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Species Profile:
White-throated Sparrow
The White-throated Sparrow (Zonotrichia albicollis)
is found at one season or another throughout
most of North America east of the Rocky
Mountains.
The clear, whistled song, often written
as
"Oh, sweet Canada, Canada"
is familiar
to anyone who spends time in Ontario's
cottage
country.
During migration and in winter White-throats
often visit feeders, where their favourite
food is millet, but they also eat many
grass
and weed seeds as well as some fruit.
In
early spring, they eat a variety of
buds,
but insects form a larger proportion
of their
diet as they become more abundant.
Their
nest is a bulky open cup of woven grasses,
twigs, wood chips and needles, lined
with
finer materials. Nests are usually
on or
slightly above the ground, and are
well-concealed
from above by overlying vegetation.
Four
eggs are commonly laid of a very pale
or
greenish blue, speckled or blotched
with
chestnut-red or purple.
Although White-throats are common breeding
birds in eastern Canada, they are migratory,
and most spend the winter in the southeastern
United States. During migration, they
take
off at dusk and fly during the night,
as
do most sparrows. Unfortunately, during
their
spring and especially fall migrations,
many
are killed by flying into lit buildings.
(They are one of the most common species
found by FLAP.) This probably reflects
their
abundance rather than any special tendency
to fly into buildings.
The White-throated Sparrow is one of the
most variable of American sparrows.
Unlike
some sparrows (such as towhees and
longspurs)
there is little sexual difference in
plumage
colour (females are a bit duller on
average).
They are, however, polymorphic, i.e.
they
come in two different colour types
or "morphs":
tan and white. White morphs have a
bright
white throat, and white stripe above
the
eye and median crown stripe, whereas
tan
morphs have a whitish throat, but tan
striping
otherwise. Although they generally
have unstreaked
underparts as adults, some individuals
(especially
females) have distinct, if faint, streaking.
Males are slightly larger than females
(the
wing lengths of males are 69-78mm while
females'
are 64-72mm).
White-throats can be mistaken for their cousins,
White-crowned Sparrows which also have
black
and white-striped heads. White-crowns
are
somewhat larger, slimmer birds with
a grey
neck & throat and a yellowish bill
(White-throats
have a brownish bill). But what really
sets
them apart is the trademark yellow
spot between
the bill and the eye of the White-throat.
James Rising
Jim is Professor of Ornithology at the University
of Toronto. He has a special interest
in
sparrows.
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