| Species: Gray Catbird
Dumetella carolinesis
Description:
The Gray Catbird
was named for its mewing call, although few people would mistake the
sound of this bird for that of an actual cat.
Identification:
General: A
member of the Mimid family the Gray Catbird is names for its cat
like call. Like many members of the Mimidae it also mimics the songs
of other birds, as well as those of tree frogs, and even mechanical
sounds. The Gray Catbird belongs to the genus Dumetella, which means
“small thicket” which is the perfect description of the habitat
favoured by this skulking bird.
Small (length 21–24
cm, mass 23–56 g) with relatively short wings and long tail; both
wings and tail rounded. Three to 4 long bristles (6–8 mm) at base of
straight bill. Upperparts of adult dark to blackish neutral gray,
underparts light to medium neutral gray. Crown, forehead, and tail
black. Undertail-coverts chestnut or neutral gray edged chestnut.
Adult Male:
Sexes indistinguishable.
Juvenile:
Juveniles are even plainer in colouration than adults, with buffy
undertail coverts
Similar Species:
Northern Mockingbird has white on its wings and tail and is larger
than Gray catbird. Townsend’s Solitaire’s are grayer with a pale
eyering and no black cap or rufous undertail coverts. The behaviour
is also very different from a catbird, sitting on high, exposed
perches. Catbirds are much grayer, with a black cap, long tail, and
thinner bill than either female Brown-headed Cowbirds or female
Brewer's Blackbirds.
Behavior:
Flights typically short and low, just above top of shrubs or through
small spaces among them; avoids flying across large, open space.
Wingbeat tempo is constant, even. Hops when moving along branches.
Travels through shrubs using combination of hopping and short
flights. In thickets setting, it builds a bulky, open nest, usually
within two meters of the ground. Although Brown-headed Cowbirds
(Molothrus ater) parasitize the Gray Catbird, they rarely are
successful. This catbird is one of only about a dozen species known
to recognize cowbird eggs and eject them from its nest—an ability
that is learned, not innate. On rare occasions, this learning goes
awry and an individual may come to recognize cowbird eggs as its own
and reject catbird eggs as they are laid.
Habitat: The
genus name, Dumetella, meaning “small thicket,” accurately reflects
the Gray Catbird’s habitat: dense, shrubby vegetation. Throughout
range found in dense shrubs or vine tangles; most abundant in
shrub-sapling-stage successional habitats. Gray Catbird density
increases linearly with shrub density. Also found in forest edges
and clearings, roadsides, fencerows, abandoned farmland and home
sites, pine plantations, streamsides, and some residential areas.
Information:
Like other species
in the family Mimidae, this bird displays considerable vocal
versatility. Part of this ability stems from the structure of its
syrinx. Because both sides of this vocal organ are able to operate
independently, the Gray Catbird can sing with two voices at the same
time. This species’ song is a long series of short syllables
delivered in rapid sequence. Its repertoire may include syllables of
more than 100 different types varying from whistles to harsh
chatters, squeaks, and even mimicry. These are sung in seemingly
random order at an uneven tempo, resulting in what often sounds like
an improvised babble of notes occasionally spiced with the familiar
mew.
Conservation
Status:
BC Yellow, COSEWIC
n/a, Global G5 (1996). Because this species prefers early
successional habitats, it probably benefits from some human
activity. For example, regenerating cutovers provide nesting habitat
in otherwise unsuitable forest. Likewise, suburbanization of wooded
areas, creation of forest edge by road or utility right-of-way
construction, and planting of shrubbery around homes and offices
have probably increased habitat availability on breeding grounds.
Conversely, elimination of fencerows surrounding agricultural fields
has likely decreased habitat at the same time. Because this species’
wintering grounds are largely coastal (areas of rapid human
population growth and construction), potential for human impacts
there are great. During migration, large numbers are occasionally
killed by colliding with towers.
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