![Bohemian Waxwing (Bombycilla garrulus) 02](https://upload.wikimedia.org/wikipedia/commons/0/08/Bohemian_Waxwing_%28Bombycilla_garrulus%29_02.jpg)
The Bohemian waxwing (''Bombycilla garrulus'') is a
starling
Starlings are small to medium-sized passerine birds in the family Sturnidae. The Sturnidae are named for the genus ''Sturnus'', which in turn comes from the Latin word for starling, ''sturnus''. Many Asian species, particularly the larger ones, ...
-sized
passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...
bird that breeds in the northern forests of the
Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Sibe ...
and North America. It has mainly buff-grey
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
, black face markings and a pointed crest. Its wings are patterned with white and bright yellow, and some feather tips have the red waxy appearance that give this species its English name. The three subspecies show only minor differences in appearance. Females are similar to males, although young birds are less well-marked and have few or no waxy wingtips. Although the Bohemian waxwing's range overlaps those of the
cedar
Cedar may refer to:
Trees and plants
*''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae
*Cedar (plant), a list of trees and plants known as cedar
Places United States
* Cedar, Arizona
* ...
and
Japanese waxwing
The Japanese waxwing (''Bombycilla japonica'') is a fairly small passerine bird of the waxwing family found in the East Palaearctic. It feeds mainly on fruit and berries but also eats insects during the summer. The nest is a cup of twigs lined wi ...
s, it is easily distinguished from them by size and plumage differences.
The breeding habitat is
coniferous
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All extant ...
forests, usually near water. The pair build a lined cup-shaped nest in a tree or bush, often close to the trunk. The
clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
of 3–7 eggs is
incubated by the female alone for 13–14 days to hatching. The chicks are
altricial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
and naked, and are fed by both parents, initially mostly with insects, but thereafter mainly fruit. They
fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight.
This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...
about 14–16 days after leaving the egg. Many birds desert their nesting range in winter and
migrate
Migration, migratory, or migrate may refer to: Human migration
* Human migration, physical movement by humans from one region to another
** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
farther south. In some years, large numbers of Bohemian waxwings
irrupt well beyond their normal winter range in search of the fruit that makes up most of their diet.
Waxwings can be very tame in winter, entering towns and gardens in search of food,
rowan
The rowans ( or ) or mountain-ashes are shrubs or trees in the genus ''Sorbus
''Sorbus'' is a genus of over 100 species of trees and shrubs in the rose family, Rosaceae. Species of ''Sorbus'' (''s.l.'') are commonly known as whitebeam, r ...
berries being a particular favourite. They can
metabolise
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
alcohol produced in fermenting fruit, but can still become intoxicated, sometimes fatally. Other hazards include predation by
birds of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators ...
, infestation by parasites and collisions with cars or windows. The Bohemian waxwing's high numbers and very large breeding area mean that it is classified as being of
least concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
by the
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
.
Taxonomy
The
waxwing
The waxwings are three species of passerine birds classified in the genus ''Bombycilla''. They are pinkish-brown and pale grey with distinctive smooth plumage in which many body feathers are not individually visible, a black and white eyestripe, ...
s are a family, Bombycillidae, of short-tailed stocky birds with soft plumage, a head crest and distinctively patterned wings and tails. There are three species, the Bohemian, cedar, and Japanese waxwings.
DNA studies and shared features such as a relatively large size, grey underparts and similar undertail patterns suggest that the Japanese and Bohemian waxwings are most closely related within the genus. Although only the cedar and Bohemian waxwings normally have red tips on their wing feathers, this feature is occasionally shown by the Japanese waxwing, suggesting that this was originally a whole-family characteristic that has been lost in one species, rather than an indicator of a close relationship.
DNA analysis
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...
confirms that the cedar waxwing diverged early from the other members of the family. Outside the genus, the closest relatives of the waxwings are believed to be the
silky-flycatcher
The silky-flycatchers are a small family, Ptiliogonatidae, of passerine birds. The family contains only four species in three genera. They were formerly lumped with waxwings and hypocolius in the family Bombycillidae, and they are listed in tha ...
s, the
palmchat
The palmchat (''Dulus dominicus'') is a small, long-tailed passerine bird, the only species in the genus ''Dulus'' and the family Dulidae endemic to the Caribbean island of Hispaniola (split between the Dominican Republic and Haiti). It is rela ...
, and the
grey hypocolius
The grey hypocolius or simply hypocolius (''Hypocolius ampelinus'') is a small passerine bird species. It is the sole member of the genus ''Hypocolius'' and it is placed in a family of its own, the Hypocoliidae. This slender and long tailed bird i ...
, all of which have sometimes been included in the Bombycillidae.
The Bohemian waxwing was described by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in his 1758
10th edition of ''Systema Naturae'' as ''Lanius Garrulus''.
[Linnaeus (1758]
p. 95.
/ref> The waxwings were moved to their own genus, ''Bombycilla'', by Louis Jean Pierre Vieillot
Louis Pierre Vieillot (10 May 1748, Yvetot – 24 August 1830, Sotteville-lès-Rouen) was a French ornithologist.
Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collecte ...
in 1808. The genus name ''Bombycilla'' comes from the Greek ''bombux'', "silk" and the Modern Latin
New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...
''cilla'', "tail";[Jobling (2010) p. 74.] this is a direct translation of the German ''Seidenschwanz'', "silk-tail", and refers to the silky-soft plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
of the bird.[ The species name ''garrulus'' is the Latin for ''talkative'' and was applied to this bird, as "Garrulus Bohemicus", by ]Conrad Gessner
Conrad Gessner (; la, Conradus Gesnerus 26 March 1516 – 13 December 1565) was a Swiss physician, naturalist, bibliographer, and philologist. Born into a poor family in Zürich, Switzerland, his father and teachers quickly realised his tale ...
in 1555;[Jobling (2010) p. 171.][Gessner (1555]
p. 27.
/ref> the term is a reference to a supposed likeness to the Eurasian jay
The Eurasian jay (''Garrulus glandarius'') is a species of passerine bird in the crow family Corvidae. It has pinkish brown plumage with a black stripe on each side of a whitish throat, a bright blue panel on the upper wing and a black tail. The ...
(''Garrulus glandarius'') rather than to the waxwing's vocalisations. The English name "waxwing" refers to the bright red tips of the secondary feathers
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...
on its wings, which look like drops of sealing wax
Sealing wax is a wax material of a seal which, after melting, hardens quickly (to paper, parchment, ribbons and wire, and other material) forming a bond that is difficult to separate without noticeable tampering. Wax is used to verify something su ...
, while "Bohemian" follows Gessner's usage, and may refer to the Romani
Romani may refer to:
Ethnicities
* Romani people, an ethnic group of Northern Indian origin, living dispersed in Europe, the Americas and Asia
** Romani genocide, under Nazi rule
* Romani language, any of several Indo-Aryan languages of the Roma ...
, alluding to the bird's wanderings,[Holloway (2003) p. 39.] or to its presumed origin from Bohemia
Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...
.[Cocker & Mabey (2005) pp. 326–327.] "Waxwing" and "Bohemian waxwing" were first recorded in 1817, the former as a reference to Vieillot's separation of this bird from the "chatterers".
There are three recognised subspecies:[ ]
*''B. g. garrulus'' (Linnaeus, 1758): the nominate subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
, breeds in northern Europe from northern Norway east to the Ural Mountains
The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
.
*''B. g. centralasiae'' ( Poliakov, 1915): breeds from the Urals eastwards across northern Asia.
*''B. g. pallidiceps'' (Reichenow
Anton Reichenow (1 August 1847 in Charlottenburg – 6 July 1941 in Hamburg) was a German ornithologist and herpetologist.
Reichenow was the son-in-law of Jean Cabanis, and worked at the Natural History Museum of Berlin from 1874 to 1921. He was ...
, 1908): breeds in northwestern North America.
The differences between these forms are small and clinal, and the species could be possibly considered as monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
.[ The ]fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
record includes Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
deposits from the UK and the Carpathian Mountains
The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretches ...
.[Főzy & Szente (2013) p. 395.]
Description
The Bohemian waxwing is a starling-sized bird in length with a wingspan, and an average weight of .[ It is short-tailed, mainly brownish-grey, and has a conspicuous crest on its head. The male of the nominate subspecies has a black mask through the eye and a black throat. There is a white streak behind the bill and a white curve below the eye. The lower belly is a rich chestnut colour and there are cinnamon-coloured areas around the mask. The rump is grey and the tail ends in a bright yellow band with a broad black border above it. The wings are very distinctive; the ]flight feather
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...
s are black and the primaries
Primary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the c ...
have markings that produce a yellow stripe and white "fishhooks" on the closed wing. The adult's secondaries end in long red appendages with the sealing wax
Sealing wax is a wax material of a seal which, after melting, hardens quickly (to paper, parchment, ribbons and wire, and other material) forming a bond that is difficult to separate without noticeable tampering. Wax is used to verify something su ...
appearance that gives the bird its English name. The eyes are dark brown, the bill is mainly black, and the legs are dark grey or black.[ In flight, the waxwing's large flocks, long wings and short tail give some resemblance to the ]common starling
The common starling or European starling (''Sturnus vulgaris''), also known simply as the starling in Great Britain and Ireland, is a medium-sized passerine bird in the starling family, Sturnidae. It is about long and has glossy black plumage ...
, and its flight is similarly fast and direct.[ It clambers easily through bushes and trees but only shuffles on the ground.][
The soft, dense feathers are kept in good condition by ]preening
Preening is a found in birds that involves the use of the beak to position feathers, interlock feather that have become separated, clean plumage, and keep ectoparasites in check. Feathers contribute significantly to a bird's insulation, waterp ...
.[ The red waxy tips are the extended and flattened ends of feather shafts, pigmented with ]astaxanthin
Astaxanthin is a keto- carotenoid within a group of chemical compounds known as terpenes. Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-soluble pigment with r ...
and enclosed in a transparent sheath. A study of the cedar waxwings showed that the red tips are few or absent until the third year of life for that related species. All adult waxwings have a complete moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
annually between August and January. Juveniles moult at the same time but retain their flight and some other wing feathers.[
The female Bohemian waxwing is very similar to the male, but has a narrower yellow terminal band to the tail, a less defined lower edge to the black throat and slightly less distinctive wing markings. Juveniles are duller than adults, with whiter underparts, only a few red wing tips, no black on the throat and a smaller black face mask. Compared to the nominate subspecies, eastern ''B. g. centralasiae'' is paler, greyer and has little reddish-brown behind the bill. The American subspecies ''B. g. pallidiceps'' has more colouring on the cheeks and forehead than the nominate form and is otherwise generally duller in appearance.][
The range of the Bohemian waxwing overlaps those of both the other members of the genus. The cedar waxwing is smaller than the Bohemian; it has browner upperparts, a white undertail and a white line above the black eye patch. Adult cedar waxwings have a yellowish belly, and all ages have less strongly patterned wings than the Bohemian waxwing.][Snow & Perrins (1998) pp. 1113–1115.] The Japanese waxwing is easily distinguished from its relatives; it has a red terminal band to the tail, the black mask extends up the rear of the crest, and there is no yellow stripe or red tips on the wings.[Brazil (2009) p. 312.]
The Bohemian waxwing's call is a high trill
TRILL (Transparent Interconnection of Lots of Links) is an Internet Standard implemented by devices called TRILL switches. TRILL combines techniques from bridging and routing, and is the application of link-state routing to the VLAN-aware custom ...
''sirrrr''. It is less wavering and lower-pitched than that of the cedar waxwing,[Sibley (2000) p. 423.] and longer and lower-pitched than the call of the Japanese waxwing.[ Other calls are just variants of the main vocalisation; a quieter version is used by chicks to call parents, and courtship calls, also given during nest construction, have a particularly large frequency range.][ Although not a call as such, when a flock takes off or lands, the wings make a distinctive rattling sound that can be heard away.][
]
Distribution and habitat
The Bohemian waxwing has a circumpolar
Circumpolar may refer to:
* Antarctic region
** Antarctic Circle
** the Antarctic Circumpolar Current
** Subantarctic
** List of Antarctic and subantarctic islands
** Antarctic Convergence
** Antarctic Circumpolar Wave
** Antarctic Ocean
* Arctic ...
distribution, breeding in northern regions of Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
and North America. In Eurasia, its northern nesting limit is just short of the treeline
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...
, roughly at the 10 °C July isotherm, and it breeds south locally to about 51°N.[ Most birds breed between 60–67°N, reaching 70°N in Scandinavia.][ The North American subspecies breeds in the northwestern and north central areas of the continent, its range extending southwards beyond the US border in the ]Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
.[
This waxwing is migratory with much of the breeding range abandoned as the birds move south for the winter. Migration starts in September in the north of the range, a month or so later farther south. Eurasian birds normally winter from eastern Britain through northern parts of western and central Europe, Ukraine, Kazakhstan and northern China to Japan. North American breeders have a more southeasterly trend, many birds wintering in southeast Canada, with smaller numbers in the north central and northeastern US states. Birds do not usually return to the same wintering sites in successive years.][ One bird wintering in the Ukraine was found to the east in ]Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
in the following year.[Newton (2010) p. 406.]
In some years, this waxwing irrupts south of its normal wintering areas, sometimes in huge numbers. The fruit on which the birds depend in winter varies in abundance from year to year, and in poor years, particularly those following a good crop the previous year, the flocks move farther south until they reach adequate supplies.[Newton (2010) pp. 393–395.] They will stay until the food runs out and move on again.[Newton (2010) p. 403.] In what may be the largest ever irruption in Europe, in the winter of 2004–2005, more than half a million waxwings were recorded in Germany alone. This invasion followed an unusually warm, dry breeding season. In 1908, an American flock wide was noted as taking two to three minutes to fly over.[
The breeding habitat is mature conifers, often ]spruce
A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...
although other conifers and broadleaf trees may also be present. More open, wet areas such as lakes and peat swamps with dead and drowned trees are used for feeding on insects. Lowlands, valleys and uplands are used in Eurasia, although mountains tend to be avoided. However, the North American subspecies nests in Canada at altitudes between .[Campbell (1997) p. 466.] Outside the breeding season, the waxwing will occupy a wide range of habitats as long as suitable fruits such as rowan
The rowans ( or ) or mountain-ashes are shrubs or trees in the genus ''Sorbus
''Sorbus'' is a genus of over 100 species of trees and shrubs in the rose family, Rosaceae. Species of ''Sorbus'' (''s.l.'') are commonly known as whitebeam, r ...
are available. It may be found by roads, in parks and gardens or along hedges or woodlands edges. It shows little fear of humans at this time.[ In winter, waxwings roost communally in dense trees or hedges, sometimes with ]American robin
The American robin (''Turdus migratorius'') is a migratory bird of the true thrush genus and Turdidae, the wider thrush family. It is named after the European robin because of its reddish-orange breast, though the two species are not closel ...
s, fieldfare
The fieldfare (''Turdus pilaris'') is a member of the thrush family Turdidae. It breeds in woodland and scrub in northern Europe and across the Palearctic. It is strongly migratory, with many northern birds moving south during the winter. It ...
s or other wintering species.
Behaviour
Breeding
Bohemian waxwings start their return from the wintering grounds in February or March, but northern breeders do not reach their breeding areas until April or early May. This monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
species nests mainly from mid-June to July.[
Waxwings are not highly territorial, and, although normally solitary breeders, several pairs may nest close together where there are a number of good nest sites.][ Males may sometimes deter rivals from approaching their mates, and females may squabble over nest sites. Aggression is shown by sleeking down the feathers and crest, showing the black throat, and opening the bill. The breeding display is almost the opposite of this; the male erects his body and crest feathers, and turns his head away from the female. The male may repeatedly present a gift of a small item, often food, to his partner, placing it in her open bill. In about 90% of cases, this display does not lead to copulation.] Older males have more red tips to the wings and are preferred by females.[
]
The nest, built by both sexes, is a cup of thin twigs lined with softer material such as fine grass, moss, fur or lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.[pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...]
or scrub, commonly close to the trunk. The eggs are a glossy pale blue spotted with black and grey and the clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
is 3–7 eggs, although five or six is most common.[ The average size of the egg is , and it weighs , of which 5% is shell. The eggs are incubated for 13–14 days by the female alone.] She is fed regurgitated berries by her mate, and rarely leaves the nest. The chicks are altricial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
and naked, and have bright red mouths; they are fed by both parents, although the male brings most of the food, mainly insects, in the first few days. The young are subsequently fed largely with fruit. The chicks fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight.
This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...
about 14–16 days after hatching.[ They are fed by the adults for about two weeks after fledging.][
Breeding densities of this waxwing are typically low compared to other passerines, usually less than ten birds per square kilometre (26 per square mile) even in good habitat, although up to 35·6 birds per square kilometre (92 per square mile) have been found in Russia.][ One brood each year is normal.][ Maximum recorded ages are 5 years 10 months in North America and more than 13 years 6 months in Europe.] The average life expectancy is unknown.[ Significant causes of death include predation,][ collisions with windows and cars,][ and poisoning by road salt consumed when drinking.]
Feeding
Waxwings are primarily fruit eaters, but also consume insects during the breeding season. Mosquito
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...
es and midge
A midge is any small fly, including species in several families of non-mosquito Nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some mid ...
s are the most common prey, but many other insects and some spiders are eaten. They are caught mainly by flycatching from an open perch, but some may be picked off vegetation.[ Fruit is normally picked from trees, sometimes from the ground, and is usually swallowed whole. In the summer, '']Vaccinium
''Vaccinium'' is a common and widespread genus of shrubs or dwarf shrubs in the heath family (Ericaceae). The fruits of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry (whort ...
'' and ''Rubus
''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, with over 1,350 species.
Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of these ...
'' species and Canada buffaloberry
''Shepherdia canadensis'', commonly called Canada buffaloberry, russet buffaloberry, soopolallie, soapberry, or foamberry (Ktunaxa: ',) is one of a small number of shrubs of the genus ''Shepherdia'' that bears edible berries.
Description
The pla ...
are important items of their diet, while cotoneaster
''Cotoneaster'' is a genus of flowering plants in the rose family, Rosaceae, native to the Palaearctic region (temperate Asia, Europe, north Africa), with a strong concentration of diversity in the genus in the mountains of southwestern China an ...
, juniper
Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...
, haws, rose hip
The rose hip or rosehip, also called rose haw and rose hep, is the accessory fruit of the various species of rose plant. It is typically red to orange, but ranges from dark purple to black in some species. Rose hips begin to form after pollinat ...
s and apples predominate outside the breeding season. Rowan berries are a favourite food, and are eaten whenever available.[
Waxwings can eat huge numbers of berries, each bird sometimes consuming several hundred a day, more than double its own weight. One individual was recorded as eating between 600 and 1,000 cotoneaster berries in six hours, and defecating every four minutes.][ Waxwings travel significant distances when feeding and help to disperse the fruit seeds.][ Waxwings forage in large flocks, sometimes of several hundred birds, which enables them to overwhelm birds such as ]mistle thrush
The mistle thrush (''Turdus viscivorus'') is a bird common to much of Europe, temperate Asia and North Africa. It is a year-round resident in a large part of its range, but northern and eastern populations migrate south for the winter, often ...
es attempting to defend their fruit trees.[Snow & Snow (2010) pp. 154–156.]
Fruit is rich in sugar but deficient in other nutrients, so it must be eaten in large quantities.[ Bohemian waxwings have a large liver which helps to convert sugar to energy. They can ]metabolise
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...
produced from the fermentation of those sugary fruits more efficiently than humans, but may still become intoxicated,[Mullarney ''et al.'' (2009) p. 272.] sometimes fatally.[ Waxwings often drink water or eat snow in winter, since the sugar in their fruit diet tends to dehydrate the birds through an ]osmotic
Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of ...
effect. In the summer, the fruits are juicier and water is less of a problem.[
In the past, the arrival of waxwings sometimes coincided with ]epidemic
An epidemic (from Ancient Greek, Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time.
Epidemics ...
s of cholera
Cholera is an infection of the small intestine by some strains of the bacterium ''Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and ...
or plague
Plague or The Plague may refer to:
Agriculture, fauna, and medicine
*Plague (disease), a disease caused by ''Yersinia pestis''
* An epidemic of infectious disease (medical or agricultural)
* A pandemic caused by such a disease
* A swarm of pes ...
, and led to the old Dutch and Flemish name ''Pestvogel'', "plague bird". The juniper berries
A juniper berry is the female seed cone produced by the various species of junipers. It is not a true berry, but a cone with unusually fleshy and merged scales, which gives it a berry-like appearance. The cones from a handful of species, especial ...
on which they fed were thought to offer protection, and people consumed the fruit and burned branches to fumigate their houses.[
]
Predators and parasites
Waxwings are preyed upon by birds of prey
Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predators ...
including rough-legged buzzard
The rough-legged buzzard or rough-legged hawk (''Buteo lagopus'') is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America, Europe, and Russia during the breeding season and migrates south for the winter. It ...
s, Eurasian sparrowhawk
The Eurasian sparrowhawk (''Accipiter nisus''), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barred ...
s, prairie falcon
The prairie falcon (''Falco mexicanus'') is a medium-large sized falcon of western North America. It is about the size of a peregrine falcon or a crow, with an average length of 40 cm (16 in), wingspan of approximately 1 meter (40&nb ...
s, and great grey shrike
The great grey shrike (''Lanius excubitor'') is a large and predatory songbird species in the shrike family (Laniidae). It forms a superspecies with its parapatric southern relatives, the Iberian grey shrike (''L. meridionalis''), the Chinese ...
s. Merlins attack winter flocks, including those in cities.[Semenchuk (1992) p. 91.] When alarmed, Bohemian waxwings "freeze" with bill and neck pointing upwards. If this fails, they fly, calling noisily.[
Bohemian waxwings are not brood parasitised by the ]common cuckoo
The common cuckoo (''Cuculus canorus'') is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals.
This species is a widespread summer migrant to Europe and Asia, and winters in Africa. I ...
or its relatives in Eurasia because the cuckoo's young cannot survive on a largely fruit diet. In North America, the waxwing's breeding range has little overlap with brown-headed cowbird
The brown-headed cowbird (''Molothrus ater'') is a small, obligate brood parasitic icterid native to temperate and subtropical North America. It is a permanent resident in the southern parts of its range; northern birds migrate to the southern ...
, another parasitic species. Nevertheless, eggs of other birds placed in a Bohemian waxwing's nest are always rejected. This suggests that in the past, perhaps 3 million years ago, the ancestral waxwing was a host of a brood parasitic species, and retains the rejection behaviour acquired then.
Parasitic mite
Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...
s include ''Syringophiloidus bombycillae'', first identified on this species, and the nasal mite ''Ptilonyssus bombycillae''. Blood parasites include ''Trypanosoma
''Trypanosoma'' is a genus of kinetoplastids (class Trypanosomatidae), a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek ''trypano-'' (bore ...
'' species, and a ''Leucocytozoon
''Leucocytozoon '' (or ''Leukocytozoon'') is a genus of parasitic alveolates belonging to the phylum Apicomplexa (which also includes the malaria parasites).
The species of this genus use either blackflies ('' Simulium'' species) or a biting mi ...
'' first identified in this waxwing. Bohemian waxwings may carry flatworms
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegment ...
and tapeworms
Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of man ...
, but levels of parasitic worm
Parasitic worms, also known as helminths, are large Parasitism#Basic concepts, macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted helminth, soil-transmitted and intestinal parasit ...
infestation are generally low.[Rausch (1983) p. 401.]
Status
The global population of the Bohemian waxwing has been estimated at more than three million birds, and the breeding range covers about 12.8 million km2 (4.9 million mi2). Although this species' population, as of 2013, appears to be declining, the decrease is not rapid nor large enough to trigger conservation vulnerability criteria. Given its high numbers and huge breeding area, this waxwing is therefore classified by the International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
as being of least concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
. The woodlands used by this species are well to the north of major human populations, and the birds can use disturbed habitats, so there are no serious long-term threats to this species.[
]
Gallery
File:Bombycilla garrulus MWNH 1285.JPG, Egg, Collection Museum Wiesbaden
The Museum Wiesbaden is a two-branch museum of art and natural history in the Hessian capital of Wiesbaden, Germany. It is one of the three Hessian State museums, in addition to the museums in Kassel and Darmstadt.
History
The foundation of ...
File:Bohemian Wax Wing.jpg, alt=waxwing eating berries, Feeding on rowan
Notes
References
Cited texts
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* Rausch, Robert L. "Biology of Avian Parasites: Helminthes" in
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External links
*
Bohemian waxwing Species Account
– Cornell Lab of Ornithology
*
{{Taxonbar , from=Q26135
Bohemian waxwing
The Bohemian waxwing (''Bombycilla garrulus'') is a starling-sized passerine bird that breeds in the northern forests of the Palearctic and North America. It has mainly buff-grey plumage, black face markings and a pointed crest. Its wings are ...
Holarctic birds
Bohemian waxwing
The Bohemian waxwing (''Bombycilla garrulus'') is a starling-sized passerine bird that breeds in the northern forests of the Palearctic and North America. It has mainly buff-grey plumage, black face markings and a pointed crest. Its wings are ...
Taxa named by Carl Linnaeus