Vanessa annabella

Common at all sites. At low elevations this species is more often seen in cool seasons. Adults "hibernate," but near sea level can be seen sunbathing and being territorial on sunny, mild days all winter long. There is probably some altitudinal migration, but no evidence of latitudinal migration as in V. cardui.

Vanessa atalanta

One of the most frequently seen butterflies in midwinter at low elevation, and often very common in the urban Bay Area, the Red Admiral occurs all around the Northern Hemisphere. It is multiple-brooded, overwinters as an adult, and may undergo altitudinal migration in the Sierra (where it is generally uncommon). Males are territorial in late afternoon in sites open to the W or SW, I.e. to the lowering sun. They often share these sites with West Coast Ladies and (when present) Painted Ladies, and sometimes other Nymphalids as well. Both within- and between-species chases are common.

Vanessa cardui

This mass-migrant occurs in much of the Northern Hemisphere. Apparently the entire North American population winters near the US-Mexico border, breeding in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north. In good years (lots of desert rain) they may do so by billions, interfering with traffic and attracting the attention of the media. 2005 was one of the biggest Painted Lady years in history--perhaps the biggest, but how can we know?

Vanessa virginiensis

Our least common Lady. It is easily told from the others by the very large eyespots on the hindwing beneath. Multiple-brooded, and occurs in a great variety of habitats at all elevations--but its seasonal life-history is poorly known. Is it migratory, either altitudinally or latitudinally? Where is it in the winter when, unlike our other Vanessa, it is never observed?