We've known for a while that bees choose their flowers based on what they see other bees doing. This type of learning by observation is a fairly complex social behavior. So how did bees master it? Now, a group of scientists say it all comes down to how bees use logic.
Numerous species throughout the animal kingdom learn new things by watching the behavior of others. Chimpanzees, for example, can learn how to use a new tool to get food by watching other chimps, or even by watching humans. And in the 1920s, Great Tits in England learned to break the foil caps of milk bottles to get the cream at the top — this technique became common knowledge among the birds within a couple decades. But this learning ability apparently isn't reserved for just "smart" animals.
Research in 2005 showed that the bumblebee uses observational learning, too. In the study, scientists allowed bees to observe the foraging behaviors of other bees through a Perspex screen. When the spying bees were allowed to forage alone (with a new, random array of colored, artificial flowers), they copied the color preferences of the bees they watched.
In the insect world, "learning by watching other things has only been shown in bumblebees," says Elli Leadbeater, a zoologist at the Zoological Society of London. Given bees' tiny brains, figuring out where to find nectar just by observing others seems like pretty complex behavior. But Leadbeater wondered: Is it really that complex or is there a simple explanation to it all?
To find out, Leadbeater and her team performed experiments in a wooden fight arena, which contained a wall with six colorless platforms serving as "flowers." Some platforms were filled with delicious sucrose, others with bitter quinine. They collected almost 160 nascent bees that had no foraging experience, and divided them into three groups. Bees in the sucrose group were allowed to individually visit the platforms — fake bees "foraged" on the sucrose platforms, while the quinine platforms remained empty. After repeated trials, the bees learned to associate food with other bees.
In a second round of trials, the researchers only put fake bees on platforms with quinine, causing bees in the quinine group to associate the yucky substance with other bees. "The bees learned: 'if I want sugar, I should go to flowers without other bees on it,'" Leadbeater explains. A third batch of bees — the naïve group — also visited the different flowers, but without any model bees around, so they made no connections between bees and food.
A bee looks on as other (fake) bees forage on orange platforms. Credit: Erika Dawson
The researchers then switched things up by adding color to the flowers: They marked half of the platforms with one color, and the other half with another color. They put individual bees in an adjacent room separated by a screen, and allowed them to watch as the model bees foraged (the fake bees stuck to one color or the other) for 10 minutes. The idea here is to have the bees learn to now associate the demonstrators with a particular color.
Leadbeater and her colleagues removed the fake bees, replaced the platforms with clean landings in a different arrangement and let the bees into the arena. Bees in the sucrose group preferred flowers that were the color favored by the model bees they saw, while the quinine group avoided popular flower colors. Naïve bees, on the other hand, couldn't care less about the color of the flowers.
So what exactly is going on here? Leadbeater suggests the bees are using a form of deductive reasoning called the law of syllogism. It basically goes like this: If A equals B and B equals C, then A must equal C. In the sucrose group, food equals other bees. But other bees also equal a certain color, such as orange. Therefore, food must equal orange. The case is similar for the quinine group. However, because the naïve group never learned that other bees signify (or don't signify) where to find food, they were never able to make the second connection between flower color and food.
A real bee chooses an orange "flower" after seeing a fake bee choose that color. Credit: Erika Dawson
One way to look at the research is to think, "Wow, bees use logic to find food!" Or you could think of it the way that Leadbeater does. "In a way, we are talking about something that looks as though it's really sophisticated: The tiny bee brain is seemingly deducing, 'Oh, I can find sugar by copying,'" she says. "It looks clever but it's simply a Pavlonian ability that just about anything can do."
Being able to make associations between things is actually pretty widespread, Leadbeater notes. In fact, this kind of "second-order conditioning" is used in scientific studies all time and has been demonstrated in everything from rats to fruit flies. Now, it seems, this simple associative framework may be behind some instances of observational learning. "So observational learning, which is something that seems to be an advanced skill and is seen in birds and primates, may not be something that requires you to be clever after all," she says.
But what do you think? Would you consider these bees to be smart?
You can find the study in the journal Current Biology here.
Top image courtesy of P7r7 | Wikimedia Commons