218 RIVER AND POND DUCKS 



a wide range but is more abundant in the central and western portions 

 than in the east. It is essentially a fresh water duck of the sloughs, 

 marshes, streams, muddy ponds, and sluggish creeks. The prairie regions 

 of the middle west afford the type of range which it prefers and to which 

 it is best suited. 



Except for its huge bill, the Shoveller is markedly like the Blue- 

 winged and Cinnamon Teals in structure, coloration and habits. The 

 flight of all three is erratic, and all are warm-weather birds, being early 

 migrants in autumn and late in spring. In all the species of Shovellers as 

 well as in these two teals the wing-coverts are blue and the wing mark- 

 ings similar. The South American Shoveller is coloured as is the Cin- 

 namon Teal, and the heads of the Australian and New Zealand varieties 

 are identical with that of the Blue-winged Teal, even to having the same 

 white crescent between the bill and the eye. 



The drake is a strikingly handsome and beautiful bird, though its 

 disproportionately large bill gives it a somewhat top-heavy and ungrace- 

 ful appearance. No other duck possesses a bill like that of the Shoveller 

 (fig. 43). The bills of all ducks have comb-like "teeth" or lamellae 

 along the edges of the upper and lower mandibles; in the case of the 

 Shoveller, however, the bill is highly specialized and these teeth reach 

 their greatest degree of development. In addition, the roof of the mouth 

 and the tongue are supplied with sensitive nerves of touch and taste. 

 The bill is exceptionally large, the average length being about two and 



three-quarter inches and it widens from about 

 five-eighths inch at the base to about one and 

 one-quarter inches near the tip. This specially 

 designed bill places the Shoveller at the head of 

 the class of surface feeders. It is in fact more 

 essentially a surface feeder than any of the 

 others, paddling quickly along with its head half 

 submerged, taking into its mouth the tiny par- 

 ticles it encounters, tasting them with its sensi- 

 tive tongue, and sifting out through the lamellae 

 of its bill such as may not be wanted. This is 

 FIG. 43. its usual method of feeding, though it often 



Bill of Shoveller slushes mud from the bottom through its 

 bill, retaining the edible and rejecting the 



worthless remainder. The broad bill, the multiplication of the bristle- 

 like, straining lamellae, and the elongation of the intestine of this species 

 are specializations for the nutritive utilization of minute organisms, such 

 as may be found in bottom ooze. While the Shoveller takes more of this 

 bottom food than any other duck, a relatively small percentage of its diet 

 is actually obtained from this source. Shovellers are less given to this 

 method of bottom feeding than is popularly supposed or than is implied 

 by their local names of "mud duck," "mud lark," and 'mud shoveller." 

 Of the surface-feeding methods of the Shoveller, Forbush (1929) 

 says: "Three or four Shovellers will form in line following one after 



