ANSER FABALIS SIBIRICUS 99 



(17) ANSER FABALIS SIBIRICUS. 

 MIDDENDOEFF'S GOOSE. 



Melanonyx arvensis sibiricus, Alphcraki/, Geesr, p. 104 (1905) (Taimyr). 



Anser middendorffl, Sec-itz. Turkes. Jn-otn. p. 70 (1873) ; Oate^, 

 J. B. N. H. S. xvii. p. 45 ; Alpheraky, ibid. p. 599 ; Buturlin, ibid. 

 p. 604; id Field, Nov. 17, 1906; Oatcs. Gaiiw-B. ii, p. 76; Stuart 

 Bakei; Indian Ducks, p. 82 (1908). 



Anser serrirostris middendorflS, Sah-adoh, Cat. B. M. xxvii, p. 102. 



Anser fabalis sibiricus, Hartert. Vuij. Pal. p. 1286 (1920). 



Description. Adult Male.—" Head and ueck grey-brown for tlie most 

 part, with a strong rufous, coffee, or grey-bay tint. A male from Amurland 

 has even a golden-buff colour on the head and neck, and apparently such 

 examples are far from being of rare occurrence locally in East Siberia, as 

 indicated by the name, ' Yellow-Headed Goose,' met with among native 

 appellations in Transbaikalia. All these various tints are evidently of 

 accidental origin, and are just as often present in different individuals as 

 absent. They are doubtless caused by the same factors as the rusty 

 or yellow tinges on the heads of swans, ducks, and other species of geese. 



" In the rest of the plumage, except for a more uniform dark-brown 

 colouring on the upper surface of the body, tlie eastern form does not differ 

 from the typical. Even in dimensions, with the exception, of course, of the 

 bill and feet, M. arvensis sibiricus almost agrees with large examples of 

 M. arvensis." (Alphiraky.) 



Bill black, with a ring of yellow-orange round the apical portion of both 

 mandibles behind the nail. In most cases this is quite narrow, though it 

 may be found to extend as far back as the anterior edge of the nostril 

 in a few specimens, but never, as in A. fabalis fabalis, back to the edge of 

 the forehead. 



Alpheraky gives the length of the culmen as never being less than 

 2'91 inches in adults, and extending to as much as 3'26 ; and Buturlin 

 gives the smallest measurement he has found in this bird as 2'87, and 

 in the same place says that he has found specimens of fabalis with culmen 

 exceeding 2'75 inches. 



Middendorff's Goose is the Eastern form of fabalis, the Bean-Goose 

 and only differs from that bird, except as noted above, in having a larger 

 bill and in having less yellow on it. 



