THE BIRDS
ANNA HUMMINGBIRD. Calypte anna (Lesson)
Field characters.Largest
of the hummingbirds found in the Yosemite region. Male with whole top of
head, chin and throat iridescent magenta or rose-red; lower surface
grayish green. Back in both sexes metallic green; no rufous or buffy at
all in plumage. Female (plate 46b) with sides of body tinged with
greenish, and with outer tail feathers broadly rounded at ends.
Voice: 'Song' of male a high-pitched squeaky
zeezy-zeezy-reezy-zee, etc., ending usually e-zeent',
e-zeent'; females utter a low-toned sucking note, tsup, when
foraging.
Occurrence.Common
resident of Upper Sonoran Zone on west slope of Sierra Nevada. Seen at
Pleasant Valley, near Coulterville, and at El Portal. Observed also in
Yosemite Valley on July 15, 18, and 28, August 25 and September 5 and 6
1920 (C. W. Michael, MS); also September 8, 1917 (J. Mailliard,
MS).
The Anna Hummingbird is the best known of the
California hummingbirds, chiefly because it is resident throughout the
year almost wherever found, and is common in the most thickly populated
parts of the state. It is common throughout the year at El Portal which
is at the upper margin of the Upper Sonoran Zone. Although this bird was
not observed by our party in Yosemite Valley it has been seen there in
late summer and early fall by other persons as detailed above. It
appeared at Smith Creek, east of Coulterville, on July 13, 1920, and was
present in numbers at the end of that month.
During November and December of 1914 we saw
individuals almost daily at El Portal. At this time of the year there
were no flowers of any sort to be found in the vicinity, but the Anna
Hummingbirds seemed to find enough good forage on the foliage of the
golden oaks, about which they were seen almost exclusively. The minute
insects which live on the leaves of the golden oak probably afforded
sufficient forage of one sort, but the hummingbirds had another source
of food supply.
It was noted that one or more Anna Hummingbirds were
to be found regularly about a certain golden oak, but the reason for
their attraction to this particular tree was not discerned for several
days. Then, on December 11, one of these birds was seen hovering before,
and drinking from, some punctures made by a Red-breasted Sapsucker in
the bark of the oak tree. The hummer visited puncture after puncture
just as it would the individual blossoms in a spike of flowers, and
evidently partook of both the sap and the smaller of the insects which
had been attracted by the sap. Ruby-crowned Kinglets and California
Woodpeckers were also visiting the place, in addition to the sapsucker
which had done the work. Thus the hummers, kinglets, and woodpeckers
were all benefiting by the industry of the sapsucker without evident
disadvantage to the latter, whereas all profited at the expense of the
oak tree.
In May, Anna Hummingbirds were foraging among the
flowers on the greasewood slopes about Pleasant Valley. A female taken
at this time (May 30) had a yolk in the ovary; this would suggest
breeding activity at a relatively late date for this species here. It is
elsewhere known to nest as early as February, or even January.
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