Western Bluebird - BirdForum Opus

Sialia mexicana

Male
Photo by Garrett Lau
San Jose, California, USA, April 2005

Identification

Length 16.5-19 cm (6.5-7 in), weight 24-31 g

• A dark blue-and-orange bluebird
• Appears round-shouldered when perched

Male:

• Blue head, wings, and tail
• Rusty orange-red back
• In some birds the back is partially or wholly blue
• Blue throat

Female
Photo by CalvinFold
Pleasanton, California, USA, May 2015

Female:

• Paler and duller
• Rusty breast
• Grayish throat and belly

Immature:

• Speckle-breasted and -backed
• Grayish
• No red
• Some blue in wings and tail

Similar species

• Eastern Bluebird is slightly paler blue above, orange (never blue) on the throat, and does not have any orange on the back; some females can be very hard to distinguish.
• Mountain Bluebird is much paler blue, and lacks orange tones, being pale blue (males) or greyish (females) below.

Distribution

West coastal states of central North America, from southern British Columbia south to northern Baja California, the four-corners states, and extending south through Mexico, east into western Texas, and north just into southern Wyoming.

A partial migrant, moving out of the colder parts of the range (British Columbia except for the Vancouver area, and areas east of the Cascades mountains and north of central Utah and Colorado) in winter, with birds arriving in lowland desert areas of Arizona and northern Mexico where they do not breed.

Taxonomy

Juvenile
Photo by bobsofpa
Azalea Campground, Kings Canyon National Park, California, USA, June 2007

Subspecies

This is a polytypic species consisting of six to eight subspecies depending on authority^[1][2]:

• S. m. occidentalis:

• Southern British Columbia to southern California and western Nevada.

• S. m. bairdi:

• South-western USA to north-western Mexico (Sonora and Chihuahua).

• S. m. anabelae (accepted by Clements^[1], not by IOC^[2]):

• Mountains of northern Baja California (Sierra Juárez and San Pedro Mártir).

• S. m. jacoti (accepted by IOC, not by Clements):

• South-central USA and northeast Mexico.

• S. m. amabilis:

• Sierra Madre Occidental of Mexico (southern Chihuahua to Zacatecas).

• S. m. nelsoni (accepted by IOC, not by Clements):

• Central Mexico. Very dark; mostly blue, with minimal orange.

• S. m. mexicana:

• Plateau of north-eastern Mexico (Coahuila to Nuevo León and Tamaulipas).

• S. m. australis (accepted by Clements, not by IOC):

• Southern plateau of Mexico (Jalisco to Morelos, Puebla and Veracruz).

Habitat

Photo by Michael Daniel Ho
California, USA

Open woodlands, riparian zones, agricultural areas. Deserts in winter.

Behaviour

Usually in pairs, but gathers in flocks in winter. Has favorite perches, from which it drops to the ground to pick up prey or captures flying insects mid-air, flycatcher-style.

Diet

The diet includes insects, worms, snails, and spiders, adding berries in season.

Breeding

Breeds in tree holes; often in nest boxes.

References

1. Clements, JF. 2009. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2009. Ithaca: Cornell Univ. Press. ISBN 978-0801445019.
2. Gill, F and D Donsker (Eds). 2016. IOC World Bird Names (version 6.3). Available at http://www.worldbirdnames.org/.

• List of references

Recommended Citation

• BirdForum Opus contributors. (2024) Western Bluebird. In: BirdForum, the forum for wild birds and birding. Retrieved 30 April 2024 from https://www.birdforum.net/opus/Western_Bluebird

External Links

Search for photos of Western Bluebird in the gallery