By Linda Fine Hunt
At the top of my driveway stands a mountain ash tree. In the fall, clusters of bright red berries decorate its branches, and flocks of waxwings feast on these berries. Born in St. Louis, Missouri, I never saw Bohemian or Cedar Waxwings until I moved to Montana. Waxwings caught my attention because they remind me of female Northern Cardinals, birds I miss. At first, I didn’t realize I was observing two different species of birds in the same flock. Cedar Waxwings are smaller, browner, and less vibrantly marked than their Bohemian counterparts. The rarer species is the Bohemian Waxwing, scientifically known as Bombycilla garrulus.
Bohemian Waxwings are named for their wandering behavior. Outside of the breeding season, they move from place to place in search of the next patch of fruit trees to raid. Like a starling bird in size, they are adorned with a distinctive crest and a striking plumage of buff-grey. Their black facial markings and pointed crest are complemented by wings patterned with white and bright yellow. The tips of some wing feathers are a vivid red, reminiscent of sealing wax, which is the origin of the bird’s common name. Both sexes are similar in appearance, with the females slightly less marked.
These birds breed in the northern forests of North America. Bohemian Waxwings are known for their irruptive southern migrations in search of fruit during winter. They roost communally in dense trees or hedges, sometimes alongside other wintering species.
Christmas bird census records in Winnipeg, Canada, have shown as many as 4,724 in 1989 to as few as one bird in 1992! Over time, the Bohemian Waxwing population increased due to ornamental plantings of fruit trees such as crabapples and mountain ash. Both provide the birds with a feast of fruit. Bohemian Waxwings now enjoy a large population and an extensive breeding range. They face no significant long-term threats, and they know how to utilize disturbed habitats.
Bohemian Waxwings possess intestinal enzymes that catalyze sucrose (sugar). Their intestines are twice as wide as those of other birds and are relatively short. This allows them to digest large volumes of fruit efficiently. When fruit and berries are scarce, they supplement their diet with insects, flower buds, and tree sap. Interestingly, all waxwings can metabolize ethanol, making them susceptible to intoxication from consuming too much fermented fruit. They may sometimes gorge themselves on sugary fruit to the point where they cannot fly. In such cases, they might lie motionless beneath a crabapple tree. They usually recover after a few hours of rest. If you encounter a waxwing that appears to be sleeping on the ground, leave the bird alone in a safe and quiet area with access to fresh water.
A 1974 study in Manitoba documented instances of Bohemian Waxwings dying after flying into buildings due to intoxication from eating fermented crabapples. The study concluded the birds had an alcohol content of nearly 3% and blood alcohol of 73 milligrams per 100 milliliters. For humans, that would be above the limit for driving, let alone flying!
Bohemian Waxwings form monogamous pairs. They nest during July and August, when fruits and berries are available to feed their young. They construct their nest as a cup made from grass, weeds, and plant fibers lined with fine grasses and animal hair. A typical clutch consists of four-to-six pale blue spotted eggs. The female incubates the eggs for 13 to 14 days. The chicks hatch in an altricial state, meaning they are naked, dependent on their parents, and have their eyes closed at birth. Both parents are responsible for feeding the chicks, which fledge approximately 14 to 16 days after hatching. After fledging, the young birds are cared for by their parents for an additional two weeks.
Seeing tufted heads of Bohemian Waxwings inspired me to learn more about these birds because they resembled my hometown’s favorite baseball bird. Maybe Northern Cardinals will discover Montana. Meanwhile, let’s plant more mountain ash and crabapple trees. They add beauty year-round and support the survival of both Bohemian and Cedar Waxwings during their migration through Montana.