Chapter III: Part 3

When we propose a change in nature it is wise to inquire whether our improvement has not been tried before and to learn how it worked. How many kinds of birds have we that use their tails for a support? What are their habits and what sort of tails have they?

Besides the woodpeckers we have but two kinds of land birds that prop themselves with their tails,--the swifts and the creepers. The creeper has a tail very much like the woodpecker's as it is; while the chimney swift's is precisely like the woodpecker's as we thought it ought to be. But we observe that while the creeper's habits are almost precisely like the woodpecker's,--so much so that when we first make his acquaintance, some of us will be sure we have discovered a new kind of woodpecker,--the chimney swift has but one habit in common with the woodpecker, that of clinging to an upright surface and propping himself by his tail. If the bird with the tail most like the woodpecker's has the woodpecker's habits, is it not a fair inference that this form of tail is better fitted to this way of living than the other would be?

Next, what variations in shapes do we observe among the woodpeckers themselves? The logcock and the ivory-billed woodpecker have the longest tails--because they are the largest birds. When we compare the length of the tails with the length of the birds we are surprised at the results. On measuring sixteen species, representing seven genera, I find that the tail is from three tenths to thirty-five hundredths of the entire length; that it is, in proportion, as long in the flicker as in the ivory-bill, as long in the downy as in the logcock, and longer (in the specimens measured) in the almost wholly terrestrial flicker than in the wholly arboreal logcock. Without much more study all that we can safely infer is that the woodpecker's tail is not far from one third the length of his whole body measured from the tip of the bill to the tip of the tail. Probably this is the proportion most convenient for his work.

All woodpeckers' tails agree in one particular: they are rounded at the end. At first sight we would say that some are but slightly rounded and others very deeply graduated; but as nearly as I can determine this is at least partly an optical illusion, explained by the great difference in the shape of the feathers making up the tail, which in some, as the flicker, are very broad and abruptly pointed, and in others taper gradually to the end and are very narrow for their length. The larger birds naturally appear to have longer tails, and the effect of narrow feathers is to make the tails appear longer and more sharply graduated than they really are. This diagram shows the shape of the curve in six species, and indicates that, while the curvature is less than we might expect, it bears some relation to the bird's way of living; for we see that the strictly arboreal woodpeckers have more pointed tails than the terrestrial species, and that the amount of gradation bears a direct relation to the amount of time spent upon the tree-trunks.

There is a third difference, the shape of the individual feather, to which we shall refer again; but now we wish to examine the uses and meaning of the curved end.

Diagram of curvature of tails of Woodpeckers. Drawn to scale.

_a_, _a_, point of insertion in
rump.

_a_, _b_, outer tail feather.

_a_, _c_, middle tail feather.

If the outer tail feather were of the same length in all cases, the curve at the end of the tail would be represented by the dotted lines.

1. Flicker.

2. Red-headed Woodpecker.

3. Downy Woodpecker.

4. Logcock.

5. Central American Ivory-billed
Woodpecker.

6. North American Ivory-billed
Woodpecker.

I will show you how to prove this point so that you may be satisfied about it even if you should never see a woodpecker. We will make a little experiment, so simple that even a child can understand it.

First, how many shapes can any bird's tail have? It may be one of three general patterns, and it can be nothing else unless we combine those patterns. It may be square across the end, it may have the middle feathers longest, or it may have the outer feathers longest. To one of these patterns every form of birds' tails may be referred; you can invent no other shape.

Let us assume that you know nothing whatever of a woodpecker's tail except that it has ten feathers, is used as a prop, and is held at an angle of thirty or forty degrees with the tree-trunk. Now, take three strips of paper of the same width and length, and of any size not inconveniently small. Fold them all down the centre. Cut one square across; cut one with a rounded end and the third with a forked end, making them of any shape you please so long as the three papers are of the same length. To give our models a fair test they must be of the same width and length. Next, pin a sheet of paper of any size you please into the form of a cylinder and stand it on end to represent a tree-trunk. Then fit the patterns to the tree-trunk and see which is the form that would give the most support.

But first, in how many ways is it possible for a bird to use his tail as a prop? He may of course hold it open or closed; and the open tail may be held in a single plane, "spread flat," as we say; or curved up at the edges, like a crow blackbird's; or curved down at the edges. And the closed tail may be held in a single plane; or, by dropping each pair of feathers a little, in several planes. Thus we see there are five positions in which each shape may be held against the cylinder of paper. Try each one against it, holding it first in the open positions and then after folding the paper like a bird's tail with the outer feathers underneath, in the closed positions. The size of the model tree-trunk and the shape you cut your curves will make the results vary a little, but you will be surprised to observe, if your models are not too small, how many times you will get the same answers. Note the number and position of the pairs that touch:

_Spread._ _Square end._ _Forked end._ _Round end._

one plane, varies varies middle pair
curved up, middle pair middle pair middle pair
curved down, all all all
_Closed._
one plane, outer pair outer pair middle pair
different planes, outer pair outer pair all

Which shape brings the most feathers into use in all positions? Which positions bring most feathers into use? We see at once that the rounded end has a decided advantage, that the middle pair of feathers is used in all possible positions, that the pair next outside is the next important, and that the spread tail curving downward at the edges and the closed tail in different planes are the two shapes which give the best support. There is therefore a reason for the rounded end which we said was the rule among the woodpeckers.

Our little experiment is what we call a _deduction_. It shows us what we ought to expect under certain imaginary conditions. But it does not show us what actually exists, so there often comes a time when our deductions are faulty because Nature has done some unexpected thing, as when we found the single exception of the logcock's foot upsetting a fine theory of ours. A deduction must always be compared with facts, and is worth little or nothing if a single fact of the series we are studying is not explained by it. This time all the facts do agree; for I had, before we made our experiment, examined the tails of every species of woodpecker ever found in North America, and there was no exception to the rounded end. I had already drawn my conclusion that this form was better adapted to life on a tree-trunk than the square or the forked tail would be, reasoning by a different process called _induction_. An induction examines many, and, if possible, all the facts before drawing any conclusion; a deduction examines the facts after the conclusion is reached. There is no hard-and-fast line between the two kinds of reasoning, but we may say that a _deduction is reasoning out a guess and an induction is guessing out a reason_. Deductions are easier and quicker; inductions are surer, and in preparing them we often make other discoveries.

The rounded tail is no doubt the best; but we have yet to decide whether the sharper curve is more advantageous than the lesser curve, as we thought probable from our observations. And there is still another deduction from our experiment which we did not make. If in the rounded tail the middle pairs of feathers do most of the work, and if use increases the size and efficiency of a part, which is almost an axiom in science, we should expect to find the middle tail feathers not only strongest in all woodpeckers but also strongest in increasing ratio in the species that use them most. To determine this we must study the use of the tail and the structure and shape of the individual tail feathers.

We should remark, perhaps, that the woodpecker's tail is always composed of twelve feathers--ten pointed rectrices and two tiny abortive feathers so short and so hidden that no attention is paid to them. The ten principal feathers are arranged in corresponding pairs numbered from the outside to the centre as first, second, third, fourth, and fifth pairs.

In the flickers all ten feathers have wide vanes and are similar in everything but the shape; all are more or less pointed. The flicker's tail looks and feels very much like that of any other bird except that the shafts are stiffer and the vanes contract to an acuminate tip. But as we take up the other species we notice a change, not only in the shape of the feathers but much more in their texture and in the difference between the various pairs. While in the flicker four pairs out of five are pointed and all are rigid, in the downy and the hairy three pairs out of five seem to be too soft to give any support, the sharp points have disappeared, and the tail has lost much of its stiffness. The two middle pairs of feathers are the only ones capable of doing much work and they are wavering and infirm at the tips where we should expect them to be strongest. In the logcock it is about the same,--two pairs are apparently unfit for work, one pair is infirm, and the two middle pairs are compelled to give all the support, except the little contributed by the third pair. In the ivory-billed woodpecker the two outer pairs are of no assistance and the three central ones do the work, and here again we find the base of the rectrices rigid and inflexible and the last fourth of their length weak and yielding. But what a difference in the individual feather! It is well able to do all the work; for, except for that weak tip which we cannot now explain, it is one of the toughest and strongest feathers to be found. The shaft is broad and flat, as elastic as a watch-spring; it looks like a band of burnished steel as it runs down between the vanes. And the vanes themselves are of a very curious pattern. They curl under at the edges so that we do not see their whole width, and the barbs crowd so thickly upon each other that they over-lie until they present an edge three or four broad. Indeed, the under side of one of these tail feathers reminds one of nothing so much as of the under side of a star-fish's arm with its two long lines of ambulacral suckers on each side of a central groove, so thickly do the spiny vanes of these strong rectrices over ride and crowd together. These spines lay hold of the bark of the tree, rank after rank, hundreds of bristling points that cannot be dislodged except by a forward motion of the bird or by lifting the tail. Compared with this, the spiny points on the flicker's tail were a poor invention. This device, which takes hold like a wool card, or a wire hair-brush, cannot slip from place. We begin to see, too, the use of that weak and flexible tip; it is to press down upon the tree-trunk a flat surface sufficiently large to hold hundreds of these little spiny points against the bark. The ivory-bill braces against this with the stiff upper part of the shaft and has a support that will not slip. The upper part of the shaft acts like a spring also, and adds tremendous force to the blow of the bill. Watch a hairy woodpecker when hard at work and see how his legs and tail form a triangular base by bracing against each other, and how his blow is delivered, not with the head alone, but with the whole body, swinging from the hips, the apex of the triangle on which he rests. He swings like a man wielding a sledge hammer, and to the strength of his neck adds the weight of his body, the spring of his tail, and the momentum of a blow delivered from a greater height. When the little hairy woodpecker does so much with his weak body, we can imagine what great birds like the logcock and the ivory-billed woodpecker, with their tremendous beaks, their huge claws, their springy tails, and their great physical strength can do. They are magnificent birds, the terror of all the grubs that hide in tree-trunks.

One point we have left unexplained: What is the advantage, if there is any, in the sharper curve to the tails of the arboreal woodpeckers? It is a simple question. The curve is caused by the unequal length of the tail feathers; each tail feather is a prop, and by their inequality they become props of different lengths. Now ask any carpenter which will best support a tottering wall--props all of the same length set at the same angle, or props of different lengths set at different angles? His answer will help you to solve the problem. But if a little is good, why are not all the pairs used as props? Partly, perhaps, because the woodpecker is always crowded for houseroom, and while he must have tail enough, he cannot afford to have any which he does not use. Did you ever think what an inconvenience any tail at all must be in a woodpecker's hole?

XIV

THE WOODPECKER'S TOOLS: HIS TONGUE

We have seen how the woodpecker spears his grubs: now we will study his spear.

There are many interesting points about a woodpecker's tongue, and they are not hard to understand. If a woodpecker would kindly let us take hold of his tongue and pull it out to its full extent we should be afraid we were "spoiling his machinery," for the tongue can be drawn out almost incredibly--between two and three inches in a hairy woodpecker and more in a flicker. A strange-looking object it is, much resembling an angle-worm in form, color, and feeling; for it is round, soft, and sticky, except at the flat, horny, bayonet-pointed tip, and as it lies in the mouth it is wrinkled like the wrist of a loose glove; but it grows smaller and smoother the more we pull it out. Evidently we are only drawing it into its skin. But where does so much tongue come from? Does it stretch like a piece of elastic cord? Or is a part hidden somewhere? And if so, where is it kept?

_a._ Cerato-hyals, fused and short.
_b._ Basi-hyal, long, slender.
_c._ Cerato-branchials.
_d._ Epibranchials.
Basi-branchial is wanting.

These questions are answered by studying the bones of the tongue, for without bones it could not be guided as swiftly and surely as it is. Indeed, all tongues have bones in them, as you will discover by cutting carefully the slices near the root of an ox-tongue; but no other creature has such long and elaborate tongue-bones as some of the woodpeckers. They are the slenderest and most delicate little bony rods, joined end to end, but not really hinged nor needing to be, because they are so elastic. Here are the bones of a flicker's tongue. The little knob at the end, marked _a_, bore the horny point of the tongue and directed it; the straight shaft marked _b_ was inside the round part of the tongue as it lay within the bird's mouth; but what was done with these two long branches, fully three quarters of the entire length of the bones? They are too sharply curved to pass down the bird's throat, and, not being jointed, they cannot be doubled back in his mouth. They were tucked away very neatly and curiously. As the hyoid or tongue-bone lies in the mouth its branches diverge just in front of the gullet, and, traveling along the inner sides of the fork of the lower jaw, pass up over the top of the skull, looking in their sheath of muscles like two tiny whipcords. But still the bones are too long by perhaps half an inch for the place they occupy, and the ends must be neatly disposed of. Usually both pass to the right nasal opening and along the hollow of the upper mandible. Very rarely they may curl down around the eyeball in a spiral spring. So when the flicker thrusts out his tongue he feels the pull in the end of his nose, for the tip of the tongue being run out, the long slender bones are drawn out of their hiding-places, down over the skull until they lie flat along the roof of his mouth. As soon as he wishes to shut his bill, back fly the little bones guided by their hollow sheaths of elastic muscle into their hiding-place in the top of the bill. The muscular covering is a part of the same soft envelope that we saw lying in wrinkles at the root of the tongue. It covers the whole length of the little bones just as the woven outside covers an elastic cord.

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.

The red-head is another type. The bill is still nearly of the pick-axe model, the feet not especially different from the flicker's, the tail rather better adapted to life on a tree-trunk, and the tongue entirely unlike the flicker's,--not very extensile and heavily clothed near the tip with long, thick, recurved bristles. We infer that though he may climb well, he is not a drilling woodpecker to any great extent, and that his tongue is adapted neither to extracting borers nor to eating ants from their burrows. His habits bear out the inference. He is arboreal, but his food is either vegetable or picked up from the surface, rasped up rather than speared.

The sapsucker presents still another variation. The points to the tail feathers are more acuminate and the tail itself more resembles that of the tree-dwelling woodpeckers in shape; the feet are fitted for clinging to the trunk; the bill, now perfectly straight and no longer smoothly rounded but buttressed by strong angles that spring from the base and run down toward the tip, is the bill of a woodpecker that lives by drilling; but the tongue is wholly unadapted to catching grubs. What kind of food can an arboreal woodpecker with a drilling bill find upon a tree-trunk when his tongue can be extended only a fifth of an inch, and is furnished with a brush of bristles at the end? We have answered that question before: he eats the inner bark of trees and laps up the sap, for which this brushy tip is excellently fitted. It has been observed that the tongue much resembles the tongues of insect-eating birds, which cannot be extended beyond the end of the bill. It is true that the sapsucker catches great numbers of insects, taking them on the wing like a flycatcher. But he also eats nearly as many ants as the flicker, though their tongues are totally unlike. We have made the mistake perhaps of thinking that ants live only underground and can be obtained only by tongues like those of the flicker and the ant-bear, which hunt them there. But ants are abundant on the surface of the ground, and they excavate long tunnels in rotten wood. The black bear is a famous ant-hunter, yet his tongue is like a dog's and he gets his ants by lapping them up after he has torn open the rotten logs in which they live. This is the way that the sapsucker obtains his ants, and the brush of stiff hairs is a help to him in such work. We see, then, that it is not so much the food as the manner of feeding that explains the form of the tongue.

The downy and the hairy are a step farther along in their development. The fourth toe is longer than the others, a condition that we do not find in any of the woodpeckers not strictly arboreal; the tail is of the improved pattern, holding by a brush of bristles rather than by one stiff point at the end of each feather; the bill is heavier, broader at the base, more heavily ridged, and in every way a stronger tool; and the tongue is highly extensible and of the spear pattern, sharp-pointed and barbed with recurved hooks. Everything about these birds indicates that they are fitted to live on tree-trunks and to dig for borers. This, indeed, is what they do.

But the great logcock and the ivory-billed woodpecker, though of the same type as the other larvae-eating woodpeckers, are more highly developed along the same line. We notice the great strength of the feet; the claws, as large and as sharp as a cat's; the enormous weight and strength of the bill, compared with that of the other woodpeckers, which enables them to cut into the hardest wood and even into frozen green timber; and the great development of the tail, which now becomes a strong spring to support and aid the bird in his work.

As we try to group these particulars under general heads, we see that we have observed three things:--

_That the structure of a bird is adapted to its kind of life._

_That the structure varies by small degrees with the kind of life._

_That the kind of life is conditioned largely upon the kind of food and upon the method of procuring it, more particularly the latter._

These are not so much different truths as three aspects of one truth. When we study the first we see why birds are grouped together into orders and families: we study their resemblances. When we observe the second we see why they are divided into species, for we note their differences. But when we consider the third and reflect that birds have the power to choose new kinds of food or new places and means of getting it, we see how it is that there can come to be new kinds of birds, new subspecies and species, springing up from time to time. Wonderful and improbable as it seems, there is more reason to believe than there is to doubt that new kinds of animals and plants are constantly in process of making; that the laws of change are constantly at work, adapting creatures to their surroundings or crushing them out of existence because they will not learn new ways. And it is probable that these differences which we mark in the woodpeckers have been the result of efforts to adapt themselves to a peculiar kind of life where food was abundant; and also that by acquired habits and by acquired tastes for different kinds of foods they will be subject to still further variations in the future.

XVI

THE ARGUMENT FROM DESIGN

But if the birds are making themselves into new species, where is the place for God in the universe? Did not God make all kinds of creatures in the beginning? How can they go on being made without God?

These are questions every one ought to ask, but--did God leave his world after He had made it and go a long way off? Did He wind it up like a watch to go till it should run down? Is the world a machine, or is it alive?

Long ago the wise and good man Socrates argued that if you did not know there was a God at all, you could at least infer it because everything was so wonderfully made. "There is our body," said he: "every part of it so perfect and so reasonable. Consider how the eyes not only please us with agreeable sensations but are protected in every way. The eyebrows stand like a thicket to keep the perspiration from them, the lids are a curtain to shut out too great light, the lashes screen them from dust,--everything is planned for some wise and reasonable end. And where the evidence of design is so convincing must we not believe that there was a Designer?" Words like these he spoke, and we know because everything is so perfectly contrived that there must have been a contriver, who knew all from the beginning. We are compelled to believe that there is a God.

Shall we believe it less because we find in the creatures about us intelligence and the power to care for their own lives? Has God gone on a visit because these living creatures are looking out for themselves? Were they made less perfectly in the beginning because when new conditions surround them they are able to change to meet the strange requirements? This is not less evidence of a Designer, but more. It was long said that the existence of a watch was proof of a watchmaker who had planned and put together all the parts so that they worked harmoniously. But if the watch had the power to grow small to fit a small pocket, or large to fit a large one, to become luminous by night, and to correct its own time by the sun instead of being regulated by outside interference, what should we have said--that it was proof there was no watchmaker? or that it showed a far more skillful one, since he could make a living, self-regulating, adaptive watch?

And so of the world and the creatures in it. Every evidence we get that they can care for themselves, that they can adapt themselves to new conditions, that they are intelligent and reasonable, capable of improvement in habits or in structure, is so much surer proof that a wise God made them what they are. Evolution--for that is the name by which we call these changes--does not take God out of the universe but makes the need of Him stronger. The argument from design is immensely strengthened when we consider that we have not only an obedient machine acting according to a few fundamental rules, but one that is intelligent also and capable of self-modification.

APPENDIX

_Explanation of Terms._

_a._ Forehead; _b._ crown; _c._ occiput; _d._ nape; _e._ chin; _f._
throat; _g._ jaw-patch, or mustache.

_Occipital_ means "on the occiput."

_Nuchal_ means "on the nape."

_Primaries_ are the nine or ten wing-quills borne upon the last
joint of the wing.

_Secondaries_ are the wing-quills attached to the fore-arm bones.

_Tertiaries_ are the wing-quills springing from the upper arm
bones.

_Wing coverts_ are the shorter lines of feathers overlapping these
long quills.

_Tail coverts_ are the lengthened feathers that overlap the root of
the tail both above and below, called respectively upper and under
tail coverts.

_Ear coverts_ are the feathers that over-lie the ear, often
specially modified or colored.

_Rump_, the space between the middle of the back and the root of
the tail.

[M] is the sign used to indicate the male sex.

[F] is the sign used to indicate the female sex.

A _subspecies_ is a geographical race, modified in size, color, or
proportions chiefly by the influence of climate. These variations
are especially marked in non-migratory birds of wide distribution,
subject, therefore, to climatic extremes. The Downy and the Hairy
Woodpeckers, for example, are split up into numerous races. It
should be remembered that when a species has been separated into
races, or subspecies, all the subspecies are of equal rank, even
though they are differently designated. The one originally
discovered and first described bears the old Latin name which
consisted of two words, while the new ones are designated by triple
Latin names--the old binomial and a new name in addition. The
binomial indicates the form first described. The forms designated
by trinomials may be equally well known, abundant, and widely
distributed. For example, among the woodpeckers, the northern form
of the Hairy Woodpecker was first discovered and bears the name
_Dryobates villosus_; but the first Downy Woodpecker described was
a southern bird, and the northern form was not separated until a
few years ago, so that the southern bird is the type, and the
northern one bears the trinomial, _Dryobates pubescens medianus_.

_North America_, by the decision of the American Ornithologists'
Union, is held to include the continent north of the present
boundary between Mexico and the United States, with Greenland, the
peninsula of Lower California, and the islands adjacent naturally
belonging to the same.

The following key and descriptions will enable the student to
identify any woodpecker known to occur within these limits:

A. KEY TO THE WOODPECKERS OF NORTH AMERICA.

Family characteristics: color always striking, usually in spots, bars, or patches of contrasting colors, especially black and white. Sexes usually unlike; male always with some portion of red or yellow about head, throat, or neck. Tails stiff, rounded, composed of ten fully developed pointed feathers (and two undeveloped feathers). Wings large, rounded, with long, conspicuous secondaries, and short coverts. Bill straight, stout, of medium length. Toes four, arranged in pairs, except in the three-toed genus. Iris brown, except when noted. Marked by a habit of clinging to upright surfaces and digging a deep hole in a tree-trunk for nesting. Eggs always pearly white.

I. Very large--18 inches _or more_; conspicuously crested. A. II. Medium or small--14 inches _or less_; never crested. B.

A. a^1 Bill gleaming _ivory white_; fourth toe decidedly longest.
Ivory-billed Woodpecker. 1.

a^2 Bill _blackish_; fourth toe not decidedly longest.
Pileated Woodpecker or Logcock. 14.

B. a^1 Toes three; [M] with _yellow_ crown.
Three-toed Woodpeckers. 9 & 10.

a^2 Toes four; crown never yellow (b).

b^1 _Not spotted nor streaked either above or below_ (c).

c^1 Body clear black; _head white_.
White-headed Woodpecker. 8.

c^2 Blue-black above; _rump white_; _head_ and _neck red_.
Red-headed Woodpecker. 15.

c^3 Greenish black above, with _pinkish red belly_.
Lewis's Woodpecker. 17.

c^4 Greenish black with _sulphur yellow forehead_ and
_throat._
Californian Woodpecker. 16.

c^5 Glossy blue-black with _scarlet throat_ and _yellow
belly_.
Male of Williamson's Sapsucker. 13.

b^2 _Spotted with black or brown on breast and sides_,
but not streaked nor barred with white (d).

d^1 _Brown_ spots on breast and sides; upper parts plain
brown.
Arizona Woodpecker. 7.

d^2 _Black_ spots on breast and sides; wings and tail
brilliantly colored beneath (e).

e^1 Wings and tail _golden_ beneath; mustaches
_black_ in male, wanting in female.
Flicker. 21.

e^2 Wings and tail _golden_ beneath; mustaches
_red_ in both sexes.
Gilded Flicker. 23.

e^3 Wings and tail _golden red_ beneath; mustaches red.
Red-shafted Flicker. 22.

e^4 Wings and tail _golden red_ beneath; mustaches red;
crown brown.
Guadalupe Flicker. 24.

b^3 _Streaked, spotted, or barred with white on back and wings_ (f).

f^1 _Back streaked_, _plain_, or _varied_, _never_ barred
with white; wings _spotted_ with white (g).

g^1 _Clear_ white and black; _white streak down the
back_ (h).

h^1 Medium size, 9-11 inches.
Hairy Woodpecker. 2.

h^2 Small size, 6-7 inches.
Downy Woodpecker. 3.

g^2 _Grayish_ white and black; _sides closely barred_ (i).

i^1 Back plain black, white _stripe_ down side of throat.
Female of Arctic Three-toed Woodpecker. 9.

i^2 Back with interrupted white stripe, white _line_
down side of throat.
Female of American Three-toed Woodpecker. 10.
(NOTE.--The males are similar with the addition
of the yellow crown. The three toes
cannot ordinarily be seen in life.)

g^3 _Yellowish_ (often dingy or smutty), white and black;
under parts yellowish; back varied with white, no
line nor streak; _rump white_; _white wing-bars_ (j).

j^1 Breast with black patch; head of adult with red
patches.
Yellow-bellied Sapsucker. 11.

j^2 Breast and head red.
Red-breasted Sapsucker. 12.

f^2 _Back barred with white_; wings spotted or barred with
white (k).

k^1 Belly _white; ear coverts white_.
Red-cockaded Woodpecker. 4.

k^2 Belly _white; forehead black_.
Nuttall's Woodpecker. 6.

k^3 Belly _smoky brown_; forehead and breast same.
Texan Woodpecker. 5.

k^4 Belly _sulphur or lemon yellow_.
Female of Williamson's Woodpecker. 13.

k^5 Belly _pinkish red_.
Red-bellied Woodpecker. 18.

k^6 Belly _yellow_, hind neck and forehead orange.
Golden-fronted Woodpecker. 19.

k^7 Belly _yellow_, hind neck brown.
Gila Woodpecker. 20.

B. DESCRIPTIONS OF THE WOODPECKERS OF NORTH AMERICA.

The following are descriptions of all the species of Woodpeckers found in North America, arranged in their proper genera and in the order given in the check list of the American Ornithologists' Union, 1895; with the range of species and subspecies as defined by the same authority or by Bendire's "Life Histories of North American Birds."

1. CAMPEPHILUS PRINCIPALIS, _Ivory-billed Woodpecker_.
Glossy black except _white secondaries_ (very conspicuous) and
white stripe from beneath ear down neck and shoulders; white
nasal tufts; _bill white_. Both sexes crested; [M]
with scarlet occipital crest, [F] with crest
black. Iris yellow. 20 inches.
Cypress swamps of Gulf States, locally distributed.
The largest, shyest, and rarest of our woodpeckers.

2. DRYOBATES VILLOSUS, _Hairy Woodpecker_.
Black and white. Upper parts glossy black with a broad _white
stripe_ down the back; wings thickly spotted with white; under
parts white; three outer pairs of tail feathers white; two white
and two black stripes on sides of head; nasal tufts brownish
white. [M] with scarlet occipital patch. 9-10
inches.
Eastern United States except South Atlantic and Gulf
States, with the following subspecies, all the races being
resident the year round, and breeding in most places
where they are found:--

a. _D. v. leucomelas_, _Northern Hairy Woodpecker_. 10-11 inches.
Larger, whiter.
British America.

b. _D. v. audubonii_, _Southern Hairy Woodpecker_. 8-8.5 inches.
Smaller, more dingy white.
South Atlantic and Gulf States.

c. _D. v. harrisii_, _Harris's Woodpecker_. 9-10 inches.
Upper parts with less white, few wing spots, under parts
soiled white or smoky brown; larger than next.
Northwest coast, northern California to Alaska.

d. _D. v. hyloscopus_, _Cabanis's Woodpecker_. 8.5-9.5 inches.
White stripe down back very wide; purer white below than
_harrisii_; fewer wing spots than _leucomelas_ and _villosus_.
Western United States, except northwest coast, east to
the Rocky Mountains.

e. _D. v. monticola_, _Rocky Mountain Woodpecker_. 10-11 inches.
Larger; more white spots near bend of wing and secondaries
than _hyloscopus_, fewer than _villosus_; pure white below.
Rocky Mountains west to Uintah Mountains, Utah.

3. DRYOBATES PUBESCENS, _Southern Downy Woodpecker_.
Black and white; broad _white stripe_ down back; wings thickly
spotted with white; under parts white. [M] with
scarlet occipital patch. A miniature Hairy Woodpecker, differing
only in having _four_ outer pairs of tail feathers more or less
white and the _outermost barred_. 6.5 inches. Like the Hairy
Woodpecker, the Downy and its subspecies are resident and breed
wherever they occur.
South Atlantic and Gulf States.

a. _D. p. gairdnerii_, _Gairdner's Woodpecker_. 6.75 inches.
Bears same relation to Downy that Harris's does to Hairy
Woodpecker; under parts smoky white; wings spots few.
Pacific coast north to about lat. 55 deg.

b. _D. p. oreoecus_, _Batchelder's Woodpecker_. 7.5 inches.
Under parts pure white; under tail coverts unspotted;
fewer wing spots than _medianus_ and _pubescens_.
Rocky Mountain region of United States.

c. _D. p. medianus_, _Downy Woodpecker_. 7 inches.
The larger, whiter form seen in New England and the
Northern States.

d. _D. p. nelsoni_, _Nelson's Downy Woodpecker_.
Whiter, larger, with fewer black bars on outer tail
feathers.
Alaska and region north of 55 deg.

4. DRYOBATES BOREALIS, _Red-cockaded Woodpecker_.
Upper parts black _barred_ with white, under parts dingy white;
sides streaked and spotted with black; wings spotted with white;
outer tail feathers barred; nasal tufts and _large ear patch
white_; stripe of black down side of neck. [M] with
a tiny tuft of scarlet feathers on each side of head. 7.5-8.5
inches.
Pine woods of southeastern United States, from Tennessee
southwest to eastern Texas and the Indian Territory;
casual north to Pennsylvania.

5. DRYOBATES SCALARIS BAIRDI, _Texan Woodpecker_, _Ladder-backed
Woodpecker_.
Upper parts barred with black and white on back, wings,
and outer tail feathers; sides of head striped; forehead,
nasal feathers, and under parts _smoky gray_, brownest on
belly; _crown speckled with white or red_; [M]
with nape crimson. 7-7.5 inches.
Southern border of United States, Texas to California,
north to southwestern Utah and southern Nevada; generally
resident.

a. _D. s. lucasanus_, _St. Lucas Woodpecker_. Larger.
Lower California, north to 34 deg. in Colorado desert.
These are both subspecies of a Mexican species not occurring
within our limits.

6. DRYOBATES NUTTALLII, _Nuttall's Woodpecker_.
Upper parts barred with black and white; under parts and
_outer tail feathers white_ or dingy white; nasal tufts white;
_forehead and crown black sprinkled with white_. [M]
with red on occiput and nape. 7-7.5 inches.
Southern Oregon and California west of Sierra Nevada
and Cascade Ranges; most common in the oak belt of
the foothills.
Easily distinguished from Downy Woodpecker by being
barred on the back, instead of striped.

7. DRYOBATES ARIZONAE, _Arizona Woodpecker_.
_Upper parts plain brown, not spotted nor streaked_; primaries
dotted with fine white dots; outer tail feathers barred;
under parts white, _thickly spotted_ (except throat), _with large,
round, brown spots_. [M] with red occipital band.
7.5-8.5 inches.
Southern Arizona and southwestern New Mexico; among
oaks of the foothills from 4000 to 7000 feet elevation.

8. XENOPICUS ALBOLARVATUS, _White-headed Woodpecker_.
Glossy black all over, except showy white patch on primaries,
and _head and throat pure white_ (forehead and crown
sometimes grayish). [M] with broad occipital band of
scarlet. 9 inches. "Iris pinkish red" (Bendire).
Mountains of Pacific coast, east to western Nevada and
western Idaho, usually in the pine and fir forests above
4000 feet altitude.

9. PICOIDES ARCTICUS, _Arctic Three-toed Woodpecker_.
_Glossy black above, unmarked_ except by fine white spots on
primaries; under parts grayish white, sides thickly barred
black and white; three outer pairs of tail feathers white,
sides of throat with broad _white stripe_. [M] with
_large crown patch of deep yellow_. 9.5 inches.
British America, south into the northern tier of States
and into the Sierra Nevada Mountains to Lake Tahoe.
Most commonly seen in the track of forest fires, where it
is usually abundant for about two years; rare outside of the
extensive soft wood tracts, and usually found singly or in
pairs except when on burnt land. I have found this species
far more common than the next, and the best mark in life
to be the white _stripe_ on the neck, in distinction from the
white _line_ of _P. americanus_.

10. PICOIDES AMERICANUS, _American Three-toed Woodpecker_.
Very similar to preceding species, but with narrow bars of white
forming an _interrupted stripe down the back_; head thickly
sprinkled with white in both sexes and a white line on nape or
just below; a _white line_, too narrow to be called a stripe,
down side of throat.[M] with _crown bright yellow_.
9 inches. Same range in the East as last; replaced in West by
following subspecies:--

a. _P. a. alascensis_, _Alaskan Three-toed Woodpecker_.
Smaller; more white; nape very white; more white on top
of head.
Alaska, south to 48 deg. (Mt. Baker, Washington).

b. _P. a. dorsalis_, _Alpine Three-toed Woodpecker_.
More white on back and head than _P. americanus_, less than
_alascensis_; but continuous, not barred. "Iris dark cherry-red"
(Mearns).
Rocky Mountain region, south to New Mexico and Arizona.

11. SPHYRAPICUS VARIUS, _Yellow-bellied Sapsucker_.
Under parts whitish or pale sulphur yellow; upper parts black,
mottled with pure or yellowish white; _rump white_; wings
spotted, and with conspicuous white coverts; tail black with
_outer webs of outer feathers_ and _inner webs of middle
feathers light colored_; sides streaked; breast with a _broad
black patch_ extending in a "chin-strap" to the corners of the
mouth; sides of the head striped. Occiput black, nape white.
[M] with forehead, crown, chin, and throat crimson;
[F] usually with crown crimson, forehead black,
and throat white, back more brownish; [F]
sometimes, and young always, with crown blackish. 7.5-8.5
inches.

Colors vary much with age, sex, and season; the wing bar
and yellowish tinge are good marks for all plumages; the
rump and breast patch for adult birds.
Eastern North America, breeding from Massachusetts
northward, migrating in winter to the Southern States.

a. _S. v. nuchalis_, _Red-naped Sapsucker_.
Similar, but an additional red stripe on nape, and the black
chin-strap replaced by crimson. 8-8.5 inches.
Rocky Mountains to Coast Range, replacing the above in
the mountains; usually breeding at from 5000 to 10,000
feet elevation.

12. SPHYRAPICUS RUBER, _Red-breasted Sapsucker_.
Body and under parts similar to _S. varius_, but back much
less variegated with white. No black on breast, no white
stripe through eyes. Nasal tufts brownish instead of white.
_Head_, _neck_, and _breast uniform crimson_. _Sexes alike._ Young
with crimson replaced by gray or "claret brown" (Bendire).
8.5-9 inches.
Pacific coast, Sierra Nevada, and on both sides of Cascade
Mountains; a summer resident only north of northern
California.
At first sight the Red-breasted Sapsucker might be mistaken
for the Red-headed Woodpecker, but the two birds
do not inhabit the same country.

13. SPHYRAPICUS THYROIDEUS, _Williamson's Sapsucker_.

Sexes totally dissimilar except in having a white rump and
yellow under parts. _Male, glossy black all over except_
conspicuous _white rump_ and _white wing coverts_, two white
stripes on sides of head, white nasal tufts, white spots on
primaries; sides and tail coverts mottled; a stripe of scarlet
down middle of throat and _brilliant yellow under parts_.
_Female, light brown_; head clear brown; body, wings, and tail
closely _barred_ with black and white; no white wing coverts;
rarely a red throat like male; usually but not always a large
black patch on breast, and always a _yellow belly_ and _white
rump_. Young males lack the red on the throat and usually the
yellow on the belly; the black is dull, and the throat a dingy
white. Young females lack the yellow on the belly and the black
on breast, and are dull-colored and indistinctly marked. 9-9.5
inches.

Rocky Mountain region, west to Sierra Nevada, Cascades
and northern Coast Ranges, breeding at from 5000
to 9000 feet elevation. The handsomest of our woodpeckers.

14. CEOPHLOEUS PILEATUS, _Pileated Woodpecker, Logcock_.
Body blackish slate; wings with a large white patch conspicuous
only when flying; throat white; a white stripe
across cheek and down neck; jaw-stripe scarlet in male,
blackish in female; both sexes with scarlet crest, but in the
male the whole top of head (which is slaty black in female)
equally brilliant. This red cap gives the bird the name of
_pileated_. Iris yellow. 17 inches.
Wooded regions of Southern States, Florida to North
Carolina, very rarely near settlements, but far more common
than the following subspecies of the North and
West.

a. _C. p. abieticola_, _Northern Pileated Woodpecker_.
Larger; more extensive white markings; the black grayer
or browner.
From Virginia northward to 63 deg. in the East, and in the
West among the Rocky Mountains, north of Colorado, to
the northwest coast; a shy woodland bird to be looked
for only in the primitive evergreen forests, though sometimes
occurring in any heavy timber and, in New England,
upon the higher well-wooded mountains. The
largest of the northern woodpeckers; resident.

15. _Melanerpes erythrocephalus_, _Red-headed Woodpecker_.
Wings, tail, and upper parts glossy blue-black; rump, exposed
secondaries, and under parts from breast downward
pure white; _head_, _neck_, and _breast crimson._ _Sexes alike._
Young with red and black wholly or partly replaced by
grayish brown; can be recognized by white markings. 9.5
inches.
United States, west to Rocky Mountains; rare east of
Hudson River, but ordinarily breeding wherever found;
in winter usually migratory from its northern limits, the
migration depending principally upon the food supply
and depth of snow.

16. MELANERPES FORMICIVORUS, _Ant-eating Woodpecker_.
Upper parts, wings, and tail glossy greenish black; _rump_
and lower parts _white_; white patch on primaries, conspicuous
in flight; upper throat and line about the bill dull
black; _forehead_ with _wide white band_; lower _throat sulphur
yellow_; breast and sides thickly streaked with black and
white. [M] with crown and occiput crimson;
[F] with crown black, occiput crimson.
Iris white. 7-9 inches.
Mexico; western Texas.

a. _M. f. angustifrons_, _Narrow-fronted Woodpecker_.
Similar, but with a _narrow band of white_ across the _forehead_;
breast and sides not so thickly streaked.
Lower California, never occurring within the borders of
the United States.

b. _M. f. bairdi_, _Californian Woodpecker_, _El Carpintero_.
Similar to _M. formicivorus_, but the breast black, little
streaked with white except along the sides; yellow of throat
paler, or replaced by white. Iris white. Larger, 7.5-9.5
inches.
Pacific coast, north into Oregon to 44 deg., east to southern
New Mexico and Texas in the south and to the eastern
slopes of the Sierra Nevada and Cascade Mountains in
the north, but more abundant, on the western than on the
eastern slopes of these mountains.

17. MELANERPES TORQUATUS, _Lewis's Woodpecker_.
Upper parts, wings, and tail glossy greenish black; under
parts _pinkish red_; chest and _collar round hind neck hoary
gray_; crown and sides of head black; forehead, cheeks, and
chin crimson. _Sexes alike._ Young with pink replaced by
grayish. 10.5-11.5 inches.
Pacific coast, east to Black Hills and Rocky Mountains
between Arizona and 49th parallel; casual still farther
east; migratory in its northern ranges; a silent, heavy
flying bird, different in habits and appearance from the
other woodpeckers; often seen flycatching.

18. MELANERPES CAROLINUS, _Red-bellied Woodpecker_, _Zebra Bird_.
Back and wings black, _barred with white_; under and upper
tail coverts, middle and outer tail feathers, white varied with
black; head and under parts ashy; _belly tinged with reddish_.
[M] with whole top of head and nape bright red;
[F] with forehead and nape red, crown gray. 9-10
inches.
Eastern and Southern States between the Hudson River
and the Rocky Mountains, north to southern New York,
Ohio, southern Michigan, etc.; migratory in its northern
ranges.

19. MELANERPES AURIFRONS, _Golden-fronted Woodpecker_.
Back and wings barred with black and white; rump white; entire
under parts brownish white, unspotted (except under tail
coverts); primaries unspotted, except at tip; tail black with
slightly barred outer feathers; _belly yellowish; forehead and
hind neck orange in both sexes_. [M] with _crown
red_ set in a larger patch of clear gray; [F]
with crown clear gray. 9.5 inches.
Central and southern Texas, north to about 33 deg.; breeds
wherever found.

20. MELANERPES UROPYGIALIS, _Gila Woodpecker_.
Back and wings barred with black and white; _head and
lower parts smoky brown_; rump black and white; tail barred
on inner and outer feathers; primaries unspotted; belly yellow
(not conspicuous). [M] with red crown surrounded by
brownish; "iris red" (Hayden). 9 inches.
Southwestern New Mexico and Arizona to southeastern
California, usually above 2000 feet altitude; its distribution
depending principally upon the giant cactus.

21. COLAPTES AURATUS, _Flicker_, _Yellow-hammer_, _High-hole_,
_Clape_.
Back and wings (except primaries) brownish gray, barred with
black; under parts pale vinaceous spotted with black spots from
breast downward; _rump white; tail and wings golden yellow
beneath_, dark above, showing the yellow shafts; tail feathers
with black tips below; top of head ashy gray, sides of head and
throat vinaceous; a broad _black crescent_ across breast, a
bright scarlet one on nape. [M] _with black jaw
patches_; [F] without them. 12 inches.
South Atlantic and Gulf region, north to North Carolina.

a. _C. a. luteus_, _Northern Flicker_.
Larger; paler; black bars above narrower; less black and
white below.
North from North Carolina and west to the Rocky Mountains;
casual farther west; migratory from its northern
ranges.

22. COLAPTES CAFER, _Red-shafted Flicker_.
Color pattern similar to above with the following differences:
_wings and tail red beneath_ instead of yellow; throat ashy
gray; usually no red on occiput (though some specimens show a
narrow crescent). [M] _with red jaw patches_.
12.5-14 inches.
Rocky Mountain region west to Pacific coast from
Mexico to British Columbia, except northwest coast
region of Oregon, Washington, and British Columbia,
and occasionally east to Kansas and Nebraska; resident
except in the more northern portions of its range.

a. _C. c. saturatior_, _Northwestern Flicker_.
Darker; smaller; narrower breast crescent.
Northwest coast, replacing the above, from which it cannot
be separated in life.

23. COLAPTES CHRYSOIDES, _Gilded Flicker_; _Cactus Flicker_.
Color pattern same as _C. auratus_, but throat gray; top of head
brown; _occiput without band_; tail band broader and yellow
paler than in _C. auratus_. [M] with _jaw patches
bright red_; "iris blood red" (Hayden).
Central and southern Arizona and Lower California.

a. _C. c. brunescens_, _Brown Flicker_.
A curious subspecies of the last, smaller, with larger,
more numerous spots and a smoky brown cast of plumage;
black tail band very wide; jaw patches red; wings and tail
yellow beneath.
Lower (not southern) California; casual only in southern
California; in Arizona to 35 deg.

24. COLAPTES RUFIPILEUS, _Guadalupe Island Flicker_.
Coloration like _C. cafer_, crown decidedly brown; crescent
on nape wanting; jaw patches red; wings and tail _red_ beneath.
Guadalupe Island off the coast of Lower California.

INDEX

Aard-vark, 104.

Acorns, eaten by woodpeckers, 46, 51, 57, 58, 59.

Acquired habits, 61-66.

Adaptations of woodpeckers to environment,104-109.

Ant-bear, 104, 106.

Ants, as food for woodpeckers, 3, 30, 63, 105, 106.

Argument from design, 110.

Bear, black, 107.

Beechnuts, as food for woodpeckers, 57, 58, 59.

Beetles, as food for woodpeckers, 3, 11, 63.

Bill of woodpeckers as a tool, 68-76.

Borers, 3, 10, 11, 29, 30, 36.

Burroughs, John, quoted, 17.

Cacti, woodpeckers nesting in, 20.

Cannibalism among woodpeckers, 64.

Carpenter, the. _See_ California woodpecker.

Carpintero, El. _See_ California woodpecker.

Caterpillars, as food for woodpeckers, 10, 11, 29, 63.

Cecropia chrysalids, eaten by woodpeckers, 9.

Chestnuts, eaten by woodpeckers, 59.

Chickadee, 16, 21, 25, 30, 32, 74.

Chipmunks, hoarding food, 60.

Clape. _See_ Flicker.

Creeper, brown, 5, 81, 87, 88.

Crossbills, eating salted food, 31.

Crow, hoarding habit, 60; 74.

Cuckoo, ground, 82.

Cuckoos, yoke-toed, 5, 82.

Drumming of yellow-bellied sapsucker, 16, 17.

Evolution, 109, 112.

Feeding young, how the flicker does it, 24, 25.

Fence-posts used by woodpeckers, 48, 56, 58.

Finch, purple, 39.

Finches, 74.

Fish-spears, 12, 13.

Flicker, 6, 7, 15, 18, 20, 23-26, 73, 74, 82, 88, 89, 95, 97-99,
101, 103, 106, 125.
brown, 126.
cactus, 126.
gilded, 126.
Guadalupe Island, 127.
northern, 126.
northwestern, 126.
red-shafted, 126.

Flycatching habits of woodpeckers, 7, 56, 106, 124.