December 2, 2011
Paper Wasps Learn Faces
Researchers at the University of Michigan recently studied paper wasps and their ability to recognize wasp faces. They discovered that the species Polistes fuscatus has a special ability to learn faces and retain what they learn.
According to Michael Sheehan, who worked on the research with evolutionary biologist Elizabeth Tibbetts, “Wasps and humans have independently evolved similar and very specialized face-learning mechanisms, despite the fact that everything about the way we see and the way our brains are structured is different. That´s surprising and sort of bizarre.”
In the study the researchers set up a T-maze and placed different images on each end of the T. When the wasps picked the correct image they were given a reward. The researchers discovered that the wasps were able to differentiate between unaltered images of their own species faster than images of their favorite prey, caterpillars, two different geometric patterns, or a pair of computer-altered wasp photos.
The scientists then tried the wasps on altered images, such as removing an antenna or moving an eye. When exposed to these changes the test subjects performed much worse on the facial recognition test.
Sheehan said, “This shows that the way they learn faces is different than the way they seem to be learning other patterns. They treat faces as a different kind of thing.”
The scientists speculate that it is important for this particular species of wasp to learn faces between of the social structure of the nest. For these wasps there are typically multiple queens where the work is shared including cooperative raising of the offspring. But there is competition in the social hierarchy among the queens. Remembering who has become dominant keeps individuals from repeating the same battles and wasting important energy and helps to sustain relative stability in the colony.
The results of the research are available in the December 1 version of the online journal Science.
Image 1: Like humans, Polistes fuscatus paper wasps recognize individuals by their unique facial patterns. This photo shows a paper wasp queen on an early nest. Credit: Michael Sheehan
Image 2: Polistes fuscatus paper wasps have extremely variable facial patterns that they use to recognize each other as individuals. This montage displays some of the variation seen in female paper wasp faces in this species. Credit: Michael Sheehan
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