The Bohemian Waxwing (Bombycilla garrulus) is a starling-sized passerine bird that breeds in the northern forests of the Palearctic and North America. It features buff-grey plumage, a black face mask, and a pointed crest, with wings displaying white and bright yellow patterns, and red-tipped feathers resembling sealing wax. Females resemble males but younger birds lack distinct markings.
Adult Bohemian waxwings range from 19–23 cm in length and weigh about 55 g. They possess a conspicuous crest, a black mask, and striking wing features, including yellow stripes and red waxy tips. Males and females are similar but have slight differences in plumage characteristics. First-winter birds and juveniles display different traits, and the plumage of juveniles is duller.
The Bohemian waxwing is a starling-sized bird measuring 19–23 cm in length with a wingspan of 32–35.5 cm and an average weight of 55 g. It features a short tail, mainly brownish-grey plumage, and a prominent crest. Males have a black mask, throat, and a rich chestnut lower belly, while both sexes have distinctive wing markings and red waxy tips on the secondaries.
In adults, primary feathers have a bright yellow leading edge, with males showing 6–8 red wax tips. Females have a narrower yellow tail tip and fewer red tips. First-winter birds and juveniles differ in markings and colors, with juveniles having duller plumage.
The Bohemian waxwing’s range overlaps with the cedar waxwing, which is smaller and lacks certain markings, and the Japanese waxwing, which has distinct features. Its call is a high trill, and its flight creates a rattling sound when flocks take off or land.
The Bohemian waxwing has a circumpolar distribution, breeding in northern Eurasia and North America. In Eurasia, it nests just below the treeline, primarily between 60–67°N, while North American subspecies mainly breed in northwestern and north-central areas.
This migratory bird abandons its breeding range for the winter, starting migration in September. Eurasian waxwings typically winter from eastern Britain to northern China and Japan, while North American birds trend southeast, with many wintering in southeast Canada.
In some years, waxwings may irrupt south of their usual wintering areas in large numbers, driven by the availability of fruit.
Breeding habitat includes mature conifers, particularly spruce, and they also feed in open wet areas. After breeding, they occupy various habitats with suitable fruit and roost communally in dense trees during winter.
Bohemian waxwings return from wintering grounds in February or March, with northern breeders arriving at breeding areas by April or early May. These monogamous birds nest from mid-June to July, often in close proximity to one another. Males may defend their mates from rivals, while females can squabble over nest sites. The male’s courtship display includes presenting gifts to the female, though this rarely leads to copulation.
The nest is a cup of twigs lined with softer materials, built 1.3–15 m above the ground in trees. Clutches typically contain 3–7 glossy pale blue eggs, with incubation lasting 13–14 days solely by the female. Chicks are altricial and fed by both parents, primarily worms in the early days, shifting to fruit later. They fledge about 14–16 days post-hatching and are supported by the adults for two weeks afterward.
Breeding densities are generally low, around ten birds per square kilometer, with one brood annually. Lifespans can exceed 13 years in Europe, but factors like predation and collisions contribute to mortality.
Waxwings primarily eat fruit in winter and insects during the breeding season. They catch insects, like mosquitoes and midges, by flycatching from perches or picking them off vegetation. Their diet includes various berries such as rowan, vaccinium, and rubus, ingesting hundreds of berries daily, sometimes exceeding their weight. A single waxwing was noted to consume 600 to 1,000 cotoneaster berries in six hours. Foraging in large flocks helps them evade competition from other birds, like mistle thrushes.
Their fruit-rich diet is high in sugar but low in nutrients, necessitating large consumption. Bohemian waxwings have a large liver to efficiently convert sugar to energy, and they can metabolize ethanol from fermented fruits. In winter, they drink water or eat snow to counteract dehydration. Historically, their arrival was linked to cholera and plague epidemics, earning them the Dutch name “Pestvogel,” or “plague bird,” as juniper berries were thought to offer protection.
Waxwings are preyed upon by various birds of prey, such as rough-legged buzzards, Eurasian sparrowhawks, and merlins. When alarmed, Bohemian waxwings “freeze” with their bills and necks pointed up, and if this fails, they fly away calling noisily. They are not brood parasitized by species like the common cuckoo, as the cuckoo’s young can’t survive on a fruit diet. Although they reject other birds’ eggs placed in their nests, evidence suggests their ancestors may have hosted parasitic species millions of years ago. Parasitic mites identified on them include Syringophiloidus bombycillae and Ptilonyssus bombycillae. They may also carry blood parasites like Trypanosoma, with low levels of worm infestations.
