The common firecrest (Regulus ignicapilla), also known as the firecrest, is a very small passerine bird in the kinglet family. It breeds in most of temperate Europe and northwestern Africa, and is partially migratory, with birds from central Europe wintering to the south and west of their breeding range. Firecrests in the Balearic Islands and north Africa are widely recognised as a separate subspecies, but the population on Madeira, previously also treated as a subspecies, is now treated as a distinct species, the Madeira firecrest, Regulus madeirensis. A fossil ancestor of the firecrest has been identified from a single wing bone.

This kinglet is greenish above and has whitish underparts. It has two white wingbars, a black eye stripe and a white supercilium. The head crest, orange in the male and yellow in the female, is displayed during breeding, and gives rise to the English and scientific names for the species. This bird superficially resembles the goldcrest, which largely shares its European range, but the firecrest's bronze shoulders and strong face pattern are distinctive. The song is a repetition of high thin notes, slightly lower-pitched than those of its relative.

The common firecrest breeds in broadleaved or coniferous woodland and gardens, building its compact, three-layered nest on a tree branch. Seven to twelve eggs are incubated by the female alone. Both parents feed the chicks, which fledge 22–24 days after hatching. This kinglet is constantly on the move and frequently hovers as it searches for insects to eat, and in winter it is often found with flocks of tits. Despite some possible local declines, the species is not the subject of significant conservation concerns owing to its large European population and an expansion of its range over the last century. It may be hunted and killed by birds of prey, and can carry parasites. It is possible that this species was the original "king of the birds" in European folklore.

Description

The common firecrest is a small plump bird, in length with a wingspan of ,

Taxonomy and systematics

thumb|A temporarily stunned adult male found on a pavement in [[Lille, France. The pattern on its head is seen clearly.]]

The kinglets are a small group of birds sometimes included in the Old World warblers, but frequently given family status, especially as recent research shows that, despite superficial similarities, the crests are phylogenetically remote from the warblers. The names of the family Regulidae, and the genus Regulus, are derived from the Latin regulus, a diminutive of rex, "a king", and refer to the characteristic orange or yellow crests of adult kinglets. The common firecrest was first formally described by Dutch zoologist Coenraad Jacob Temminck in 1820 as Sylvia ignicapilla; the relatively late identification of this common European bird arose from a perception that it was just a variety of the goldcrest. The species name is derived from Latin ignis "fire" and capillus "hair".

There are two widely recognised subspecies of common firecrest, nominate R. i. ignicapilla and Mediterranean R. i. balearicus (Jordans, 1923). The latter form is found on the Balearic Islands and in north Africa, and is slightly paler below and greyer above than the nominate subspecies. The Madeira firecrest, R. madeirensis, was formerly also considered to be a subspecies of the common firecrest, but phylogenetic analysis based on the cytochrome b gene showed that the Madeiran form is distinct at the species level. Cytochrome b gene divergence between the Madeira firecrest and the European bird is 8.5%, comparable with the divergence level between other recognised Regulus species, such as the 9% between the goldcrest and the golden-crowned kinglet. The island form also differs in morphology and vocalisations. The proposed split was accepted by the Association of European Rarities Committees (AERC) in 2003, with most other authorities also splitting it later on.

The flamecrest or Taiwan firecrest (Regulus goodfellowi) of Taiwan has sometimes been viewed as a race of the common firecrest; however, the flamecrest's territorial song, which resembles those of the Himalayan races of the goldcrest, and genetic data indicate that the flamecrest is closely related to the Himalayan goldcrest and only distantly to the two firecrest species. The kinglets on the Canary Islands, which were also considered to be close to firecrests, have now been shown to comprise two subspecies of goldcrest.

Fossils

There are a few Pleistocene (2.6 million to 12,000 years ago) records from Europe and Israel of extant Regulus species, mostly goldcrests or unidentifiable to species, but also a Spanish specimen of firecrest. A left ulna from Bulgaria was identified as belonging to a fossil species, Regulus bulgaricus, from 2.6–1.95 mya. This appears to be ancestral to the common firecrest, with the goldcrest diverging from this lineage in the Middle Pleistocene.

Distribution and habitat

thumb|Cork woodland is favoured for breeding.

The common firecrest breeds in lowland broadleaf forest, preferring cork oak and alder where available, otherwise beech and holly. It also uses mixed broadleaf and conifer woodland, and stands of spruce, European silver fir, cedar and pines, often with undergrowth of juniper, ivy and wild rose. In drier Mediterranean habitats it is found in conifers, evergreen oak, and mixed woodlands up to . In winter it is less reliant on conifers than the goldcrest, moving from forest to fringes and scrub. It occurs singly or in pairs, spending much time in the tree canopy, although frequently venturing into bushes and other lower vegetation.

The nominate subspecies breeds in Europe from southern England, France, Spain and Portugal east to Belarus, northwestern Ukraine, and Greece, and north to the Baltic and southern Latvia. There are isolated populations east of the main range in Abkhazia, the Crimea and Turkey. Its range lies between the July isotherms. Southern birds are largely resident, unlike northern and eastern populations which are migratory, wintering mainly in Mediterranean areas and the far west of Europe from Portugal north to Britain. R. i. balearicus is resident in the Balearic Islands and the northern parts of Morocco, Algeria and Tunisia. This species has been recorded as a vagrant from Norway, Finland, Estonia, Cyprus, Egypt and Lebanon. In July 2020, it was reported that the common firecrest was now nesting in at least two locations in southern Finland.

Behaviour and ecology

Breeding

thumb|Singing with crest displayed in a hazelnut tree. [[Capranica, Lazio|Capranica, Italy.]]

thumb|Eggs of Regulus ignicapilla – [[MHNT]]

The common firecrest is monogamous. The male sings during the breeding season, often with its crest raised, and has a display which involves pointing its bill at another bird, showing the crest and strong face pattern. This differs from the display of the plainer-faced goldcrest, which bows its head to emphasise the crest. The breeding territory is about , and may overlap with neighbouring goldcrest territories. Firecrests will sometimes defend their territories against goldcrests with the crest raised and a great deal of wing-fluttering, in other circumstances, the two kinglets learned to ignore each other's songs. In his courtship display the male firecrest raises his crest, points it towards his mate and hovers over her before mating takes place. As is typical for the family, the nest is a closed cup built in three layers with a small entrance hole near its top. The nest's outer layer is made from moss, small twigs, cobwebs and lichen, the spider webs also being used to attach the nest to the thin branches that support it. The middle layer is moss, and this is lined with feathers (up to 3,000) and hair. unlike those of Madeira firecrest which are described as like those of a Phylloscopus warbler (white with some brown speckles). The eggs are and weigh , of which 5% is shell. The clutch size in Europe is 7–12 eggs, but probably smaller in northwest Africa. The female incubates the eggs for 14.5 to 16.5 days to hatching, and broods the chicks, which fledge eight to ten days later. Both parents feed the chicks and fledged young.

Young common firecrests are fed almost exclusively with springtails; larger food items are not accepted, and spiders are occasionally regurgitated. From the fifth day onwards, the nestling diet includes aphids and a high amount of snail shells, the latter being needed for bone growth. After the second week, the food includes larger moths and caterpillars, as well as various arthropods typically avoided by adults, such as harvestmen, earwigs, and centipedes. In some areas, wintering birds have developed the habit of coming to feeding stations and bird tables for fatty food, sometimes with goldcrests or warblers such as the common chiffchaff and blackcap.

Voice

The contact call is three or four thin high notes, similar to that of goldcrest, but slightly lower in pitch, zit-zit-zit rather than see-see-see. Male goldcrests and Madeiran firecrests sometimes show a territorial response to recordings of the songs or calls of the common firecrest, but the reverse is apparently not true, because the songs of the common firecrest are simpler in construction than those of its relatives. The tawny owl relies more on mammalian catches, but about one-third of its food is forest birds. Eggs and young may be taken by grey squirrels, Eurasian jays and great spotted woodpeckers.

The invasive Argentine ant (Linepithema humile) is common in the Mediterranean area, and reduces arthropod numbers by removing most native ant species. The reduction in prey items is greatest in the tree canopy, and has a greater effect on species like the firecrest that feed high in the foliage. Less food is available for chicks, and parents have to spend more time foraging.

Data on specific parasites of the firecrest is lacking, but the widespread moorhen flea, Dasypsyllus gallinulae has been recorded in a related Regulus species. A number of feather mites have been recorded in the genus, including Proctophyllodes glandarinus on firecrest. These mites live on fungi growing on the feathers. The fungi found on the plumage may feed on the keratin of the outer feathers or on feather oil.

Status

The common firecrest expanded its range in the nineteenth and twentieth centuries, but first bred in 1962, A population was found in northern Morocco in 1986. There may also be localised losses in areas of high heavy metal pollution, which particularly affects ground feeders like thrushes and conifer foliage gleaners, including both European Regulus species. Conifer specialists suffer from the loss and poor quality of needles, and the consequent decrease in abundance of their invertebrate food. The common firecrest has a large range and a population estimated at 10–15 million individuals, most in Europe. The population is believed to be stable in the absence of evidence for any declines or serious threats, and it is therefore classed as least concern on the IUCN Red List. Following from this legend, in much European folklore the wren has been described as the "king of the birds" or as a flame bearer. However, these terms were also applied to the Regulus species, the fiery crowns of the goldcrest and firecrest making them more likely to be the original bearers of these titles, and, because of the legend's reference to the "smallest of birds" becoming king, the title was probably transferred to the equally tiny wren. The confusion was assisted by the similarity and consequent interchangeability of the Ancient Greek words for the wren (βασιλεύς , "king") and the crest (βασιλισκος , "kinglet"). In English, the association between the firecrest and Eurasian wren was reinforced by the kinglet's old name of "fire-crested wren".

References

  • Firecrest videos, photos & sounds on the Internet Bird Collection
  • Ageing and sexing (PDF; 2.7 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze