kinglet

kinglet, common name for members of a subfamily of five species of Old and New World warblers, similar to the thrushes and the Old World flycatchers. Kinglets are small birds (4 in./10 cm) with soft, fluffy, olive or grayish green plumage and bright crown patches. Their distribution is circumpolar in the conifer belt. The two American species, the ruby-crowned and golden-crowned kinglets, breed in Canada and winter in Mexico. Similar are the Old World goldcrest and the European firecrest. They are active, insectivorous birds, traveling in loose bands together with nuthatches, woodpeckers, creepers, and titmice. Their hanging nests are purse-shaped. In the same order as the kinglets are the gnatwrens of Central and South America and the gnatcatchers, both of the family Polioptilidae, found from the N United States to Argentina. These dainty, slender birds are colored in soft grays and have thin, pointed bills; they feed on small insects. The blue-gray gnatcatcher of the United States and Mexico is typical of the group. Kinglets are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Passeriformes, family Sylviidae.

The kinglets or crests are a small group of birds sometimes included in the Old World warblers, but are frequently given family status because they also resemble the titmice. The scientific name Regulidae is derived from the Latin word regulus for "petty king" or prince, and comes from the coloured crowns of adult birds. This family has representatives in North America and Eurasia. There are seven species in this family; one, the Madeira Firecrest, Regulus madeirensis, was only recently split from Firecrest as a separate species. One species, the Ruby-crowned Kinglet, differs sufficiently in its voice and plumage to occasionally be afforded its own genus, Corthylio.

Kinglets range in size from 9 to 11 cm and are amongst the smallest of the passerines, and indeed of all birds. They have medium-sized wings and tails, and the tails of all species are incised at the tip. The bill is small and needle-like. The plumage is overall grey-green. Most have an eye-ring or a stripe at the supercilium, although the slightly atypical Ruby-crowned Kinglet lacks this. The males possess a colourful crown patch. They have one specific feather which projects forward over the nares (again lacking in the Ruby-crowned Kinglet).

Generally kinglets are adapted to conifer forests, although there is a certain amount of adaptability and most species will use other habitats, particularly during migration. They have a distribution that takes in the northern boreal forests, but also extend down as far as the subtropics in places. A number of insular populations have evolved into separate species and subspecies.

The tiny size and rapid metabolism of kinglets means that they must constantly forage in order to provide their energy needs. They will continue feeding even when nest building. Kinglets prevented from feeding may lose a third of their body weight in twenty minutes and may starve to death in an hour. Kinglets are insectivores, preferentially feeding on insects such as aphids and springtails that have soft cuticles. Prey is generally gleaned from the branches and leaves of trees, although in some circumstances prey may be taken on the wing or from the leaf litter on the ground.

The nest are small, very neat cups, almost spherical in shape, made of moss and lichen held together with spiderwebs and hung from twigs near the end of a high branch of a conifer. They are lined with hair and feathers, and a few feathers are placed over the opening. These characteristics provide good insulation against the cold environment. The female lays 7 to 12 eggs, which are white or pale buff, some having fine dark brown spots. Because the nest is small, they are stacked in layers. The female incubates; she pushes her legs (which are well supplied with blood vessels, hence warm) down among the eggs. The eggs hatch after 15 to 17 days. The young stay in the nest for 19 to 24 days. After being fed, nestlings make their way down to the bottom of the nest, pushing their still-hungry siblings up to be fed in their turn (but also to be cold).

Species

• Goldcrest, Regulus regulus - in most of Europe and Asia.
• Tenerife Goldcrest or Orangecrest, Regulus teneriffae, split from Goldcrest as separate species - in eastern Canary Islands.
• Firecrest, Regulus ignicapillus - in Europe and north Africa.
• Madeira Firecrest, Regulus madeirensis - in Madeira.
• Taiwan Firecrest or Flamecrest, Regulus goodfellowi - in Taiwan.
• Golden-crowned Kinglet, Regulus satrapa - in north America.
• Ruby-crowned Kinglet, Regulus calendula - in north America.

Regulus bulgarius is a prehistoric species known only from fossils. Its remains have been found in the Late Pliocene deposit of Varshets, Bulgaria.

References

• Alström, P.(2006, February). Phylogeny and classification of the avian superfamily Sylvioidea. Molecular Phylogenetics and Evolution, 38 (2). Retrieved March 2006, from http://portal.isiknowledge.com/portal.cgi
• Bent, A.C. (1964). Life histories of North American thrushes, kinglets, and their allies. New York: Dover Publications
• Crick, Humphrey (2003). Firecrests and Kinglets. In Perrins, Christopher, editor, The Firefly Encyclopedia of Birds. Firefly Books. ISBN 1-55297-777-3.
• Cumming, E.E. (2004) Habitat segregation among songbirds in old-growth boreal, mixed wood forest. Canadian Field-Naturalist. 118: 1: 45-55
• Del Hoyo, J.; Elliot, A. & Christie D. (editors). (2006). Handbook of the Birds of the World. Volume 11: Old World Flycatchers to Old World Warblers. Lynx Edicions. ISBN 849655306X.
• Gill, F. (1995). Ornithology. USA: W.H. Freeman.
• Hayes, J.P. (2003) Response of birds to thinning young Douglas-fir forests. Ecological Applications. 13:5: 1222-1232
• Heinrich, Bernd. (2003) Overnighting of Golden-crowned Kinglets during winter. Wilson Bulletin. 115:2: 113-114
• Humple, D.L.,et al. (2001) Female-biased sex ratio in a wintering population of Ruby-crowned Kinglets. Wilson Bulletin. 113:4: 419-424
• Podlesak, D. W. (2005). Stable isotopes in breath, blood, feces and feathers can indicate intra-individual changes in the diet of migratory songbirds. Oecologia, 142: 4: 501-510.

External links

• Kinglet videos on the Internet Bird Collection