N. Mex., accompanied by a small English terrier. In front
of my tent stood a large dead pine, near the top of which
there were a number of holes, evidently the homes of four
pairs of Ant-eating Woodpeckers (_Balanosphyra formicivora
aculeata_). A gray tassel-eared squirrel came scampering
along, and was at once spied by the dog, which gave chase.
The squirrel ran up the dead tree mentioned above, to be
instantly assailed by the woodpeckers. Their constant cries
and their sharp bills made things so uncomfortable for the
squirrel that it ran down the tree to within a few feet of
the dog, who sent him scampering to the top again with his
eight antagonists constantly flaying him.
About this time there was a swish of wings, and a
sharp-shinned hawk (_Accipiter velow_) darted like a streak
among the woodpeckers. For an instant it seemed that one
of them was doomed, but by a small margin it managed to
escape, and in an instant they had all darted to cover
among the green boughs of surrounding trees. All was quiet
for a few brief seconds, when the woodpeckers returned to
the attack, except one which perched on the topmost bough
of a near-by tree, as guard or lookout, watching for the
hawk. The other seven took up the fight with the squirrel.
In a few minutes the hawk again appeared on the scene,
the guard gave a shrill call of warning, and all the
woodpeckers were under cover before their enemy could reach
them. The hawk, then, finding the birds on their guard,
left and did not return. The terrier soon abandoned the
tree, and the squirrel hurried down and scampered away; the
woodpeckers quickly quieted down and went peacefully about
their home affairs. I believe that the birds recognized in
the squirrel a danger to their eggs or young.
BALANOSPHYRA FORMICIVORA MARTIRENSIS Grinnell and Swarth
SAN PEDRO WOODPECKER
HABITS
The acorn-storing woodpecker of the Sierra San Pedro Martir,
northwestern Baja California, has been separated and described by
Grinnell and Swarth (1926) under the above name, to which they have
added the long common name “San Pedro Martir acorn-storing woodpecker.”
Its distinguishing characters are given as follows:
Most nearly like _B. f. bairdi_. Distinguished from that
species primarily by shorter wing, and by slightly shorter
and notably weaker, more slender bill; also by average
differences in head markings as set forth below. * * *
The relatively feeble bill of this bird, as compared
with that of the upper California _bairdi_, is the most
conspicuous character of this subspecies. In bill structure
it is closely similar to _B. f. aculeata_, of Arizona.
The character of the head markings in the female is
suggestive again of _aculeata_, the red area being usually
more nearly square, as in that form, rather than shorter
than wide, as in _bairdi_. The white frontal band averages
slightly narrower than in _bairdi_, an approach toward the
condition in _angustifrons_, of the Cape San Lucas region.
The yellowish white (more dilutely yellow than in _bairdi_)
U-mark on the lower throat in both sexes averages very much
narrower in our specimens of _martirensis_ than in a large
series of _bairdi_ usually only about half the width of the
former as in the latter. This we are not quite confident of
as a real character, in that there is a chance that “make”
of specimen (whether or not the skin of the throat was
stretched) affects the width of the white band. * * *
In character of the markings on the feathers of the breast
there is no departure from the condition in _bairdi_. The
upper breast is broadly and solidly black, the black band
not penetrated posteriorly with white streaks to such an
extent as in _aculeata_ and _angustifrons_.
The range is given as, “so far as now known, only parts of the Sierra
San Pedro Martir, in northern Lower California, between latitudes
30° and 31°30″; altitude 5,800 to 7,200 feet; life-zone mainly Upper
Sonoran (live-oak association), but also Transition locally or
sporadically.”
The eggs are similar to those of other races of the species. The
measurements of 12 eggs average 26.19 by 18.35 millimeters; the eggs
showing the four extremes measure =25.1= by =19.4=, =19.0= by 18.5, and
22.8 by =16.8= millimeters.
ASYNDESMUS LEWIS (Gray)
LEWIS’S WOODPECKER
PLATE 29
HABITS
My first impression of this curious and interesting woodpecker was of
a large, black bird that looked more like a crow than a woodpecker and
that flew with the strong, steady flight of a crow or a jay, with
none of the undulations common to so many woodpeckers. I made the same
comment the second time I saw it, and am interested to see that the
same impressions were made on many others.
It is essentially a bird of the more open country and among scattered
large trees, rather than of the heavily forested regions. S. F. Rathbun
writes to me of its haunts in western Washington: “In this section of
the State are many tracts of land commonly known as ‘old burns.’ At
one time all were forested, then later they were swept by fire and in
some instances more than once; but even now, on many, still stand the
scarred and blackened trunks of what formerly were large, tall trees;
and it is in or about these unattractive places that this woodpecker is
more apt to be found, although by no means is it restricted to them.”
Major Bendire (1895) says: “I have rarely seen Lewis’s woodpecker in
deep forests; far more frequently just on the outskirts of the pines,
in juniper groves on the table-lands bordering the pines, as well as in
the deciduous timber along streams in the lowlands, and occasionally
even in solitary cottonwoods or willows, near some little spring, in
the drier sagebrush-covered flats, miles away from the nearest forest.”
Winton and Donald Weydemeyer (1928) say that in northwestern Montana it
is--
a common summer resident throughout most of the Transition
zone. It occurs most regularly in mixed broadleaf and
conifer woods in river valleys, and in open forests of
yellow pine along the foothills. It rarely ranges into the
higher mountains, although we observed one individual in a
Canadian zone forest of lodgepole pine and alpine fir, at
an altitude of 6,160 feet. In cut-over or burned woods, it
ranges to a higher elevation than in virgin forests.
In the eastern part of the county, this woodpecker is most
common around farms and slashings, and in the more open
woods of fir, larch, and yellow pine. Near Libby, in the
western part, it seems to prefer creek-bottom woods of
aspen, spruce, and cottonwood.
Johnson A. Neff (1928) says that his “acquaintance with this exotically
brilliant woodpecker began in the mountains of Colorado, and even
now the thought of it calls to mind that bleak, wind-blown area at
an elevation of 8,500 feet, where these birds were very much at home
in the dead trunks of spruce and hemlock that had once covered the
mountains with living verdure.”
_Nesting._--Mr. Rathbun says in his notes: “In western Washington this
woodpecker nests in June. Almost invariably the excavation for its
nesting place is in a dead tree, the trunk of which is more or less
blackened by fire, and this may be one reason why the bird is partial
to the old burns. The tree may be one of several scattered about, or,
infrequently, somewhat isolated. But in any event, this woodpecker
shows a liking for a good-sized tree, broken off at quite a height, the
outside of which has been charred or blackened by the flames. We have
found many of its nesting places, and among these was one we shall not
forget. In this case, the tree was a very large one, was broken off at
a height of about 175 feet, and, as usual, had its outer surface burnt.
Not far below its top was the entrance to the nest of a pair of these
woodpeckers. Because it was so high it could be distinctly seen only by
the use of glasses, but often we had noticed one of the birds enter it
or come out of it. This nesting place was used for a number of years,
and when it was in use we have gone out of our way more than once just
to see these woodpeckers; for the top of the tree was used as a lookout
station by the pair of birds, from which at times one or both would
sail into the air after a flying insect.”
Major Bendire (1895) says that--
it is by no means as particular in the choice of a nesting
site as the majority of our Woodpeckers. Shortly after
arriving on their breeding grounds a suitable site is
selected for the nest, and not infrequently the same
excavation is used for successive years. In most cases
the nesting sites are excavated either in the tops of
tall pines or in dry cottonwoods, and in tall rotten tree
trunks, occasionally in partly decayed limbs of sycamores,
oaks, and less frequently in junipers and willows. The
nests, as a rule, are not easily gotten at, and quite a
number are practically inaccessible, varying in height from
6 to fully 100 feet from the ground.
* * * [At Camp Harney, Oreg.] these birds nested mostly in
junipers. * * * The junipers which are selected for nesting
sites were invariably decayed inside, and after the birds
had chiseled through the live wood, which was usually
only from 1 to 2 inches thick, the remainder of the work
was comparatively easy; the same site, if not disturbed,
was occupied for several seasons, and in such the inner
cavity was much deeper, some being fully 30 inches deep and
generally about 4 inches wide at the bottom. The entrance
hole varies from 2 to 2½ inches in diameter, and when this
is made by the birds it is always perfectly circular; but
occasionally a pair will take advantage of an old knot
hole, if it and the cavity it leads to are not too large.
The Weydemeyers (1928) say that in northwestern Montana this species
exercises a wide range of selection for nesting trees; of four nests
that they record, two were in larch stubs, one in a dead cottonwood,
and one in a live yellow pine; these nests were in the Transition Zone
at elevations between 2,000 and 3,100 feet.
Ed. S. Currier (1928) found Lewis’s woodpeckers nesting in what
he called “colonies,” near Portland, Oreg.; in each of two dead
cottonwoods, less than a mile apart, he found three occupied nests all
on the same day.
_Eggs._--Bendire (1895) says:
From five to nine eggs are laid to a set; those of six or
seven are the most common, but sets of eight are not very
rare; I have found several of that number, and a single set
of nine.
The eggs of Lewis’s woodpecker vary greatly in shape and
also in size. They are mostly ovate or short ovate in
shape, but an occasional set is decidedly rounded ovate,
while others are elliptical ovate; the shell is close
grained and, in most cases, dull, opaque white, without
any gloss whatever. Some sets, however, are moderately
glossy, but scarcely as much so as the better-known eggs of
the red-headed woodpecker, and none are as lustrous as the
eggs of the flicker.
The measurements of 58 eggs average 26.22 by 19.99 millimeters; the
eggs showing the four extremes measure =30.48= by 21.34, 26.67 by
=24.38=, and =23.37= by =17.27= millimeters.
_Young._--Major Bendire (1895) says of the young:
Both sexes assist in incubation, and this lasts about two
weeks. The young leave the nest about three weeks after
they are hatched, and are readily tamed. I kept a couple
for several days, but they had such enormous appetites that
I was glad to give them their liberty, as they kept me
busy providing suitable food. They were especially fond of
grasshoppers, but also ate raw meat, and climbed everywhere
over the rough walls of my house. A considerable share of
the food of these birds is picked up off the ground, and
they appear to be much more at home there than woodpeckers
generally are. The young are fed on insects, and I believe
also on berries; I have seen one of these birds alight
in a wild strawberry patch, pick up something, evidently
a strawberry, fly to a tree close by in which the nest
was situated, and give it to one of the young which was
clinging to the side of the tree close to the nesting site.
_Plumages._--The young Lewis’s woodpecker is hatched naked and blind,
but the juvenal plumage is acquired before the young bird leaves
the nest. In fresh juvenal plumage the red “face” of the adult is
replaced by black or dusky, though a young bird taken on July 22
shows some red mixed with the black in this area; the bill is small
and weak; the crown and occiput are dull brownish black, without any
greenish luster; the silvery-gray nuchal collar of the adult is wholly
lacking; the under parts are mostly dull pale gray or dull grayish
white, more or less suffused on the central breast and abdomen with
dull red or orange-red; the whole plumage is softer and more blended
in texture. Dr. J. A. Allen (Scott, 1886) says of some young birds
that he examined: “The back and upper surface of the wings are bronzy
green nearly as in the adult, with, however, in addition, broad bars
of steel-blue on the scapulars and quills. These bars are especially
prominent on the secondaries and inner vanes of the primaries, and are
seen also in some specimens on the rectrices. The steel-blue edging the
outer vanes of the quill feathers in the adult is absent; and the inner
secondaries and longest primaries are tipped more or less prominently
with white.”
This juvenal plumage is worn through the summer and into September,
when the molt into the first winter plumage begins with a sprinkling
of the silvery, bristly feathers appearing on the breast and in the
collar, with the increase of red in the “face,” and with metallic-green
feathers showing on the head. This molt is apparently prolonged and is
not finished until early in winter, when young birds and adults are
practically alike. Adults have a complete annual molt late in summer
and fall; I have observed it as late as October 12.
_Food._--Referring to the food of Lewis’s woodpecker, Major Bendire
(1895) writes:
In summer its food consists mainly of insects of different
kinds, such as grasshoppers, large black crickets, ants,
beetles, flies, larvæ of different kinds, as well as of
berries, like wild strawberries and raspberries, service
berries and salmon berries, acorns, pine seeds, and juniper
berries, while in cultivated districts cherries and other
small fruits enter into its daily bill of fare. Here, when
common, it may occasionally do some little damage in the
orchards, but this is fully compensated by the noxious
insects it destroys at the same time. In localities where
grasshoppers are abundant they live on these pests almost
exclusively while they last. Mr. Shelly W. Denton tells
me he noticed this Woodpecker gathering numbers of May
flies (_Ephemera_) and sticking them in crevices of pines,
generally in trees in which it nested, evidently putting
them away for future use, as they lasted but a few days. It
is an expert flycatcher, and has an extremely keen vision,
sallying forth frequently after some small insect when this
is perhaps fully 100 feet from its perch.
On this latter subject, Mr. Rathbun writes to me:
Lewis’s woodpecker is an expert at catching insects on the
wing. When in this act, its perch is some vantage spot,
such as the top of a dead tree or a bare limb in the open.
Here it sits motionless, except to turn its head from side
to side on the lookout for its prey; and when this is seen,
the bird glides from its resting place to make a capture.
On one occasion for more than an hour, we watched a pair of
these woodpeckers seize flying insects, and in that length
of time not less than 35 were taken. Through our field
glasses we kept a close watch on the birds and soon learned
from their actions when an insect was sighted, thus it was
easy for us to anticipate its capture, and in not a single
instance was a failure made by either of the birds. Once,
a light puff of air changed the course of the insect just
at the time it was about to be taken, but the woodpecker
made a quick turn upward at the same time, dropped its legs
straight down, and neatly made the take. When busy catching
insects on the wing, this bird leaves its perch by easy
wing beats or a long, slow, graceful glide; then, after its
prey is caught, rises in its flight and, quickly wheeling,
returns to its lookout station.
But, as if not content with hunting insects after the
manner of a flycatcher, sometimes this bird mingles with
the swallows as they hawk over the ground. On one occasion
in summer, as we came to a very open pasture, we noticed
numbers of barn and cliff swallows in flight over it after
insects, and in company with them was a pair of Lewis’s
woodpeckers. Back and forth over the meadow flew these
dark birds, busy in an attempt to catch flying insects,
and their actions as they flew were in marked contrast to
those of the graceful swallows. Although we watched the
woodpeckers for more than half an hour, throughout that
time neither one alighted; and when we left the place both
still coursed busily above the field.
About one-third of the food of Lewis’s woodpecker consists of acorns.
It shares with the California woodpecker the interesting habit of
storing acorns, though its method of storing them is quite different,
for it seldom, if ever, makes the neat round holes to fit the acorns,
so characteristic of the other species; and its stores of acorns are
never so extensive, so systematic, or so conspicuous as those of the
California woodpecker. Charles W. Michael (1926) writes:
Recently we watched a Lewis Woodpecker making trips back
and forth between a Kellogg oak and his home tree, a
cottonwood. He was busy storing away his winter supply of
acorns. Occasionally he picked a fallen acorn from the
ground; more often he flew into the lesser branches of the
oak, and hanging like a great black chickadee he plucked
the acorn from the cup. With crow-like flappings, his broad
wings carried him back to the dead cottonwood with his
prize in his bill. Alighting somewhat below the summit of
his tree he would, by a series of flight jumps, come to a
certain shattered stub where a fissure formed a vise. Into
this he would wedge the acorn.
With the acorn held firmly in place he would set about
cutting away the hull, and strong strokes of his bill would
soon split away the shell and expose the kernel. But he was
not satisfied in merely making the kernel accessible, he
must go on with his pounding until he had broken it into
several pieces, and then with a piece in his bill he would
dive into the air like a gymnast, drop twenty or thirty
feet and come with an upward swoop to perch on the trunk
of the same tree. A few hitching movements would bring him
to a deep crack that opened into the heart of the tree.
Here he would carefully poke away, for future reference,
his morsel. Usually the acorn was cut into four parts,
involving four such trips, and on the last trip to the vise
he would take the empty hull in his bill, and with a jerk
of his head, toss it into the air. An examination of the
ground beneath the tree disclosed hundreds of empty acorn
shells. Holding a watch on the Lewis Woodpecker, we found
that he made five trips in five minutes and stored five
acorns.
J. Eugene Law (1929) has published another illuminating paper on this
subject, which is well worth reading; he describes in considerable
detail the woodpeckers’ methods in storing the meats of acorns in
cracks in poles and indulges in some speculation as to the causes and
purposes involved in the habit.
Herbert Brown (1902) found Lewis’s woodpeckers quite destructive to
pomegranates and quinces, near Tucson, Ariz. On September 30 he counted
ten in the pomegranate groves; “they were mostly feeding on pomegranate
fruit. They first cut a hole through the hard skin of the fruit and
then extract the pulp, leaving nothing but an empty shell.” Later, on
October 13, he says: “Now that the pomegranate crop has been destroyed
they have commenced to eat the quinces, of which there are large
quantities. On the tops of some of the bushes I noticed that every
quince had been eaten into, one side of the fruit being generally eaten
away.”
William E. Sherwood (1927) writes:
On June 16, 1923, while collecting near Imnaha, Wallowa
County, Oregon, I frightened a Lewis woodpecker from the
top of a fence post where it was evidently having a feast.
On top of the post it had left a fresh egg, probably its
own; for it was absolutely fresh, of the right size, and
unmarked. The shell had been broken into, but the contents
not yet extracted.
In a knothole on the side of the post was an eggshell (of
the same kind), and a snail shell which had been broken
into. Wedged into the cracks of the post were several
insects (some of them still alive) of the two species
commonly known as “salmon flies” and “trout flies.” On the
ground at the foot of the post were several snail shells,
a green prune (picked into), and several cherry seeds with
stems attached.
Johnson A. Neff (1928) has much to say about the economic status of
this woodpecker, mainly in Oregon. A few quotations from his paper will
serve to show the vast amount of damage to the fruit grower that it
does in sections where it is abundant, mainly in summer and fall. He
says that Prof. Beal (1911) “mentions one case in Washington wherein
the birds tore the paper at the corners of packed boxes of apples left
in the orchard over night, picking into every apple within reach, and
necessitating the repacking of every box attacked.”
S. D. Hill wrote to Mr. Neff:
In some sections and seasons they will destroy carloads of
fruit, especially in orchards near timber. I have known
them to do 50 percent damage to a pear crop in the Peyton
district on upper Rogue River. Jackson Gyger, Ashland,
wrote: “In 1924 the loss on Spitz and Delicious apples was
about 75 percent, on Newtowns about 15 percent; Bosc and
Anjou pears about 10 percent. The loss on trees near oak
timber was nearly 100 percent. This season (1925) due to
hunting them every day the loss was possibly 50 percent
less. I bought $18.00 worth of ammunition to combat them
this year. One man can not keep them out of a seven acre
orchard, as they will work on one end while you are scaring
them out of the other.”
Mr. Neff goes on to say:
These complaints can not be over-looked, for stomach
analyses show only the volume of fruit eaten, not the
percentage of fruit damaged per tree, nor the real loss to
the orchardist. * * *
In Oregon, although it sometimes becomes a nuisance in the
small fruit plantings of various areas, it centers its
destructive activities in the Rogue Valley; there it flocks
in the greatest abundance. * * *
In this area there can be no question of the objectionable
status of the Lewis woodpecker. If the birds would consume
each fruit injured, there would be little complaint of
their taking the quantity which probably would satisfy
them. They are restless and energetic, however, and always
attacking fresh fruit, which with one stroke of the bill
is ruined for commercial use. If one allows only one bite
to each fruit, some of the stomachs studied would have
contained the samples of as high as two bushels of fruit.
In the restricted areas mentioned the Lewis woodpecker is a
pest.
_Behavior._--Lewis’s woodpecker seldom indulges in the undulating
flight so common to other woodpeckers, though it sometimes swings in a
long curve in a short flight from tree to tree. Its ordinary, traveling
flight is quite unlike the flight of other members of the family; it is
strong, direct, and rather slow, with steady strokes of its long, broad
wings. At first glance one would hardly recognize it as a woodpecker,
for its flight and its appearance are more suggestive of a crow, a
Clarke’s nutcracker, or a jay. But it is far from clumsy in the air,
and its skill in catching insects on the wing demonstrates is mastery
of the air in flight. It also indulges in some rather remarkable
aerial evolutions, which one would hardly expect from a member of the
woodpecker family. On this subject, Robert Ridgway (1877) writes: