The female Madeira firecrest builds a spherical nest from cobwebs, moss and small twigs, and she incubates the eggs and broods the chicks on her own.

It has bright olive-green upperparts with a bronze-coloured patch on each shoulder, and whitish underparts washed with brownish grey on the breast and flanks.

The head pattern is striking, with a black eye stripe, white supercilium and a crest which is yellow in the female and mainly orange in the male.

[2] Juveniles have a grey tinge to the duller upperparts, and lack the crown and eye stripes and supercilium;[3] by their first winter, only the flight and tail feathers remain unmoulted, and the young birds are virtually indistinguishable from the adults in the field.

[4] The calls of both species include high-pitched fine vocalisations zuu zu-zi-zi, although the Madeiran firecrest also has a distinctive shrill wheez and a whistled peep.

A phylogenetic analysis based on the cytochrome b gene showed that the Madeiran form is distinct at the species level from the firecrest nominate subspecies R. i. ignicapillus.

[10] The split was accepted by the Association of European Rarities Committees (AERC) in 2003,[11] but some authorities, such as Clements, have not yet recognised the new species.

[12] The International Ornithological Congress' recommended English name for this species was "Madeiracrest",[13] but this has been changed to "Madeira firecrest".

[18] Cytochrome b gene divergence between common firecrests from Europe and Madeira firecrests suggests an evolutionary separation roughly 4 million years ago,[10] considerably earlier than the 2.2 million years ago maximum estimate for the goldcrest radiations in the Canaries and Azores.

It occurs mainly at higher levels from 600 to 1,550 m (1,950–4,900 ft) in all types of forests and scrub,[19] but with a preference for tree heaths.

As is typical for the family, the nest is a closed cup built in three layers with a small entrance hole near its top.

[20] All Regulus species are almost exclusively insectivorous, preying on small arthropods with soft cuticles, such as springtails, aphids and spiders.

The Madeira firecrest also forages in the moss and lichen which often covers the branches and trunks of laurel and oak trees.