The Black-chinned
hummingbird or Archilochus alexandri is a common species of
hummingbird, popular in the western part of Central and Northern America.
These small hummingbirds are often misunderstood as
Anna’s and Costa’s hummingbirds, due to their metallic green color, but there
are some distinguishing factors that set this hummingbird apart from the rest.
Description
Black-chinned hummingbirds are also known as Alexander
hummingbirds. The bird was named after Dr. Alexandre, a French physician, who
was the first to discover this species of hummingbird in Mexico. Males have a black
head and chin, with a thin deep purple collar on the neck. The name
black-chinned hummingbird is, therefore, more commonly used to mention this
species.
Black-chins are sexually dimorphic, meaning that the male
and female look different from one another. As with other species of
hummingbirds the male is the more brightly colored and distinctive than the
female. The male can be identified by its black face. Its chin and upper throat
area are also black, but the lower throat area is an iridescent blue-violet.
This is bordered by a white collar below. The back and crown of the male is a
metallic green color. The tail feathers of the male are black. The females have
the same bright green back and crown, but differ by its green face, white
breast and throat area with a few black spots. The female Black-chin also has
white tips on the outer feathers of her tail. Both sexes have a white spot
behind their eyes and a straight long thin bill. The Black-chinned Hummingbird
is considered a small hummingbird, its length measuring 9.0 to 9.5cm. Females
are usually larger than the males, they weigh on average about 3.5 g., the male
average weight is 3.0 g.
Vocalizations
These hummingbirds do not sing, and their call notes are
a sharp, high “pip-pip-pip” that is repeated rapidly. When aggressive, they
also use a raspy chatter, and their wings create a metallic hum or trill in
flight.
Geographic
Range
The Black-Chinned Hummingbird, Archilochus alexandri, has
the most extensive breeding range of all northwestern hummingbirds. It
regularly occurs throughout western North America, from as far north as British
Columbia south to northern Mexico, and from coastal California to central
Texas, where its population is highest in density. During the winters, the
Black-chin migrates to southern California, southern Arizona, southern Texas
and Mexico (Peterson 1961; Gough et al. 1998).
Reproduction
The nest is built in about 3 days by the female
Black-chin. She selects a drooping branch of a bush or a fork in a tree limb
for the nest. The female collects the down of young sycamore trees or other
plants and binds them together with spider webs to give the nest an elastic,
feltlike quality. The small, deep cuplike nest measures about 3.5cm (1.5
inches) in diameter. The nest is able to stretch to double its size as the
young grow and need more room. Two to three tiny eggs are laid sometime between
early April to the end of September. They measure on average, 12 x 8mm. Newly
laid eggs are white with a pinkish tint, changing later to a dull white or gray
color right before they hatch. The incubation period usually lasts 13-16 days.
The offspring usually fledge after about 20 days (Cassidy 1990; Dawson 1923).
Food
Habits
The diet of the Black-chinned Hummingbird consists of nectar,
pollen, insects and sugar water from feeders. The black-chin prefers nectar
from flowers of Tree Tobacco Nicotiana glauca, Scarlet Larkspur Delphinium
cardinale, and Desert Ocotillo Fouquieria splendens. Black-chins dart out into
the open to catch flying insects or gleans them from foliage to provide the
protein necessary for proper development of their young (Terres 1980; DeGraaf
et al. 1998).
Justification
This species has an extremely large range, and hence does
not approach the thresholds for Vulnerable under the range size criterion
(Extent of Occurrence <20,000 km2 combined with a declining or fluctuating
range size, habitat extent/quality, or population size and a small number of
locations or severe fragmentation). The population trend appears to be
increasing, and hence the species does not approach the thresholds for
Vulnerable under the population trend criterion (>30% decline over ten years
or three generations). The population size is extremely large, and hence does
not approach the thresholds for Vulnerable under the population size criterion
(<10,000 mature individuals with a continuing decline estimated to be
>10% in ten years or three generations, or with a specified population
structure). For these reasons the species is evaluated as Least Concern.
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