barkforaging

Barkforaging, also written as bark foraging, is a foraging strategy in which animals extract food from the bark or the microhabitats beneath it. The term covers eating insects and their larvae living in or under the bark, as well as accessing sap, lichens, fungi, and occasionally exposed cambial tissue. It is observed in a range of taxa, especially birds such as woodpeckers, nuthatches, creepers, and treecreepers, and in some mammal species like squirrels and porcupines.

In birds, bark foraging involves probing crevices, chiseling, peeling bark, and drilling to reach concealed prey. Some species also create sap wells to attract sap-feeding insects, a behavior exemplified by sapsuckers. Mammals may strip or scratch bark to access the underlying phloem or cambium, or to reach arthropods living beneath the bark. Bark-dwelling prey includes beetles and their larvae, ants, spiders, and other invertebrates, as well as fungal fruiting bodies and lichens that contribute non-animal food sources.

Ecological context and dynamics: Bark foraging can influence insect populations and, indirectly, tree health. It tends to vary with prey availability, season, and tree species chemistry. Predator avoidance and energy costs shape when and where bark foraging is most advantageous. The behavior often occurs in forested ecosystems where bark-dwelling prey are abundant, and it can coexist with other foraging strategies by component species.

See also: foraging ecology, sap-sucking, woodpecker foraging, bark beetles.