Newsletter / Blog
2011-12-11 Iowa State Bird – American Goldfinch.
The American
Goldfinch - Carduelis tristis - is migratory, ranging from Alberta to North Carolina
during the breeding season and from just south of the Canadian border to Mexico during
the winter. It is gregarious during the non-breeding season, when it is often
found in large flocks. This bird prefers open country where weeds thrive.
Description
The body of the
male is a brilliant lemon yellow with a striking jet black cap and white rump
when the spring molt is complete. The female is mostly brown, lighter on the
underside with a yellow bib. After the autumn molt, the bright summer feathers
are replaced by duller plumage, becoming buff below and olive-brown above, with
a pale yellow face and bib. The autumn plumage is almost identical in both
sexes, but the male has yellow shoulder patches. In some winter ranges, the
goldfinches lose all traces of yellow, becoming a predominantly medium tan-gray
color with an olive tinge evident only on close viewing. The beak is small,
conical, and pink for most of the year, but turns bright orange with the spring
molt in both sexes. The shape and size of the beak aid in the extraction of
seeds from the seed heads of thistle and other plants.
The immature
American Goldfinch has a dull brown back, and the underside is pale yellow.
Call
There are two
defense calls made by adults during nesting; a sweeet call made to rally
other goldfinches to the nest and distract predators and a bearbee used
to signal to the nestlings to be quiet and get them to crouch down in the nest
to become less conspicuous. The song is a series of musical warbles and
twitters, often with a long note. A tsee-tsi-tsi-tsit call is often
given in flight.
Food
It is mainly
granivorous, but will occasionally eat insects, which are also fed to its young.
Breeding
The American
Goldfinch begins its breeding season later in the year than any other finch. The
courtship rituals of the American Goldfinch include aerial maneuvers and
singing by males, who begin courtship in late July. The flight displays begin
as the male pursues the female, who flies in zigzagging evasive patterns. If a
female accepts the male as a mate, the pair will fly in wide circles, as the
male warbles throughout the flight. The nest is built in late summer by the
female and she lays four to six bluish/white eggs, which are oval. The eggs are
incubated by the female alone, with the male bringing her food. The chicks
hatch between 12 to 14 days after incubation begins. The male keeps
feeding the young for up to three weeks after the young have fledged.
Conservation Status – Least Concern
It is not threatened by human activity, and is widespread throughout its
range. The clearing of forests by humans, though harmful to many species, has
benefited the American Goldfinch.
Birdwatching
The American
Goldfinch is found in residential areas throughout its range. |