A “tiny, plump neurosis with feathers” is how the ruby-crowned kinglet is described in Birds of Northern California by Quady et. al. (2015). This hyperactive bird is constantly flitting about while flicking its wings.
Ruby-crowned kinglets (Regulus calendula) are among the smallest of songbirds weighing less than a third of an ounce. They are greyish green above and paler below. The short tail is notched, the slender legs are black with yellowish feet and the bill is thin and tiny. There is a white broken eye ring and black coloration below the larger white wing bar. Males and females look similar except the males have a red crest which they display during courtship or when agitated. Leonard and I watched the pictured bird interact with other ruby-crowned kinglets for quite a while. Other birds displayed their red crest but this one never did so we assumed it was a female.
In the summer ruby-crowned kinglets are difficult to see because they nest high in conifers. During migration and in winter they are much easier to see as they forage in thickets and deciduous woods. This kinglet was photographed in May amid the willows along the shore of Elkins #1 Pond in Ash Creek Wildlife Area near Lookout CA (Modoc County).
The diet of a ruby-crowned kinglet consists mainly of insects. They feed by gleaning but will also hover to pick insects off of foliage. In winter these small dynamos will also eat some seeds and berries. They have also been observed eating oozing sap and visiting flowers, probably for insects, but perhaps for nectar.
A previous post (“Ruby-crowned Kinglet” on 12-15-11) contains additional information about this charming little bird.