Anting in Wild Birds, Its Frequency and Probable Purpose

Abstract

A major problem facing anyone investigating anting behavior in wild birds is scarcity of detailed published accounts. Brackbill (1948) lists 13 records from Maryland, all between mid-May and end of August, and notes that the behavior patterns of anting and sunning appear to be complementary. Groskin (1950) adds 13 records from Pennsylvania, all between mid-May and end of first week in October, and expresses opinion, which I share, that anting in wild is more common than published records indicate because many bird-watchers are prone to mistake motions for ordinary preening. Two important studies present opposing views on purpose of anting in avian behavior. After nearly 3 years of experiments with a captive Orchard Oriole (Icterus spurius), Whitaker (1957) concludes that bird appeared to derive sensual pleasure, possibly including sexual stimulation, from anting. Simmons (1966), after reviewing at length work of Mrs. Whitaker and others, states: True anting is strictly functional and probably belongs to feather-maintenance group of behaviour patterns. He considers anting with substitutes, however, to be non-functional, arising from developmental 'error' in learning process during ontogeny of anting responses. Calling evidence for self-stimulation tenuous, Simmons concludes that it is highly improbable and contrary to accepted evolutionary thinking that a widespread and stereotyped behaviour pattern such as anting has no function, existing solely for 'pleasure' it gives. Southern (1963) saw three species of birds anting while feeding and bathing on a freshly sprinkled lawn. He collected one of these birds and found it free of parasites but showing early stages of feather growth, which led him to advance theory that birds use excretions of ants to soothe skin irritated by new feather growth. In March 1964 I began systematic studies at Zebulon (about 20 miles east of Raleigh), Wake County, North Carolina, in an attempt to establish a relationship between frequency of anting activity and time of day, season of year, or weather conditions. I believed that a demonstrated peak of anting activity, if clearly related to any of these factors, would be a significant indication of purpose of anting in avian behavior.