Skull of Woodpecker, showing bones of tongue.
a. Upper end of windpipe and gullet.
Hyoids of Sapsucker and Golden-fronted Woodpecker.
Not all woodpeckers have tongues precisely like this. The sapsucker’s is the shortest of any, and reaches barely beyond the hinge of the jaws. In the Lewis’s woodpecker and others of his genus the branches of the hyoid extend part-way up the back of the skull but in the kinds that live principally upon borers they are very long and resemble the flicker’s in arrangement. The only other North American birds that have a tongue built upon this plan are the hummingbirds, in which also it is extensile. The flicker, in proportion to his size, has the longest tongue of any bird known.
XV
HOW EACH WOODPECKER IS FITTED FOR HIS OWN KIND OF LIFE
We have studied the woodpeckers at some length: first, what all of them do; next, what some that are peculiar in their ways do; lastly, how each is fitted for a particular kind of life. At first we were inclined to think they were all alike; but now we begin to see that there are very real differences between them,—in tails, feet, bills, and tongues, and at the same time in their food and habits.
The flicker’s tail is less sharply curved than that of any other woodpecker,—a sign that he is probably not exclusively a tree-dweller; his bill is curved and rounded, a pick-axe rather than a drill,—an indication that he does not dig for grubs; his feet do not tell us much; but his long extensile tongue shows that, whatever he feeds upon, he seeks it in holes. We find a tongue like this in no other bird, but among mammals the aard-vark, the ant-bear, and the pangolins are all similarly equipped, and all live on ants which they extract from their mounds and burrows in hundreds by means of these round, sticky, and extensile tongues. This is precisely the way the flicker gets his living. He lives principally upon the ground or near it, pecks very little except when digging his nest, and feeds largely upon ants, thrusting his head into the ant-hills and drawing out the ants glued to his tongue rather than speared by it. As he has been known to eat three thousand ants for a meal, we see how much easier this is than spearing them one by one.