For years, researchers have been attempting to explore the reasoning behind the act of anting among Jays and other species of birds.
The Blue Jay may be one of the most recognizable birds in North America, particularly here in Ontario, where they are so common; our nation’s only professional baseball team is named after them. While these birds are awfully common in our neck of the woods, few concrete details are present about why they participate in an activity referred to as anting.
This somewhat comical behaviour occurs when certain species of birds engage in the act of either rubbing ants along their feathers or allowing ants to crawl over their bodies. Obviously, different species do this in different ways. Blue Jays, for example, will actively physically hold ants in their beaks and rub them through their feathers, while Wild Turkeys, on the other hand, will crouch atop an anthill and allow ants to craw freely through their feathers.
While the act of anting is a seemingly simple behaviour, the actual function of the activity has been debated and studied for years. There are two main schools of thought, or hypothesis on the behaviour. The first belief is that birds use the insects as a feather maintenance tool or for comfort, as many observed instances of the behaviour have been noted in the late summer and fall. During this time of the year, many avian species go through a molting period and researchers believe that anting could provide relief to birds during this feather replenishment phase.
The other and most common belief is that birds utilize the formic acid solution secreted by ants as a defense mechanism to protect themselves from lice and mites. This being said, many laboratory studies have proven that the acid solution emitted by ants is in fact strong enough to kill lice and mites, there are no conclusive studies indicating the acid kills lice and mites on wild birds.
More recently, one other hypothesis was presented when researchers from the Department of Neurobiology and Behavior and Department of Biological and Environmental Engineering at Cornell University. Thomas Eisner and Daniel Aneshansley presented six hand-reared blue jays with two varieties of ants: one that had their formic acid-containing sac removed and a group of ants that were still equipped with the sac.
The ants which were not equipped with the formic acid were eaten immediately by the jays while 61% of the ants with the acid intact were used for anting. Concluding that there was something the jays definitely associated with the formic acid contained in the ants and that perhaps prey preparation had everything to do with this acute behaviour.
Proponents of this theory believe that birds will hold the insect in their beak by their thorax and pass them through their feathers, thus engaging the defense mechanism within the ant, utilizing their feathers as some sort of napkin to get rid of the acid before swallowing the insect.