The Cedar Waxwing (Bombycilla cedrorum) is a striking, medium-sized bird recognized by its sleek, brown plumage, black face mask, and prominent crest. This species is primarily a frugivore, meaning its annual sustenance is overwhelmingly plant-based, often consisting of 70 to 90 percent berries and other fleshy fruits. This reliance on sugary fruit drives the bird’s nomadic behavior as it follows seasonal availability. Its specialized diet shapes the bird’s life cycle, including its migration patterns and unique nesting schedule.
The Year-Round Reliance on Fruits
Small, soft, high-sugar berries form the defining, year-round component of the Cedar Waxwing’s diet. The bird’s name is derived from its fondness for the waxy “berries” of the eastern red cedar (Juniperus virginiana), a crucial food source during winter months.
In the early summer, waxwings gorge on rapidly ripening fruits, such as serviceberries, mulberries, and strawberries, to fuel their breeding activities. These energy-packed foods are consumed whole due to the waxwing’s wide gape, allowing them to process large quantities quickly.
As summer transitions into fall, the birds target fruits that persist longer on the branch, including those from dogwood, mountain ash, and hawthorn trees. The winter diet relies on overwintered fruits like juniper berries, holly, crabapples, and mistletoe. The bird’s digestive system is highly efficient at processing the pulp and sugars, often passing the seeds intact within a short period. This rapid transit makes the Cedar Waxwing an important disperser of seeds for many native plant species.
The Crucial Role of Insects
While fruits provide the bulk of the Cedar Waxwing’s energy needs, insects and other arthropods become a temporary addition to the diet. This shift is driven by a necessity for protein and fat, nutrients scarce in the carbohydrate-rich fruit diet. During the nesting and breeding season, insect consumption can increase significantly, accounting for up to 20 to 25 percent of their intake in spring and summer.
The high-protein diet is particularly important for the rapid development of nestlings. For the first few days after hatching, young waxwings are fed almost exclusively insects by their parents. This initial insect-heavy diet ensures the young receive the necessary amino acids for muscle and feather growth before they transition to a more fruit-based diet.
The waxwings opportunistically feed on a variety of insects, including caterpillars, leaf beetles, and scale insects gleaned from foliage. They are also adept at catching flying insects, such as dragonflies and mayflies, which they pursue and capture in mid-air.
Unique Foraging and Feeding Behaviors
The Cedar Waxwing exhibits several distinctive behaviors associated with its fruit-focused diet. Since a single plant offers only a temporary food source, they are highly social and forage in large, nomadic flocks that can number in the hundreds. This flock feeding allows them to quickly strip a fruiting tree before moving on to the next available patch.
When feeding on insects, the birds employ “flycatching,” where they sally out from a perch to snatch a flying insect from the air before returning to their original spot. More famously, waxwings engage in a unique social ritual, especially during courtship, by passing a berry or small object along a line of birds from beak to beak.
The waxwing’s appetite for fruit sometimes leads to intoxication, or “drunkenness,” which occurs when they consume overripe berries that have fermented. As temperatures warm in spring, fruits that persisted through winter can begin to ferment, producing ethanol, with some berries reaching alcohol levels of up to 3.8 percent. Consuming large quantities of this naturally alcoholic fruit can cause the birds to become disoriented, leading to uncoordinated flight and temporary impairment.