Archilochus Alexandri (Black-Chinned Hummingbird)

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.