Bohemian waxwings usually communicate through vocalizations, similar to their close relatives, cedar waxwings. Social calls are described as a trilling "zeee". Hatchlings also use a quiet trill with parents. The basic call is a high pitched, rapid trill that has a variety of frequencies and is generally lower in pitch than that of cedar waxwings When mates are within range of each other contact calls are used. These are normally softer and higher in pitch than the social call. A courtship call consists of a very wide frequency spread. Both mates give courtship calls during nest-building and courtship interaction. Females continue to give courtship calls while feeding and sitting in the nest. A disturbance call is normally characterized by a long descending whistle. The disturbance call is used during nest-building and incubation. No injury or begging calls have been reported in Bohemian waxwings.
Communication Channels: visual ; acoustic
Other Communication Modes: duets ; choruses
Perception Channels: visual ; tactile ; acoustic ; chemical
Bohemian waxwing populations are increasing due to conservation of shrub lands in the United States. Some of the problems facing Bohemian waxwing populations are collisions with windows, automobile collisions, and the toxic effects of pesticides.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of Bohemian waxwings on humans.
Bohemian waxwings are sought after by bird watchers and they provide important ecosystem services by dispersing the seeds of the fruiting trees and shrubs they eat.
Bohemian waxwings are preyed on by falcons and hawks. They are important seed dispersers and prey on small, flying insects. There are 2 types of protozoan parasites documented in Bohemian waxwings: Leucocytozoon and Trypanosoma.
Ecosystem Impact: disperses seeds
Commensal/Parasitic Species:
Bohemian waxwings are frugivorous and insectivorous. The main source of food is sugary fruits. Bohemian waxwings have a large liver which helps convert sugar to energy. They also have the ability to metabolize ethanol from the fermentation of those sugary fruits. Favorite fruits in North America include juniper (Juniperus virginiana) and mountain ash (Sorbus americana). Bohemian waxwings also feed on aerial insects during the summer. In late spring and early summer insects, especially midges (Chironomidae) and mosquitos (Culicidae), make up about 37% of their diet. Insects are also favored during nesting. When preferred food sources are less abundant, they feed on flowers and sap from trees.
Animal Foods: insects
Plant Foods: fruit; flowers; sap or other plant fluids
Primary Diet: carnivore (Insectivore ); herbivore (Frugivore )
Bohemian waxwings are native to the Nearctic and Palearctic regions. Their range during times of breeding in the Nearctic region spans as far west as central Alaska and as far east as the central part of Ontario. Most breeding regions do not extend any farther south than the most southern part of British Columbia. They normally do not breed north of Alaska or Nova Scotia. In March and April, this species migrates south to southwest British Columbia and the northern United States. In the Palearctic region breeding occurs in the northern parts of Eurasia, most commonly in Scandinavia, Russia and Siberia. These populations migrate south to central Europe and east to central Japan in the non-breeding season.
Biogeographic Regions: nearctic (Native ); palearctic (Native )
Other Geographic Terms: holarctic
During the breeding season, Bohemian waxwings are most common in woodlands ranging from coniferous to coniferous-deciduous. This species also inhabits areas around lakes, streams, and swamps. Typically, they inhabit areas where they can forage for fruits and insects in plentiful amounts. During spring and fall migration they abandon woodlands to seek areas high in fruit abundance, including urban habitats. When food resources diminish, they relocate. During winter seasons, Bohemian waxwings are found in woodland or scrub areas with fruit that remains on branches.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: taiga ; forest ; scrub forest
Other Habitat Features: urban ; suburban ; agricultural ; riparian
The longest reported lifespan for a banded bird in North America was 5 years 10 months. This species is recorded living as long as 12 years in Europe. The main causes of mortality are predation, competition between similar species, and failure to fully metabolize ethanol produced from the consumption of fruits (intoxication).
Range lifespan
Status: wild: 12 (high) years.
Bohemian waxwings are described as starling-sized, having sleek crests, gray overall, with face washed in chestnut. The tip of the tail has a yellow band. Adult males have a throat patch that is larger than that of females and a broader yellow tip to the tail. The common name, "waxwing," comes from the red waxy tips on their secondary feathers. A similar species, cedar waxwings (Bombycilla cedrorum), are smaller, having a pale yellow belly, and wings that are not as colorful. Juvenile Bohemian waxwings have plumage that is more gray than that of adults, with a whitish throat, and streaked underparts.
Range mass: 46.5 to 69.0 g.
Range length: 159 to 203 mm.
Range wingspan: 30 to 36 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Bohemian waxwings are preyed on mainly by birds of prey, including merlins (Falco columbarius), which prey extensively on winter flocks, prairie falcons (Falco mexicanus), rough-legged hawks (Buteo lagopus), and Eurasian sparrowhawks (Accipiter nisus). When approached, Bohemian waxwings adopt a cryptic posture with neck and bill extended skyward while they remain very still. If the cryptic posture fails to be effective, they fly upward and chatter loudly to warn other waxwings of a threat.
Known Predators:
Anti-predator Adaptations: cryptic
Bohemian waxwings find mates during winter and spring flocks through courtship feeding behavior and courtship hopping. Courtship feeding and hopping happens when the male and female are perched and they in turn hop toward one another until they are close enough to touch bills. Once they are close, they pass food or other objects back and forth while hopping away and then back toward the mate before returning the object. This exchange can happen several times. It is thought that red wax on the wings is used to attract females. The older, and potentially more experienced, males have the largest amount of waxy substance on the tips of their secondary feathers. Males with more wax are preferred by females.
Mating System: monogamous
Breeding season of Bohemian waxwings occurs at the same time as the ripening of fruit in the summer. This species breeds later than most birds, even later than their close relatives, cedar waxwings (Bombycilla cedrorum). The typical breeding season is between March and April or as late as May to late June. The typical brood consists of 4 to 6 smooth, glossy eggs that are pale blue-gray marked with black dots and wavy lines. Eggs are sub-elliptical to oval and 25 x 17 mm. Hatchlings are naked, with a red mouth with purple bands and a purplish tongue. Fledging time is 15 to 17 days. Young leave the nest barely able to fly, after 18 days. Fledging occurs from mid-June to mid-August, with most fledging in July.
Breeding interval: Breeding occurs once a year, occasionally twice a year if the first breeding attempt is prior to March.
Breeding season: Breeding occurs from March to late June.
Range eggs per season: 4 to 6.
Range time to hatching: 13 to 14 days.
Range fledging age: 15 to 17 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Female Bohemian waxwings incubate their eggs for 14 to 15 days. Although incubation is only completed by females, both females and males feed the young. Males may spend more time feeding the young once they have hatched. Both parents may continue to feed young after fledging for up to two weeks.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
