774 U. S. p. E. E. EXP. AND SUEVEYS — ZOOLOGY — GENERAL REPORT. 



ANAS BOSCHAS, L. 



Mallard ; Green Head. 



,9nas bosclias, Linn. Syst. Nat. I, 17GG, 205.— Fobster, Phil. Trans. LXII, 1772, 383.— Gmelin, I, 538.— Wilson, 

 Am. Orn. VIII, 1814, 112 ; pi. l.rx.- Hon. Obs. 1825, No. 256.— Ib. List, 1838.— Ann. Orn. Biog. 

 Ill, 1835, 164; pi. 221.— Ib. Syn. 276.— Ib. Birds Amer. VI, 1843, 236; pi. 385.— F.yton, Mon. 

 Anat. 1838, 140. 



Jlnas (Boschas) boschns, Jenyns, Man. 233. 



^nas adunca, L. Syst. Nat. I, 1766, 206. — Gm. I, 538 ; monstrous variety. 



Jlnas domestica, Gmelin, I, 1788, 538. 



Jlnas {Bnschas) domeslica, Sw. F. Bor. Am. II, 1831, 442.— Nuttall, Man. II, 1634, 378. 



" Anas bicolor, Donovan, Br. Birds, IX; pi. 212." (Supposed hybrid with Cairina nuschala, or muscovy duck. 

 Jenyns.) 



" Anas purpurea liridis, ScHiKZ." (Supposed hybrid with Cairina moschala. Bonap.) 



Anas maiinin, Goese, Birds Jam. 1847, 3119. (Suppo-ed hybrid with Cairina moschala) 



Fuligula viola, Bell, Annals N. Y. Lyceum, V, 1852, 219. New York. (Supposed hybrid with Coii-i7ia moschala.) 



Anas glocilans, AuD ; pi. 338. 



Anas breioeH, Ai7d. Orn. Biog. IV, 1838, 302 ; pi 338.— Ib. Syn. 277.— Ib. Bird's Amer. VI, 1843, 252 ; pi. 387. 



Anas audubonii, Eon. Geog. Li-t, 1838. The tliree last names are based on the same specimen, supposed to be a 

 hybrid between Anas boschas and Chaulela^mus tlreperus, possibly with Aytliya vallisneria. 



Mallard, Pennant, Arctic Zool. II, 563.— Lbth. Syn. III,ii, 489. 



Sp. Ch. — Male. Head and nerk bright grass green, with violet gloss, the top of t!ie head duller ; a white ring round the 

 middle of the neck, below which and on the fore part and sides of tlie breast the color is dark brownish chestnut. Under parts 

 and sides, with the scapulars, pale gray, very finely undu'ated with dusky ; the outer scapulars with a brownish tinge. Fore 

 part of back reddish brown ; posterior more olivaceous. Crissum and upper tail coverts black, the lailer with a blue gloss. 

 Tail e.xternally white ; wing coverts brownish gray, the gnater coverts tipped first with white, and then more narrowly with 

 black. Speculum purplish violet, terminated with black ; a recurved tuft of featheis on the rump. 



Female with the wing exactly as on the male. The under parts plain whitish ochrey, each feather obscurely blotched with 

 dusky. Head and neck similar, spotted and streaked with dusky ; the chin and throat above unspotted. Upper parts dark 

 brown, the feathers broadly edged and bande 1 with reddish brown parallel with the circumference. 



Length of male, 23 ; wing, 11 ; tarsus, 1.70 ; commissure of bill, 2.50. 



liab. — Entire continent of North America and greater part of Old World. 



A large duck, mucli exceeding the mallard in size, but quite similar in general appearance, 

 is occasionally shot in the United States and in Europe, and described by the various names 

 given in the synonomy. It is generally supposed to be a hybrid with the muscovy, Cairina 

 moschala, although, from the constancy of its markings and the absence on the face of the 

 peculiarities of the muscovy, it may be questioned v?hether, after all, it be not entitled to 

 specific rank. The Anas breweri of Audubon is diiferent from this form, and may, possibly, be 

 a hybrid with the gadwall, as suggested by its describer. 



This species is generally considered as identical with the barn-yard duck, and presents one of 

 the few cases where the original is well known of a domesticated animal. A difierence 

 between the wild and tame mallard, according to Giraud, is to be found in the much broader, 

 harder, and more horny feet of the latter. 



