From Opus

Photo by Michael Woodruff. Photographed in Spokane, Washington. May 2004.

Vireo cassinii

[edit] Identification

11-14 cm. Grey head, flanks, and whitish underparts, yellow flanks, olive green-grey back, bright green rump, brown black wings and tail, dull olive green side to chest, solid white eye spectacle, 2 white wing bars, brown iris, black, grey based bill, grey blue legs. Sexes similar, female slightly duller.

[edit] Similar Species

Blue-headed Vireo has brighter yellow flanks and more contrast between the head and back.

Plumbeous Vireo is duller with little contrast between the head and the back and lacks yellow on the flanks.

[edit] Distribution

Breeds from British Columbia and southwestern Alberta through central Idaho, across to coastal Washington and Oregon, south to southern California and in Baja California, Mexico. Recent results suggest that at least part of the US population after having bred in early parts of summer migrates to north-western Mexico where a second round of breeding takes place.

A small number overwinter in southeastern Arizona, while the winter range mostly involves Mexico but for some birds may extend south to Costa Rica.

[edit] Taxonomy

Two subspecies are recognized:

• cassinii in most of range
• lucasanas in Baja California

Formerly lumped along with the Blue-headed Vireo and Plumbeous Vireo into one species, the Solitary Vireo.

[edit] Habitat

Open woodland.

[edit] Behaviour

The diet includes insects.

Its nest is a cup made from bark strips and down; 2 to 5 white, brown spotted eggs are laid.

[edit] References

1. Clements, James F. 2007. The Clements Checklist of Birds of the World. 6th ed., with updates to October 2007. Ithaca: Cornell University Press. ISBN 9780801445019
2. Paper describing migration to second breeding area

Wikipedia; All About Birds

• List of references

[edit] External Links