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Text 16
WHO'S WHO AMONG THE CHICKADEES
All winter long, black-capped chickadees are among the most common
visitors at bird feeders over much of the northern part of North America. But
when spring arrives, these familiar little birds usually disappear from the
feeders, almost as though they have left the area.
Actually, these chickadees are year-round residents over most of their
range. The birds don't leave their winter neighborhoods, but abandon the feeders
as they switch diets to their more natural fare of caterpillars and other insect
food. At the ваше time, they adopt a different social organization. They are
preparing for the breeding of the next generation, the crucial act of survival for
all species. In the spring the successful ones will be frantically feeding clutches
of five to nine nestlings - extending the black-capped chickadee life-line into un-
certain future.
In the spring and summer, chickadees live in monogamous breeding pairs.
Bach pair of successful breeders stakes .out and de fends a territory against all
other black-capped chickadee. Territories, up to one-fourth of a square mile, must
contain an adequate supply of natural food as caterpillars, for both adults and
nestlings. They must also have at least one suitable nest site, typically a rotten tree
stump where chickadees can dig out a hole for their nest. The entrance is usually
on the side of the stump, although it is not uncommon for it to be on the top. Both
sexes share In the excavation duties; often several potential sites are dug out
before the final selection is made. .Only the female builds the nest, although her
mate often accompanies her closely while she works. When the clutch is
completed, the female incubates, while the male defends the territory and brings
food for his mate on the nest. When the young hatch, both parents bring food for
their nestlings. After leaving the nest, young chickadees generally remain
dependent on their parents for up to four weeks before dispersing, often moving
several miles away before settling down on their own.
At the end of the summer, a major social shift occurs. The older birds,
undergoing post-breeding molt, no longer defend their breeding territories but
gradually come together with several of the newly fledged young chickadees to
form flocks. These flocks will Occupy and defend a flock territory (usually -two
to three times the size of a breeding territory) against neighboring chi-cadee
flocks. They persist through the winter until the birds break up into breeding
pairs the following spring.
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