38 THE TONGUES OF WOODPECKERS. 



and thence to such species as the Gila Woodpecker {Melanerpes uro. 

 pygialis, PI. II, fig. 6). Thence through the Three-toed Woodpecker 

 (Picoides, PI. II, fig. 6) and the Ladder-back Woodpecker (Bryohates 

 scalaris, PI. II, fig. 3), we reach the Bedhead Woodpecker {Melanerpes 

 erythrocephalus, PI. II, fig. 2) and California Woodpecker {Melanerpes 

 formicivorus bairdi, PI. II, fig. 1), while between these and the short, 

 brush-tongued Sapsucker (Sphyrapicus, PI. I, fig. 12), there is a gap 

 to be bridged over. 



Considering the tongues in relation to food, we find that those of the 

 various species of Flickers (Golaptes, PI. I, fig. 3) have the fewest termi- 

 nal barbs and the longest dorsal tract of fine points; they are also 

 among the longest. The members of the genus are particularly fond 

 of ants, and the tongue seems especially adapted for probing ant hills. 

 The function of the fine points on the upper part of the tongue seems 

 to be to form a rough surface to which the sticky saliva will readily 

 adhere and to which in turn the ants will be stuck. In this genus the 

 submaxillary salivary glands reach the maximum size in the group. 



The Hairy and Downy Woodpeckers [Dryobates villosus and B, 

 pubescens, PI. I, fig. 4), and also the Pileated Woodpecker (GeopMceus 

 pileatus) feed more or less oh the larvae of beetles ( Coleoptera), and these 

 have sharply barbed tongues, well adapted for spearing grubs or for 

 coaxing them out of their hiding places. Hence it seems extremely 

 probable that other species similarly provided have similar food habits. 

 In these species, and in others with sharply barbed tongues, the dorsal 

 tracts of points vary in shape and extent as well as in the size and 

 number of the points,, but in none are they as long as in the Flicker 

 (Colaptes). The same is true of the submaxillary glands, which are all 

 smaller than in the Flicker. 



The Eed-headed Woodpecker {Melanerpes erythrocephalus, PI. I, fig. 

 9), although having a peculiar tongue, has one which is less evidently 

 specialized than those of other species, and one which suggests the 

 fringed tongues of some finches and other passerine birds. In diet 

 this bird appears to be the most omnivorous of the species examined, 

 eating a large proportion of fruit, or vegetable food, the total amount for 

 some months equaling that of the insect food. The species is evidently 

 fond of grq,sshoppers, but whether or not there is any direct relation 

 between the character of its tongue and that of its food is not evident. 



The Sapsucker (Sphyrapious varius, PL I, fig. 12) drills into the 

 maples, birches, mountain ash, and apple trees, and feeds upon the sap 

 as well as upon the insects which are attracted by it. The tongue may 

 be used in two ways: either the fringe of stiff hairs may serve as a 

 brush, to which a considerable quantity of sap would adhere, or it may 

 serve by capillary attraction to guide the sap from the little pits in 

 which it gathers to the front part of the tongue. 



The tongue of the Sapsucker is much less extensile than that of any 

 other woodpecker examined, and this lack of extensibility is a charac- 



