(noun) A type of bird that relies on trees and dense foliage, spending much of its life in trees and rarely either descending to the ground or otherwise leaving the cover of the canopy. These birds are found exclusively in forested habitats, though the type of forest may vary widely, from tropical jungles to mountain regions to boreal forests, or even orchards, arboretums, parks or other urban or suburban forests.
Arboreal birds not only perch and roost in trees, they are specialized to forage in trees, nest in trees or tree cavities and otherwise stay in trees almost exclusively. While there is great diversity among arboreal bird species, common characteristics these birds often share include…
- Heavily marked plumage that serves as camouflage in the dappled shade of wooded habitats, though the markings may still be bright colors or can have strong individual marks or patches. Bright plumage will be more visible in shade, making these birds more visible to potential mates or allowing the colors to be used to intimidate intruders.
- Diets adapted to the forest environment, which may be insectivorous or frugivorous. Insectivorous arboreal species may glean insects from bark, branches or leaves, or may hawk flying insects in the canopy. Frugivorous birds, on the other hand, will favor fruit trees for their succulent crops.
- Widespread ranges that cover nearly any forested region on earth, depending on the type of forest required to meet an individual species' needs. Depending on their food preferences, many of these birds migrate or may switch to slightly different diets in the non-breeding season in order to make the most of the trees in their range.
- Feet and talons specially adapted for gripping and climbing trees. Some arboreal birds have specialized toe arrangements that allow them to climb vertically up or down tree trunks or else agilely move through branches, which allows them to make the most of the habitat and adapt to niches other birds may miss.
Because there are many arboreal bird species, some birds have become specially adapted to certain trees, but that specialization comes with a price. If those trees are destroyed or become scarce, the birds that rely on them are less adaptable to rapidly changing their habitat, and could become endangered or extinct. A key example of this specialization is the Kirtland's warbler, which relies on young jack pine habitats, but is at risk because of changing forestry management practices that have altered its habitat to be less suitable. Fortunately, when conservationists recognize that specialization, steps can be taken to protect the birds that rely on certain trees, and in the case of the Kirtland's warbler, new management techniques are being used to benefit both the forest and the birds.
There are many arboreal birds, including nuthatches, creepers, woodpeckers, orioles, barbets, chickadees, tits, kinglets, toucans, warblers, many parrots and the unique hoatzin.
Photo – Eurasian Nuthatch © Craig Nash