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Ruby-crowned Kinglet | Corthylio calendula
Roodkroonhaantje | Reyezuelo de moño rojo
One of the smallest songbirds on the continent: barely six grams, olive-green, with a broken white eye ring and two white wing bars. The male carries a scarlet crown patch that stays hidden nine times out of ten and rises like a small flame only in excitement. For a bird of this size the song is extravagantly loud.
Voice
The song opens with a few very high, thin see see notes, drops into a lower tew tew tew and ends in a loud, tumbling series of repeated triplets, tee-da-leet tee-da-leet. That ending is so powerful that anyone who does not see the singer consistently judges it a much larger bird. The call is a dry, two-syllable je-dit, hard and rattling, given all year and the sound that gives it away in a winter thicket. It sings mainly on the breeding grounds and on passage in early spring.
Recording: Jonathon Jongsma — CC BY-SA 4.0 · Miesville Ravine Park Reserve, Goodhue County, Minnesota, United States · xeno-canto
Identification
Small, round and short-tailed, olive-green above and dirty white to yellowish below, with two white wing bars, the rear one bordered by a black patch. The strongest mark is around the eye: a broken white ring that gives the bird a startled expression. The male has a red crown patch shown only in display, dispute or alarm; female and juvenile lack it entirely. The bill is short, thin and sharp, the legs dark with paler toes. The tail is short and slightly notched, which makes the silhouette look rounder still.
Confusion species
Golden-crowned Kinglet (Regulus satrapa) has a yellow or orange crown stripe bordered in black that is always visible and a striped head, but no eye ring. Hutton's Vireo (Vireo huttoni) of the west is a close match, with the same eye ring and wing bars, but has a heavier bill hooked at the tip and moves deliberately instead of restlessly. Yellow-rumped Warbler is larger and longer-tailed and carries a yellow rump patch. When in doubt the bill settles it: on this bird it is as thin as a needle.
Habitat
Breeds in dense, tall conifer forest of spruce and fir, in the boreal woods and in the mountains up to the treeline, favouring closed stands. Outside the breeding season it is far less particular: deciduous woodland, thickets, riverside scrub, gardens, parks and even the thorn scrub of desert margins. What it looks for is foliage holding insects, of whatever kind. Bare open country is avoided, but a single line of bushes is enough.
Where the bird is most often found, arranged by the USNVC — the vegetation classification of the United States and Canada — and CMECS for sea and coast.
Range and movements
Breeds from Alaska and northern Canada to Newfoundland, and south through the Rocky Mountains and the Sierra Nevada into Arizona and New Mexico; in the east the breeding range reaches Maine and the northern Great Lakes. Winters from the southern United States and the Pacific coastal belt south through Mexico, with the southern limit around Oaxaca; only exceptionally does it reach Guatemala. In the west the mountain birds simply drop into lower valleys for the winter, so that it is present there all year. For most of the United States it is one of the commonest migrants of April and October.
- Resident
- Breeding (summer)
- Winter
- Passage
- dark = core range, pale = thinly spread
Where and when to look
Hear it first, look second: the dry je-dit from a bush is, over much of the region in winter, the single commonest sound there is, and it repays learning by heart. To see the red crown, wait until two males meet; in migration that happens several times a morning in any patch of scrub. In winter look along the sunny side of a woodland edge in the first hour after sunrise.
Conservation
Very numerous and stable, with a population of around one hundred million birds. Logging and wildfire in the boreal breeding range are the main threats, but disturbance and fragmentation in themselves are tolerated well. In winter and on migration glass takes a heavy toll, because a small night migrant of this kind ends up in and around towns in large numbers.
Scientific name
Corthylio calendula | (Linnaeus, 1766)
Linnaeus described the species in 1766 as Motacilla calendula, among the wagtails; because it has since changed genus, author and year stand in parentheses. He took the epithet from Brisson, who in 1760 had called the bird Calendula pensilvanica after the region the specimen came from. For a long time it stood with the other kinglets in Regulus, but AviList places it in its own genus Corthylio, introduced by Cabanis as early as 1853 from Greek korthulos, a small bird named by the lexicographer Hesychius; it is larger than the other kinglets, wears a red rather than a yellow crown and sounds different. The described specimen came from Pennsylvania; that locality was later restricted to Philadelphia.