By Dr. Becker
In order to tell one item from another, it's necessary to observe the significant features of each. This is a skill once thought to be exclusively human, but research is proving we aren't alone in our ability to categorize. The most recent species to demonstrate talent in this area? Pigeons!
Pigeons, Like Humans, Are Able to Categorize Common Items
According to Ed Wasserman, University of Iowa professor and co-author of a recent paper published in the Journal of Experimental Psychology: Animal Learning and Cognition1:
"The basic concept at play is selective attention. That is, in a complex world, with its booming, buzzing confusion, we don't attend to all properties of our environment. We attend to those that are novel or relevant."
As it turns out, selective attention, which has always been viewed as a uniquely human skill, is vital to survival, says lead study author Leyre Castro. For example, animals in the wild must be able to tell the difference between food and a potentially toxic substance. They must also distinguish between friend (a harmless animal) and foe (a predator).
The UI study also suggests that pigeons appear to follow a thought process similar to humans when noting differences among objects. Learning about an item's important features goes hand-in-hand with the ability to use those features to categorize the item. The researchers assumed the pigeons in the study would learn in two phases. The first phase would involve learning what was relevant about the object, followed by the second phase, which would include learning the appropriate response. But what they found instead was that the pigeons' brains learned and categorized simultaneously.
Pigeons Use Selective Attention to Distinguish Between Sets
For the experiment, the researchers first trained the pigeons using food rewards, then put them in front of touchscreens containing two sets of four computer-generated images including stars, spirals, and bubbles. The pigeons then had to determine the differences between the two sets – for example, perhaps one set contained stars while the other contained spirals.
The researchers observed which images the pigeons pecked on the touchscreen to determine whether they were focused on the relevant, unique features of each set. Since a pigeon's beak is centered between its eyes, it's assumed that where the bird is pecking is where it is also looking.
So were the pigeons pecking at the stars in one set and the spirals in the other set? Yes they were! The birds learned to select – with about 85 percent accuracy – whether an image belonged in one category or the other. They demonstrated this ability by first pecking repeatedly on an image and then selecting (pecking) one of two boxes as the category.
The researchers concluded the birds were using selective attention to put the objects in appropriate categories.
'We need a dose of humility in our evaluation of other species.'
Wasserman, in an interview with Discovery News, said:
"Most people would credit pigeons with little intelligence, but we've been studying them for 40 years and they seem to engage in highly complex visual tasks that require a considerable amount of learning. We need a dose of humility in our evaluation of other species."
I couldn't agree more with this statement. As a wildlife rehabilitator, I've found pigeons to be smart and cooperative patients. Sadly, many people erroneously find them to be "dirty" and loathsome creatures.
According to the researchers, this finding can be expanded to include other animals like fish, reptiles, or other bird species – creatures without appendages. It cannot be applied to animals with appendages, however, because they can be looking somewhere other that where their hand or paw is contacting the touchscreen.