Ruby-crowned Kinglet

Very common in Sonoma County woodlands during the winter months. It's not unusual to see dozens in a couple of hours of walking in the woods. Usually arrives in late September and may stay as late as mid-May the following year, but most are gone by the end of April. Often solitary, but may be seen in loose mixed flocks with Oak Titmouse, Chestnut-backed Chickadee, nuthatches, warblers, and the like. Common also in urban parks and suburban settings with adequate vegetation. Gleans small insects in wooded environments and brushy undergrowth, foraging frenetically, never sitting still, often flicking its wings. Although Ruby-crowned Kinglets are common and rather unafraid of people--often coming within a few feet of observers--they are very difficult to photograph because they never sit still.

Prominent eyering, incomplete above the eye; a drab olive color above, pale below; two white wing bars, the lower one being the longer and more prominent; a sharply pointed, black bill; dark legs (although the feet are often yellowish); fine yellow-gold striping on folded wings and tail; ruby spot on the crown (usually hidden).

Often confused with Hutton's Vireo (Vireo huttoni). Hutton's Vireo is a little bigger and has a more elongated look. Ruby-crowned Kinglet is a rather plump little bird with a proportionately short tail that adds to the impression of compactness (although kinglets are very inquisitive and fairly fearless; when they stop to look at you from a few feet away, they often stretch their necks and turn their heads, which gives them a rather different, less pudgy shape). Hutton's Vireo has a small, sharp bill with a tiny hook on the end, but Ruby-crowned Kinglet has an even finer, sharper bill lacking the hook. Both birds have two white wing bars, but Ruby-crowned Kinglet has also a dark area beneath the lower wing bar, lacking in Hutton's Vireo. The darkest part of a Hutton’s Vireo’s wing will be between the wing bars. Also note the fine greenish-gold edgings on the folded wing and tail feathers in the kinglet. While the vireo may show similar edgings, they usually have a more distinct greenish-gold look in the kinglet, in my experience. Ruby-crowned Kinglet has a patch of red feathers on its crown (hence the name) that Hutton's Vireo lacks, but the kinglet rarely shows its crown, so lack of a visible red spot on top of the head by no means rules out Ruby-crowned Kinglet. If you see a flash of red, however, you can be sure your bird is the kinglet. The vireo's legs are heavier and paler in color than those of the kinglet, which has notably skinny, usually black legs (but see “Foot Color” below). Behaviorally, the kinglet is a much more nervous bird--constantly flitting from place to place, flicking its wings. Hutton's Vireo flits about looking for insects, too, but rather more deliberately than the kinglet (that said, the vireo may flick its wing as well, so that alone is not enough to separate the birds in the field). Vocalizations are quite different. Ruby-crowned Kinglet is frequently detected before it's sighted by its chattering, which is often said to sound like the clatter of an old-fashioned typewriter (links below).

Superficially resembles Pacific-slope Flycatcher (Empidonax difficilis) because of the similar eyering, but that bird is larger and has the typical alert, upright look of a flycatcher, has a pale orange lower mandible, and has a slightly crested look. It behaves very differently. It behaves like a typical flycatcher--perching, flying out to catch an insect, and then perching again, often in the same spot--rather than hopping around in trees foraging, although Ruby-crowned Kinglet will flycatch as well, but usually hovering near branch tips to pick off insects rather than repeatedly flying off a perch.

Foot color: One thing I'm curious about is foot color. I've noticed that Ruby-crowned Kinglets generally have yellowish feet. Some have very yellow feet. In other birds, there's merely a suggestion of yellow, so the feet look brownish. The field guides often ignore this detail. Is it a purely random feature? Sibley shows the feet very yellow, without comment. The National Wildlife Federation guide illustrates a bird with somewhat yellow feet (using a photograph) and says the soles of the feet of the kinglet are yellow (although clearly some birds have entirely yellow feet). The 6th edition of the National Geographic guide shows a bird with yellow feet without comment, while the previous edition shows birds with black feet. The birds in the Peterson guides have black feet, although with a suggestion of yellow on the "shins."