THE BIRDS
NORTHERN PILEATED WOODPECKER. Phloeotomus pileatus abieticola
(Bangs)
Field characters.Much
the largest of our woodpeckers (length over 17 inches). Body plumage
black; a brilliant red crest on head (fig. 46); a large white area on
forward part of under surface of wing; a smaller spot of white on middle
of outer surface of wing. Flies usually in direct course, sometimes in
great undulations, with rather slow and regular wing beats.
Voice: A loud but low-pitched note, kuk, uttered a varying
number of times in rather slow and irregular succession.
Occurrence.Common
resident in Transition Zone and lower part of Canadian Zone on west
slope of Sierra Nevada. Observed near Feliciana Mountain and 6 miles
east of Coulterville, and thence eastward to Mono Meadow (7300 feet
altitude), and to Little Yosemite Valley at 6200 feet. Seen in Yosemite
Valley at all seasons of the year. Lives chiefly in white fir
woods.
The Northern Pileated Woodpecker has been aptly
called Cock-of-the-woods, for it is by far the largest woodpecker within
our region. It is exceeded in size and in loudness of voice by but few
of all the forest birds. In general, the range of this species closely
duplicates that of the fir trees, in recognition of which fact, it was
called abieticola (fir-inhabiting). In the Yosemite region the
bird is found chiefly in the belt of forest characterized by the
presence of the white fir (Abies concolor).
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Fig. 46. Head of Northern Pileated Wood
pecker showing stout ridged bill, "mask" to keep dust from rotten wood
out of nostrils, prominent crest, and slender neck. One-half natural
size.
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The pileated woodpecker is conspicuous either in
flight or when perched. When a bird is at rest or working on the side of
a dead stub, its brilliant red crest can generally be seen plainly. In
the female the forehead is blackish, while in the male the red covers
the whole top of the head, forward to the bill. The latter sex has, in
addition, a narrow red streak extending backward from the side of the
bill along each cheek. The neck of this woodpecker is much longer and
relatively more slender than that of other species, and this impression
of slenderness is enhanced by the streak of white which extends down
each side from the cheek to the side of the body; otherwise the plumage
of the resting bird appears solidly black. When it takes to flight a
large white area shows forth, intermittently, on the forward part of the
under surface of the spread wing, and on the adjacent side of the body;
a smaller patch of white is to be seen as well on the middle of the
upper surface of the wing.
The call or alarm note of the pileated woodpecker is
a single-syllabled, low-pitched but loud kuk, kuk, kuk, etc.,
uttered in series, at intervals of a half-second or more, depending upon
whether the bird is in flight or perched. Sometimes, when a bird is
pursuing a long direct course, its notes will be heard from the time it
first comes into view until it passes out of hearing in the opposite
direction. The call resembles one of the notes of the Red-shafted
Flicker, although it is not so high-pitched.
This bird's flight is quite different from that of
our other woodpeckers. It ordinarily pursues a direct course, with wings
beating continuously though slowly, in a manner resembling the
monoplane-like flight of a magpie. Its head meanwhile is drawn in,
somewhat after the manner of a heron.
While one of our party was traversing the Glacier
Point road near Mono Meadow on the morning of June 13, 1915, he heard a
loud pounding which he at first thought might be the noise made by a
lineman in repairing the broken-down telephone wire along the road. The
racket was followed upand the observer came upon a pileated
woodpecker foraging on a white fir stub. The bird delivered 3 to 8
vigorous blows in rather slow succession, and repeated the series about
4 times a minute. The bird would draw its head far back, so as to move
it through an arc fully 8 inches in length, and the combination of long
neck, heavy head, and stout sharp bill (fig. 46) made for results. With
every few series of strokes a large flake of dead bark would fall to the
ground with a clatter. Other birds, working with similar industry, have
been seen to throw chips fully 2 feet backward as they chiseled off the
dead wood.
Another pileated woodpecker was observed working
diligently on a dead yellow pine in Yosemite Valley on December 24,
1914. After every few taps the bird would stop and look about intently,
thus bearing out the impression of its wariness we had gained elsewhere.
It rapidly gouged away the dead pine wood, in long splinters, and often
used its strong bill as a pry to give the final loosening touch to a
particularly large chunk around which it had chiseled. The noise made,
as the bird delivered a blow with all the force in its long neck and
powerful body, was as loud as that made by a carpenter when hitting a
nail. When two birds are working in the same vicinity the resulting
noise is considerable. A pair drilling near Yosemite Point on June 4,
1915, produced tones about an octave apart, evidently due to differences
in the wood upon which they were working.
The total amount of excavation done by these birds is
surprising. Many dead fir stubs seen near Aspen Valley were literally
riddled with surface cavities, some of which were large enough to admit
a man's fist. Sometimes great vertical troughs had been dug in the sides
of these dead and rotting trees. One such trough measured had a total
volume of about 1040 cubic inches. Since no evidence was found of work
on living timber, we do not believe that the birds work on any wood that
is not dead and populated with insect larvae or ants.
Examination of the stomach contents of two pileated
woodpeckers taken at Aspen Valley, October 16, 1915, and Sweetwater
Creek, near Feliciana Mountain, October 30, 1915, showed each to contain
more than a hundred carpenter ants (Camponotus herculaneus
modoc). In addition one contained a whole manzanita fruit
(Arctostaphylos sp.) and the other, 4 large beetle larvae
(Cerambycidae) evidently dug out of some dead tree, for the stomach
contained also slivers of dead wood (H. C. Bryant, 1916, p. 32).
The Northern Pileated Woodpecker sometimes departs
widely from its usual diet of beetle larvae and ants. For instance, on
Sweetwater Creek, near Feliciana Mountain, in late October one was seen
feeding on the ripened fruits of the Nuttall dogwood. Because the
terminal branchlets which bear the fruit are small and slender, the big
bird was forced to hang inverted, chickadee-like, except when the
clusters could be reached from a main branch. When suspended on a
swaying stem the bird would peck at the fruits in the same manner, and
apparently with as much energy, as when digging into a dead fir stub.
Its changes of position, made after one fruit cluster had been consumed
and it sought another, were accompanied by much flapping of wings and
shaking of branches, and usually by the loud kuk, kuk calls.
These calls seemed to be given with the bill closed or at most only
slightly opened.
It does not seem likely that the work of the pileated
woodpecker, large as it must be in total quantity, is in any serious way
detrimental to the forest. On the other hand, the birds are probably of
material aid in felling dead timber that would otherwise continue to
occupy a place in the forest, to the discouragement of younger, growing
trees.
Two nest sites were seen by us. Near Yosemite Point
on June 4, 1915, two or three holes, of the size for a pileated
woodpecker, were located about twenty feet above the ground in a huge
dead and rotting fir. Two birds were about and seemed attached to the
locality. In Aspen Valley, at dusk on the evening of October 16, 1915, a
bird of this species was seen to enter a nest hole about forty feet up
in a dead white fir stub. This instance would suggest that these birds
may make use of old nesting holes as night shelters during the winter
months.
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