Bird Bio: Ruby-crowned Kinglet

Bird Bio: Ruby-crowned Kinglet
By: Bob Frey, KBO Biologist

In the vast boreal forests of Alaska and Canada, follow asubtle and melodic song and you’ll find one of North America’s smallest birds—the Ruby-crowned Kinglet. It is one of the many bird species that undertakes the great spring migration to the boreal regions to breed and nest. This species flies from wintering areas located within the southern one-third of the United States through Central America to Honduras. South of the United States border, it is known as “Reyezuelo de Rojo” (“Little King of Red”). Here in southern Oregon, we see these little kings (and queens) from late winter until their big flight northward or to higher elevations in our own region.

One of the world’s six kinglet species (two of which are found in North America), this diminutive olive and paleyellow songbird can be recognized by its nearly constant wing flicking, incomplete white eye-ring, and tiny bill. In courtship, or when agitated, the male flashes his regal ruby-red crown (female lacks this crown), which is otherwise hidden by olive-green feathers. Both male and female build a nest of moss and cobwebs, and together raise the young. Kinglets hop and twitter amongst the leaves and crevices of branches of conifer trees searching for their favorite foods—insects, larvae, and spiders.

Although considered common in most of its range, study of population trends for the Ruby-crowned Kinglet reveal a mix of results. Breeding Bird Survey data during the period 1966-2005 show it declining in numbers annually at a rate of 0.9 % across North America. Within Oregon, during the same period of time, it has declined 1.7 % annually. Populations of eastern North America have shown increases in recent years.

From 1996 through 2005 KBO biologists have captured and banded 1,605 Ruby-crowned Kinglets during monitoring efforts in the Klamath-Siskiyou Bioregion.

This article appears in KBO’s Spring 2006 newsletter. 

References:

Birds of Oregon edited by D.B. Marshall, M.G. Hunter, & A.L. Contreras; North American Breeding Bird Survey, Results and Analysis, 1966-2004 by J.R. Sauer, J. E. Hines, & J. Fallon; The Sibley Guide to Bird Life and Behavior by D.A. Sibley

Photo: Ruby-crowned Kinglet in the hands of a biologist at a KBO Banding Station. photo-KBO file