56 
ANAS DIAZI 
DISTRIBUTION 
This rare Mexican species appears to be non-migratory and is apparently confined to the highlands 
of central Mexico. Its status is extremely uncertain, and has been much confused because of the fact 
. that some writers interpret in different ways the various references to Anas obscura in 
iVIczico 
Mexico. Cooke (1906) evidently understands the record of Anas maculosa in Chi- 
huahua as applying to the present species, but this might be questioned, for Mr. Charles Sheldon 
tells me that he shot many “Black Ducks” near Chihuahua City, and that he is not certain what 
species they belonged to. As far as can be determined the present species is resident in the high area 
included in the States of Tepic, Jalisco, Michoacan, Mexico, Puebla, Guanajuato, and probably 
parts of Hidalgo and Zacatecas. Grayson (Lawrence, 1874) found many in pairs at Tepic in June 
and supposed that it bred there, though he saw none as far north as Mazatlan. Sanchez (1877-78) 
has also reeorded it from Tepic, while it has been found by Duges (1869) at Guadalajara in Jalisco. 
Cooke (1906) is authority for the statement that it occurs in Michoacan, but I have been unable to 
discover the source of his information. In the lake region of the Valle de Mexico the species seems 
to be more common than elsewhere, having been recorded from there by Sanchez (1877-78), Villada 
(1891-92) and Herrera (1888). Villada (1891-92) states that it is found in winter in the Valle, and 
as far as known it is a non-migratory bird there. At Lerma, a very high valley northwest of Mexico 
City, Goldman (U.S. Biological Survey) found several specimens of this duck. The type examples 
were taken by Ferrari-Perez (1886) in Puebla at San Ysidoro. He found the species in May. Farther 
north he took specimens at the Laguna del Rosario, Tlaxcala. Mr. W. W. Brown visited the lake 
region near Mexieo City in the fall of 1910 in the interests of the Museum of Comparative Zoology, 
and sent back a series of six males and seventeen females. There are no records of its occurrence in 
Hidalgo, but it has been reported from Guanajuato by both Sanchez (1877-78) and Duges (1869). 
GEOGRAPHICAL RACES 
NEW MEXICAN DUCK or HUBER’S DUCK 
ANAS DIAZI NOVIMEXICANA Huber 
Synonymy 
Anas novimexicana Huber, Auk, vol. 37, p. 273, 1920. 
Anas diazi novimexicana Conover, Auk, vol. 39, p. 412, 1922. 
DESCRIPTION 
Addxt Male: Very similar to Anas diazi diazi, but apparently always to be distinguished by an 
irregular wavy barring of fulvous color on the mantle. In some specimens there is a tendency to a 
darker and more mottled breast. In the series before me are ten undoubtedly adult males, including 
the type. These are very puzzling birds because they are not exactly uniform and show in several 
cases marked Mallard characters. These are most pronounced in specimen No. 26,041, J. E. Thayer 
collection (Las Cruces, Mew Mexico, April 6, 1920). In this bird the under tail-coverts are nearly 
jet black, some of the upper tail-coverts are metallic green and the two central tail-feathers are 
distinctly upturned and very pointed. A few green feathers are present around the back of the head 
and the long scapulars are covered with fine dots, both Mallard characteristics. In specimen No. 
635 (collector’s number) three central tail-feathers are almost black and nearly as upturned as in a 
male Mallard. From a male Mallard in full eclipse plumage this race can be told by its darker under 
surface and barred, rather than plain-colored mantle. 
Iris brown. BiU bright yellow. Legs orange. 
