A few years ago, Christian Lutz began to wonder if he was giving Callas enough credit. Lutz, a biologist at the University of St Andrews in Scotland, and his team were capturing wild New Caledonian crows, challenging them with puzzles made of natural materials, and then releasing them again. In the test, birds faced a perforated log containing hidden food and were able to retrieve the food by bending the stem of the plant into the hook. , the researchers removed the bird from the dataset.
But Rutz said he soon began to realize that he hadn’t actually studied the skills of New Caledonian crows. Although he had only studied a subset of New Caledonian crows, they quickly approached strange logs they had never seen before.
The team has changed protocol. They began giving the more hesitant bird an extra day or two to acclimatize him to the environment, then challenged the puzzle again. “We found that a lot of these retested birds suddenly started getting involved,” says Lutz. “They just needed a little extra time.”
Scientists are increasingly realizing that animals, like humans, are individuals. They have distinct tendencies, habits, and life experiences that can affect their performance in experiments. That said, some researchers argue that many published studies of animal behavior may be biased. Studies that claim to show something about the species as a whole, such as how green turtles travel specific distances or how chaffinchs respond to rival calls, can be found in individual animals captured or housed in specific ways. may say more about or share certain genetic traits. This is a problem for researchers trying to understand how animals perceive their environment, acquire new knowledge and live.
“The samples we draw are very often very skewed,” says Rutz. “This is something that the community has been talking about for quite some time.”
In 2020, Rutz and his colleague Michael Webster, also at the University of St Andrews, proposed a way to address this problem. They called it Strange.
This video from one of Christian Lutz’s experiments shows wild New Caledonian crows bending plant stems into hooks to retrieve food from holes. Although some birds were initially hesitant to approach the material, Rutz found that many of them could solve the puzzle over time.
Personality is not just for people
Why “Strange”? In a 2010 article in Behavioral and Brain Sciences, the people studied in much of the published psychological literature were queer and eccentric drawn from Western, educated, industrialized, affluent, and democratic societies. Yes, suggesting that they are among the least representative populations. Generalize about humans. A researcher might draw sweeping conclusions about the human mind if he really studied only the minds of, say, the University of Minnesota undergraduates.
A decade later, WEIRD inspired Rutz and Webster to publish a paper in Nature titled “How STRANGE are your study animal?”
They suggested that fellow behavioral researchers consider several factors about study animals. They are called social background, captivity and self-selection, breeding history, acclimation and habituation, natural variation in reactivity, genetic makeup, and experience.
“The first time I started thinking about this kind of bias was when I was using mesh minnow traps to collect experimental fish,” says Webster. He speculated that more active sticklebacks were more likely to swim into these traps, which he confirmed in the lab.”Now we’re trying to use nets instead,” he said, Webster said. I catch a wider variety of fish.
That’s trappability. Other factors that make an animal easier to capture than others, besides its activity level, include bold temperament, inexperience, or simply hunger for food.
In other studies, pheasants housed in groups of 5 performed better on a learning task (identifying which hole contains food) than pheasants housed in groups of only 3. is shown. This is the social background. Captive-reared jumping spiders were less interested in prey than wild spiders (housing history), and bees learned best in the morning (natural changes in reactivity). and so on.
