Corthylio calendula
Order Passeriformes
Family Regulidae
♂ Adult male.— Upper parts gray, with a greenish tinge in strong light; crown with a partially concealed patch of flame-colored feathers; wing-bars whitish; under parts dull whitish.
♀ Adult female.— Lacks the crown-patch.
Nest, globular, of moss, etc., in an evergreen from six to sixty feet up.
Eggs, sometimes as many as ten, dull white, faintly speckled with buffy.
The Ruby-crowned Kinglet is a rather common migrant through New York and New England, in April, and again in October. It probably breeds sparingly in eastern Maine, but in the rest of New England it is unknown in summer. In the migrations it frequents the edges of woodland, or pastures overgrown with bushes and small trees. Like its relative the Golden-crowned Kinglet, it is often found in evergreens, either red cedar groves or the spruces in plantations. Its feeding habits are similar to its relative’s. It inspects the twigs with restless activity, frequently flitting its wings.
The harsh, grating call-note of the Ruby-crowned Kinglet is often the first thing that attracts our attention to it. Often the repetition of this note is followed by the song, a performance deservedly noted for its sweetness, brightness, and vigor; it may always be recognized by the high, thin introductory notes and by a phrase of three notes, tee’-dě-dī repeated several times toward the end of the song.
The song is often uttered in the fall.
When a male is excited, the feathers of the crown are slightly raised and show the flame-colored patch from which the term ruby-crowned has been derived. If two males pursue each other, the color actually seems to blaze forth, but often no color at all is visible. The species, nevertheless, may always be distinguished from the Golden-crowned Kinglet by the absence of any markings over the eye, the adult Golden-crown always showing at every season the black stripes inclosing the yellow crown. The eye of the Ruby-crown is surrounded by a whitish ring which makes it seem large and prominent for so small a bird.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)