Is there a species of bird more boringly familiar than Columba livia? What other bird can so predictably be found in parks and parking lots, on streets and rooftops? What other bird do we ignore unless he's right in our way and probably stubbornly pecking at a day-old bagel? None. Even the ubiquitous house sparrow, full of nervous energy and high pitched twittering, gets our attention more easily than Columba livia, the common pigeon.
Does that familiarity mean we know all about pigeons? No. In fact, these birds have a long history of surprising us, especially with their formidable intelligence.
In the middle of the 20th century, B. F. Skinner famously used pigeons to demonstrate that reward and punishment were prime motives for behavior. Confining pigeons in empty cages (known as Skinner boxes -- cruel to modern sensibilities) and giving them food if they performed a designated task, Skinner managed to teach the birds to "read" (recognize a couple of words) and play ping-pong (bat a ball back and forth). Belief in behavioral theory was once so strong that during WW II, Skinner was set to work on a project to develop a pigeon-guided missile! Military research not infrequently tends toward science fiction, but in this case reason prevailed; Project Pigeon was abandoned.
With a more nuanced view of both animal and human motivation and more sophisticated experimental techniques, modern researchers have been more adept at discovering the pigeons' cognitive abilities. Here's what we've learned in the past few years.
In Paris, researchers concluded that, like several other species of bird, pigeons can recognize individual people and that the recognition is probably based on the birds' perception of individual facial characteristics. A change of clothes didn't fool the pigeons; they saw right through the sartorial ruse and were still able to accurately recognize the people.
Even more bracing, in Tokyo researchers discovered that pigeons know themselves; that is, they can recognize video images of themselves. At this self-cognitive ability, the birds proved to be somewhat better the average three-year-old child.
And most recently, researchers in Vienna found that pigeons can learn to recognize screen images of humans (heterospecifics is the technical term) they've met in real life. In this study, as opposed to previous ones on recognition, the pigeons came to the experiment without having had any emotionally charged interactions (friendship or hostility) with the people in question. First, the birds were trained to distinguish between pictures of familiar and unfamiliar objects, and then, they proved able to transfer the familiar/unfamiliar dichotomy to a new situation and use it to recognize pictures of the people they'd met.
All of which argues that pigeons are good observers who know us well. But then, they've been living near us for a long time and we're not always the best neighbors. It's in the pigeons' interests to keep an eye on us -- and perhaps in ours to know just how well they can do that.