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Wrens
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Small buffy songbird.
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Tail often held upward.
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Rusty underparts.
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White eyestripe.
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Loud.
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Size: 12-14 cm (5-6 in)
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Wing span: 29 cm (11 in)
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Weight: 18-22 g (0.64-0.78 ounces)
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Sexes look alike; male slightly larger
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Wrens are small, active birds, basically brown in color, that often
perch with their tails held straight up. They forage on or just above
the ground in thick brush, forest understory or marsh vegetation.
Wrens belong to Family Troglodytidae, with about 70 species in the
New World, most of them in the tropics. Only one species lives in
the Old World: the winter wren, which likely spread from Alaska to
Siberia and extended its range westward until, eons in the past, it
reached Britain and Iceland. Some wrens nest in cavities; others build
roofed structures out of plant matter. The males of several species
build "dummy" nests, preliminary nests placed in tree cavities,
woodpecker holes and nest boxes, and less frequently in odd enclosed
spaces such as tin cans, pockets of clothing hung outdoors, hats,
boots, flower pots and drainpipes. Later, a female will choose one
of the male's dummy nests, finish its construction, and lay eggs in
it. Wrens often pester other birds and evict them from nest cavities,
puncturing their eggs or pecking their young to death. They destroy
nests in cavities and in the open; they also wreck other wrens' nests.
Why such belligerence? Does an abundance of empty nests discourage
predators from looking further and finding an active wren's nest?
Or does killing its rivals' offspring reduce pressures on prey populations,
making it easier for a wren to feed its own young?
Wrens eat mainly insects and spiders. A few species will also feed
on berries and seeds. Owls, small hawks and house cats take adult
wrens; raccoons, opossums, minks, weasels, mice, squirrels, woodpeckers
and snakes raid wrens' nests. Some wrens migrate southward in winter,
while other species remain as permanent residents on their breeding
range. Five species are found in Pennsylvania.
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| Bird rescue & bird adoption;
parrot refuge/rescue & placement for unwanted birds. |
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| Check out our list of local
birds broken down by your state and different types of
species. |
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| Migrating birds stay on track
because of chemical reactions in their bodies that are
influenced by the Earth's magnetic field... |
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Part
I
November
19, 2004