Anting is a peculiar behavior observed in many bird species, involving the rubbing of insects, most commonly ants, onto their feathers and skin. This practice serves as part of a bird’s self-care. While not fully understood, it represents an intriguing interaction between birds and their environment.
Describing the Behavior
Birds engage in anting through two methods: active anting and passive anting. In active anting, a bird picks up an ant or a cluster of ants in its beak, then deliberately rubs the insect over its plumage. This often targets specific areas, such as wing and tail feathers, sometimes involving contorted postures as the bird manipulates the ant. After rubbing, the bird may consume the ant or discard it.
Passive anting involves the bird positioning itself directly on an ant nest, allowing ants to crawl freely over its body and feathers. The bird might spread its wings and tail, settling into the ant-laden area, sometimes appearing to perform movements similar to dust bathing. During this process, the bird may shake its head to deter ants from its eyes or mouth. Both methods are intentional, indicating a specific purpose.
Unraveling the Reasons
Hypotheses for anting revolve around the chemical secretions of ants, particularly formic acid. Ants release formic acid as a defense mechanism. Birds seem to utilize this chemical, which is known for its antiseptic and insecticidal properties.
One theory suggests anting controls parasites, as formic acid acts as a natural pesticide or repellent against ectoparasites like mites and lice. While direct evidence of its effectiveness on wild birds is still being researched, it has shown to inhibit feather-damaging bacteria and fungi. This chemical application might also irritate existing parasites, causing them to move to more accessible areas where the bird can then more easily remove them through preening.
Another hypothesis suggests anting aids feather conditioning. Formic acid may help remove old preen oil, which is secreted by the bird’s uropygial gland to keep feathers waterproof and flexible. Anting is frequently observed during late summer and early fall, a period when many birds are molting, suggesting it might soothe skin irritation from new feather growth. Some observations also suggest that anting could be a form of self-stimulation, as birds engaging in the behavior can appear excited or enter a trance-like state.
Common Anting Species
Anting is observed in over 200 bird species worldwide. Many passerine birds, also known as perching birds, engage in anting. Species like American robins, blue jays, European starlings, and various thrushes are frequently noted for this behavior. Crows and blackbirds also commonly exhibit anting. While common among these groups, the specific practice and frequency can vary between bird families and within species.