Get to know Marin's bug-eating birds
Winter is a great time for attracting birds to your yard. The ubiquitous crowned sparrows have arrived. Year-round goldfinches eat shelled sunflower and Nyjer seed with a far greater appetite than in spring and summer. But there are some winter birds that eat mostly insects and are far easier to overlook, although they are reasonably common and can often be attracted to feeding stations: These include the rubycrowned kinglet, Townsend's and yellow-rumped warblers and the hermit thrush.
Ruby-crowned kinglets are probably the most widespread of these birds, but they are incredibly easy to miss. You might hope that a bird named “ruby-crowned” would bear a vivid signpost of identity on its head. You would be wrong. In the great majority of encounters, the ruby crown of the males is entirely invisible, typically revealed only in moments of aggression or agitation. Instead, identify kinglets by their tiny size, the white bar on their wings and their constant jittery movements accompanied by jittery “jid-dit” calls.
Despite their general inclination towards eating insects, winter's cooler temperatures and relative scarcity of prey encourage these birds to visit our offerings when needed.
The next of the neighborhood bug-eaters to be aware of are our two winter warbler species: the yellow-rumped warbler and the Townsend's warbler. Yellow-rumps are the more abundant of the two, frequently flocking in open woodlands, parks and neighborhoods. Fairly plain in their winter plumage, close observation will nonetheless detect the namesake yellow rump patches, as well as yellow on the throat and under the wings. Townsend's warblers are less numerous (they are typically encountered singly), but more striking, with plumage of vividly contrasting stripes of black and yellow.