Birds consume a wide array of food sources. While many associate bird diets with seeds, fruits, or larger insects, ants are a notable and often surprising dietary component for numerous species. This highlights the specialized adaptations birds have developed to utilize these abundant social insects, revealing more about their foraging strategies and nutritional needs.
Common Ant-Eating Bird Species
Many bird species regularly include ants in their diets, ranging from common backyard birds to specialized foragers. Woodpeckers, as a group, consume more ants than most other birds, with ants sometimes making up over 50% of their diet. Northern Flickers, a type of woodpecker, are particularly fond of ants, which can constitute around 45% of their food intake, and have been observed ingesting over 5,000 ants in a single feeding. Pileated Woodpeckers also frequently eat carpenter ants, which can account for up to 60% of their diet.
Beyond woodpeckers, various other birds regularly eat ants. These include pigeons, pheasants, sparrows, starlings, hummingbirds, crows, wild turkeys, and wrens. Swallows, like Barn Swallows and Tree Swallows, and swifts are known to catch flying ants during their nuptial flights, demonstrating aerial foraging adaptations.
Nutritional Value of Ants for Birds
Ants provide birds with important nutritional benefits. They are a protein-rich food, supplying essential nutrients that contribute to muscle strength and the ability to fly. Beyond protein, ants also contain zinc, iron, and potassium, supporting functions like oxygen circulation in the blood and maintaining a regular heartbeat.
While ants produce formic acid as a defense mechanism, birds typically tolerate or even benefit from this compound. For some birds, especially during breeding or migration, the high protein and fat content of ants, particularly winged ants (alates), can be especially beneficial. These alates provide a concentrated energy source, supporting the high energetic demands of both adult birds and their nestlings during these periods.
Anting: A Specialized Behavior
“Anting” is a distinctive behavior where birds apply ants, often live ones, to their feathers and skin. This behavior is different from eating ants, although some birds may consume the ants afterward. Over 200 species worldwide have been observed anting.
There are two main forms of anting: active and passive. Active anting involves a bird picking up an ant in its beak, sometimes crushing it, and then rubbing it over its feathers, particularly on the wings and tail. Passive anting occurs when a bird lies down on an anthill or an area with many ants, spreading its wings and tail to allow the ants to crawl freely through its plumage. Birds typically choose ants that produce formic acid for anting.
The precise reasons for anting are not fully understood, but several theories exist. One hypothesis suggests that the formic acid and other chemicals secreted by ants act as a natural pesticide, helping birds control feather mites, lice, and other parasites. Another theory proposes that anting helps soothe irritated skin, especially during molting when new feathers are emerging. Some research also suggests anting might be a way for birds to make ants more palatable by inducing them to release their defensive formic acid before consumption.
Foraging Methods for Ants
Birds employ various strategies to locate and consume ants, adapted to the ants’ habitats and the birds’ own physical characteristics. Many birds forage for ants on the ground, pecking at individual ants or digging into the soil to access ant colonies. Woodpeckers, such as Northern Flickers, use their long, sticky tongues to lap up hundreds of ants at once from the ground or from within trees.
Some species, like the Rufous Woodpecker, have a unique relationship with ants, even nesting inside ant colonies. Arboreal foragers pick ants directly off tree trunks and leaves. When winged ants undergo their nuptial flights, birds like swallows, swifts, and even hummingbirds engage in aerial pursuit, catching these flying insects mid-air.