Pigeons know who is nice
In cities, people who like pigeons are a minority. In a New York City park, I recently saw a young woman on a bench calmly feeding a group of the birds by hand with pigeons pecking and cooing right next to her.
Noting pigeons’ reputation as flying rats, animal behavior researcher Ahmed Belguermi of the University of Paris West Nanterre La Défense and his colleagues have found that birds can tell the difference between people and adjust their behavior accordingly. The team has added to the wealth of literature about pigeon smarts with their study in the journal Animal Cognition.
For the experiments in a downtown Parisian park, the team spread out seeds on two identically-sized patches in an area regularly frequented by 80 to 100 pigeons.
One human feeder, clad in a long coat, always acted grouchy and performed “vigorous arm waving” once a minute. This “hostile” behavior at one seed patch kept the pigeons from feeding. In contrast, the “neutral” feeder, also in a long coat of a different color, stood still next to the seeds on the other patch. With a video camera, the scientists captured the number of pigeons feeding on each seeded area.
Then, in testing sessions, the pigeons were allowed to feed on both patches and neither feeder bothered the birds. The pigeons avoided the previously “hostile” human, even though that person was no longer disturbing the birds and even when the seed pile in the other patch got low.
The research team believes “that pigeons discriminated facial or other body or movement characteristics and used them to recognize and avoid the hostile feeder.” The coats the feeders wore covered around 90 percent of their bodies leaving only head, hands and shoes visible to the pigeons. In one experiment, the feeders were two women and in another experiment, one man and one woman did the feeding. The people were of similar height, size, and skin color. They wore different colored-long coats, too, and even swapped the coats in the course of the experiment.
The birds might have detected general body shape or face traits, write the researchers. “We do not know yet precisely which characteristics are used,” they admitted.
The researchers say that being able to discriminate between human feeders is “ecologically relevant” for the birds, because it means faster recognition of the safe human feeder. It leads to a gain in energy and time when foraging for food. Pigeons rely on humans for their food in cities, from either “benevolent” feeders or from people leaving scraps behind. Either way, it is to the birds’ advantage if they can recognize “the best human feeder.” How they do so, is still a mystery.
Neither feeder moved during the experiments, except to shoot photos, but pigeons are known to be able to detect and discriminate subtle movements, the researchers state.
Pigeons have been previously shown they can categorize and process decisions, all of which helps them navigate the urban environment. In a 1964 study with homing pigeons Harvard University researchers found that the birds could be trained to react to the presence or absence of people in photographs. The result showed “greater powers of conceptualization than are ordinarily attributed to animals,” the researchers wrote.
A recent study by researchers at the University of New Hampshire and the University of Manitoba in Animal Cognition has a catchy title that starts out with “Let the pigeon drive the bus…” Perhaps we should not go quite that far yet, although the pigeons in the study were able to efficiently plan a route with multiple stops.
References and links:
Ahmed Belguermi et al., Pigeons discriminate between human feeders Animal Cognition (2011) 14:909–914, DOI 10.1007/s10071-011-0420-7.
Brett Gibson et al., Let the pigeon drive the bus: pigeons can plan future routes in a room Animal Cognition. Oct 1, 2011. DOI 10.1007/s10071-011-0463-9
R.J. Herrnstein and D.H. Loveland. Complex Visual Concept in the Pigeon Science 23 October 1964, p. 551.