Kinglets

This article first appeared in the January 2006 issue of the San Antonio Audubon Society newsletter.

In Zen, there is a saying: “Miraculous power and marvelous activity; chopping wood and fetching water,” the point being that we often overlook the remarkable in the common things around us. Perhaps no birds fit this theme better than do our two species of kinglets, the Ruby-crowned Kinglet (Regulus calendula) in particular being common enough around here during the winter that finding one becomes ordinary and perhaps an occasion for disappointment that it wasn’t something rarer.

The arrival of these many kinglets each winter mirrors a much larger event, that being the nocturnal rivers of birds that pour across our skies each year in such numbers that, if each individual migrant shone like a star, they would light up the night skies with myriad constellations. These migrations are all the more remarkable for the small size of many of the birds involved, the kinglets being among the very smallest of these. With weights averaging 6.5 grams or less (equal to about two hummingbirds), our two kinglet species average smaller than our warblers (7.5-25 grams), smaller than our titmice (10-21 grams) and smaller than our wrens (9-39 grams).

The large numbers of kinglets that descend upon the Lower 48 each fall also reflects another remarkable fact: the enormity of the remote woodlands where most of these birds breed. The drab kinglet in your back yard may have been hatched earlier that same year in a delicate woven cup, hidden high in a conifer in some distant wilderness far to the north where wolves still howl.

Long placed with the Old World Warblers in the Family Sylvidae, the kinglets have more recently been elevated to Family status; the Regulidae, with all six species in the genus Regulus. All the kinglets are small, drab, insectivorous birds breeding in mixed or coniferous woodlands across the Northern Hemisphere. Males have patches of brightly-colored feathers on the crown that are raised in display and during aggressive altercations. The males are territorial during the breeding season, the volume of their songs often surprising given the tiny size of the singer.

Kinglets form monogamous breeding pairs, the females alone constructing the deep cup-shaped nest, most often hidden in the fork of a spruce twig in dense foliage and often placed high in the canopy. Kinglets are known for their remarkably large clutch sizes, up to eleven eggs being incubated by the female, the weight of a large clutch equaling about three-quarters of her body mass. Both sexes tend the nestlings, the young fledging about five weeks after the start of incubation. The Golden-crowned Kinglet (R. satrapa) is commonly double-brooded, the female leaving the first brood in the care of her mate while she begins a second nest.

Our two species of kinglets differ in the particulars of their habitat preference and foraging styles. Both breed in northern or high-altitude forests and both species glean small insects, spiders and spider eggs from the foliage. The frequent wing flicks common to this family are thought to function in flushing prey. Of the two species, the larger (6.5 gram) Ruby-crown will breed in mixed woodlands, differing from the Golden-crown in that it often forages in broad-leafed trees and more often fly-catches or hovers while foraging. These habits are reflected in the relatively broader wings, longer legs, wider bill and longer rictal bristles of this species. In winter, the Ruby-crown is less tolerant of cold, wintering from the southern U.S. south to Central America, occurring in a variety of brushy or wooded habitats

The shorter legs, larger feet, and shorter, narrower and deeper bill of the Golden-crown allow it to feed while hanging from the ends of spruce twigs, probing the foliage. In summer, it prefers coniferous woodlands and is often found in conifers in winter. The foraging style of this species allows it to winter farther north than does the Ruby-crown. The Golden-crown shares with the related Old World Goldcrest (R. regulus) the distinction of being, at only 6 grams, the smallest birds known to commonly endure extreme cold without entering a torpid state, flocks of these birds clustering together for warmth on cold nights.

Perhaps you can stop and reflect when you see your next kinglet, and have a Zen moment.

Top photo: Ken Rush <http://www.watchingwildlife.com>