigeon of the New World. Unfortunately the progress of 

 civilization in North America has been synchronous with the almost complete 

 extermination of this interesting bird, which now only manages to survive in the 

 least populated areas, and even there in numbers that can only be described as 

 remnants. This species is an abnormal migrant to the British area, and we have 

 already dwelt at some length upon its migrational movements. The typical 

 Pigeons can scarcely be classed as birds of strong migrational movement, season- 

 flight perhaps reaching its greatest development in the Turtle Dove and allied 

 forms. Migration becomes much more pronounced amongst the Sand-Grouse, 

 and in these birds it is often of a strongly marked nomadic or irruptic character. 

 Two of the species are known as cold season visitors to India, and one or two of 

 the South African Sand Grouse appear to have well-defined migrations. 



There is more regular migration among the Game Birds than is perhaps 



