French: Viréo de Cassin German: Cassinvireo Spanish: Vireo de Cassin
Fort Tejon, California, USA
Subspecies and Distribution
V. c. cassinii
Xántus, 1858 – SW Canada (S British Columbia S from c. 53° N, SW Alberta) and W USA (Washington and W Montana S to S California), disjunctly also in NW Mexico (mountains of N Baja California); migrates to S California (rare) and Arizona S to W Mexico (S to Oaxaca).
V. c. lucasanus
Brewster, 1891 – S Baja California (NW Mexico).
13·5–14 cm; 10–20·6 g. Nominate race has eyering and area above lores white ("spectacles" on face), crown to nape and upper back dull... read more
Primary song, by male alone, a series of disjointed phrases, each consisting of 2–4 burry... read more
Nominate race breeds in various forest types, including coniferous, deciduous and mixed stands;... read more
Food and feeding
In breeding season bulk of prey arthropods, especially caterpillars (Lepidoptera), bugs (Hemiptera) and treehoppers (Membracidae), beetles... read more
Egg-laying starts late Apr in S to third week of Jun in N, later in interior locations than at coastal ones; no information on sedentary... read more
S Baja California race (lucasanus) sedentary. Nominate race wholly migratory, with... read more
Status and conservation
Not globally threatened. Common. Over much of its range present in substantial densities, with quoted figures of up to as many as 13·7 pairs/40 ha in lightly thinned forest... read more
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