MALLARD 

 ( Anas platyrhynchos ) 



[DA: Graand, DU: Wilde eend , PI: Heinasora, FR: Canard col-vert, GE: Stockente, 

 IC: Stokkond, IT: Anitra selvatlca, Gerraano reale; JA: Magamo, NW: Stokkand, 

 PO: Krzyzowka, PR: Pato-real, SP: Pato comun, Anade real; SW: Grassand] 



GENERAL DISTRIBUTION 



In North America, the Mallard breeds from Alaska and northern MacKenzie 

 across Canada to the southern shore of Hudson Bay and southern Quebec, south to 

 central California, central Nevada and Utah, New Mexico, Oklahoma, Missouri, 

 Ohio, and Virginia, occasionally farther south (AOU 1957, Bellrose 1976). In 

 recent years Mallards have been released, intentionally or accidentally, in 

 many areas south of the historic range; many of these have bred, and the natur- 

 al range is difficult to determine. In southern Arizona and New Mexico and 

 western Texas, typical green-headed Mallards intergrade with a monomorphic fe- 

 male-plumaged population (A. £. diazi ) which is resident in the central Mexican 

 highlands (Hubbard 1977). In winter the Mallard occurs throughout most of the 

 United States and in Mexico (AOU 1957, Palmer 1976a). Mallards are also wide- 

 spread through Eurasia and there is a subspecies in coastal Greenland (AOU 1957, 

 Palmer 1976a, Cramp et al. 1977). 



The North American estimated breeding population of the Mallard ranged from 

 about 6.1 (1965) to 14.5 (1957) million birds between 1955 and 1969, with an av- 

 erage of 9.6 million. The late summer population in North America during these 

 years averaged about 19.5 million, and the harvest was about 3.5 million (Ander- 

 son and Henny 1972). The species is common in all the southeastern states (Map 

 11). The Mississippi Flyway is an important corridor for the Mallard, and of 

 the estimated 3.1 million birds (the average in 1960-1970) using it annually, 

 about 400,000 wintered in the coastal Louisiana marshes. Many fewer birds use 

 the Atlantic Flyway, but of those that do, about 110,000 winter in southeastern 

 South Carolina and 40,000 in the Chesapeake Bay region (Bellrose 1976). 



SUSCEPTIBILITY TO OIL POLLUTION 



Mallards have suffered casualities from coastal oiling incidents (Smith 

 1973, Table 3). They are also prone to problems at inland oil-sumps (King 1953). 

 In the Caspian Sea region, Mallards have been the inland species most affected 



Taxonomic note: In general, this account deals only with the "typical" green- 

 headed Mallard, although the North American range includes the "Mexican Duck", 

 Anas p. diazi , formerly recognized as a species. The Mottled (including Flor- 

 ida) Duck, A. f ulvigula , although treated by some authors (Johnsgard 1975, Bell- 

 rose 1976) as one or more subspecies of Mallard, is treated here as a distinct 

 species, as are various insular populations, well outside the geographic scope 

 of this report, that associate with the Mallard in some winters. 



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