By Terry W. Johnson
One of the things I enjoy most about watching wildlife in my backyard is that I get watch animals engage in all sorts of activities from the comfort of my home. I can watch them court prospective mates, build nests, raise young, feed and interact with one another -- you name it.
However, there is one activity that has eluded me. It is known as anting, and it's one of the most bizarre and little known behaviors exhibited by birds and even gray squirrels. However, most biologists and wildlife enthusiasts have never witnessed it.
There are two types of anting: active and passive. In active anting, a bird will crush an ant in its bill and smear it on its feathers or skin. Birds are also known to use a number of other things for apparently the same purpose. The vast majority of these substances have a high acid content. These alternatives include such items as coffee, berries, cigarette butts, orange juice, lemons, vinegar, soap suds, mothballs and beer.
Perhaps the strangest case of active anting involved a tame rook in England. This remarkable bird learned to ignite matches. After the flame had died down, it would rub the still hot tip of the match on the undersides of its wings. When passively anting, a bird probes its bill into an ant nest, fluffs out its feathers and then plops down on the mound. The bird allows the ants that swarm out of the nest to crawl all over its body. It is assumed that the ants bite the bird. Apparently, birds don't find these "treatments" uncomfortable and they often appear excited or drunk.
Biologists disagree as to why birds engage in this unusual behavior. Some suggest that birds use the ants to eliminate parasites. However, the most widely held theory is that the birds use ants to soothe irritated skin, much the way we apply lotion to our bodies.
There are many reasons why this last theory is more plausible.
First of all, anting is more common during late summer and early fall. This is when new feathers are being replaced more rapidly than at any other time of the year. During this molting period, many
birds seem to suffer considerable discomfort.
This is also a time when rainfall is typically high. During wet weather, feathers are lost more rapidly than in dry weather. Also, anting is more common in parts of the country, such as the Southeast, where summer rains are common.
Birds that are actively anting will smear ants on feathers and skin where feathers are being replaced. Areas treated often included the flanks, wings, base of the tail and undersides of the wings.
I know what you are probably asking yourself: How do ants help relieve this discomfort?
The best clue to the mystery lies in the fact that only 24 species of ants are known to be used in anting. All 24 contain high levels of formic acid. Formic acid feels hot to the touch and easily penetrates the skin. As such, the acid supposedly soothes the bird's itching skin.
Anting has been documented in more than 200 species of birds worldwide. Many of these birds are backyard residents in Georgia, such as song sparrows, blue jays, northern cardinals, brown thrashers, European starlings, American robins, eastern bluebirds and gray catbirds. Even two of Georgia's favorite game birds, northern bobwhites and wild turkeys, also known to engage in anting.
John James Audubon was the first to record this phenomenon in 1830. The painter reported seeing young turkeys rolling in anthills. Much later, in the 20th Century, two North Carolina housewives provided the world with most of what is known about anting. They made their discoveries by spending hours every day watching the behaviors of birds living in their backyards.
Observations of anting in the wild are far and few between. This is illustrated by the fact that one of these women viewed anting only 48 times in six years! Consequently, most of the current research on this behavior is being conducted in laboratories.
It is obvious that we have much to learn about anting. You can help unravel the mystery swirling around anting by watching the birds in your backyard. If you see a bird that appears to be anting, carefully record what happens. It is possible that you are witnessing something that has never been documented in the wild.
However, this information is valuable only when it is shared with others. If you witness anting, drop me a line at firstname.lastname@example.org. I would be more than happy to share your information with other biologists.
Terry W. Johnson is a former Nongame program manager with the Wildlife Resources Division, a backyard wildlife expert, and executive director of TERN, the friends group of the Nongame Conservation Section. (Permission is required to reprint this column. Contact email@example.com.) Learn more about TERN, The Environmental Resources Network, at http://tern.homestead.com. “Out My Backdoor” columns archive.