Brendan Borrell // Spectrum
Brendan Borrell // Spectrum

The Social Lives of Monkeys Might Aid Autism Research

Brendan Borrell // Spectrum
Brendan Borrell // Spectrum

About 1 percent of people on the autism spectrum have a mutation on the gene called SHANK3. On one Caribbean island, researchers are discovering that a significant number of the monkey population does, too, opening up a whole new avenue for scientists to study the condition. 

Spectrum, a news site for autism research, sent a reporter out to Cayo Santiago, an island owned by the University of Puerto Rico that’s also known as "Monkey Island." Located just off the eastern coast of Puerto Rico, it’s a primate research center where 1500 feral rhesus macaques, descended from 409 monkeys released by primatologists in the 1930s, can be studied in a natural habitat. It’s also an unlikely new hotspot for autism research, which has rarely been conducted with primates before. As many as one in eight of the island’s macaques have a gene mutation on the autism-linked SHANK3. 

By carefully observing and cataloging the interactions and social networks of the island’s monkeys, researchers like University of Pennsylvania neuroscientist Michael Platt can study how genetics plays into behavioral characteristics. 

As Spectrum reporter Brendan Borrell explains:

In 2013, Lauren Brent, Platt’s former postdoc and field research guru who is now at the University of Exeter in the United Kingdom, reported that a monkey’s social tendencies can be passed down from parent to child. She used techniques developed in human behavioral genetics to collect data suggesting that monkeys with few grooming buddies tend to have specific variants of two genes that govern serotonin levels in the brain. One these genes, TPH2, has been implicated in depression and autism. The more recent discovery of a natural SHANK3 variant is particularly intriguing, because it shows that even the most complex and subtle social behaviors can have a clear genetic signature.

This kind of research in the natural world supports lab work in which transgenic monkeys—engineered with SHANK3 mutations, for instance—can be studied to learn more about the underlying causes of autism. 

Read the whole story on Spectrum

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iStock
Crafty Crows Can Build Tools From Memory
iStock
iStock

Scientists have discovered yet another reason to never get on a crow's bad side. According to new research reported by Gizmodo, members of at least one crow species can build tools from memory, rather than just copying the behavior of other crows—adding to the long list of impressive skills that set these corvids apart.

For the new study, published in the journal Scientific Reports, an international team of scientists looked at New Caledonian crows, a species known for its tool usage. New Caledonian crows use sticks to pick grubs out of logs, sometimes stashing these twigs away for later. Tools are so important to their lifestyle that their beaks even evolved to hold them. But how exactly the crows know to use tools—that is, whether the behavior is just an imitation or knowledge passed down through generations—has remained unclear until now.

The researchers set up the experiment by teaching eight crows to drop pieces of paper into a box in exchange for food. The birds eventually learned that they would only be rewarded if they dispensed either large sheets of paper measuring 40-millimeters-by-60 millimeters or smaller sheets that were 15-millimeters-by-25 millimeters. After the crows had adapted and started using sheets of either size, all the paper was taken away from them and replaced with one sheet that was too big for the box.

The crows knew exactly what to do: They ripped up the sheet until it matched one of the two sizes they had used to earn their food before and inserted it into the dispenser. They were able to do this with out looking at the sheets they had used previously, which suggests they had access to a visual memory of the tools. This supports the "mental template matching" theory—a belief among some crow experts that New Caledonian crows can form a mental image of a tool just by watching another crow use it and later recreate the tool on their own, thus passing along the template to other birds including their own offspring.

This is the first time mental template matching has been observed in birds, but anyone familiar with crow intelligence shouldn't be surprised: They've also been known to read traffic lights, recognize faces, nurse grudges, and hold funerals for their dead.

[h/t Gizmodo]

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Jana Mueller
Ravens Can Figure Out When Someone Is Spying on Them
Jana Mueller
Jana Mueller

Corvids, the family of birds that includes crows and ravens, are canny beasts. They've been known to exercise self-control, count, hold grudges, and more. Now, new research suggests they possess at least a rudimentary Theory of Mind—the ability to attribute mental states to others.

A study in Nature finds that ravens can tell when someone else can see them, guarding their food when a peephole to their cache is open. While previous research suggested that birds might have an awareness of other animals' mental states, the results have been inconclusive. The Nature study is evidence that corvids can do more than just track other birds' gaze; they may understand the concept of "seeing."

Vienna-based researchers set up two rooms separated by windows that could be closed with covers. These covers had peepholes in them that could also be opened or closed. First, the 10 ravens were each allowed to cache food, while other birds were in the next room and the windows were open or closed. Then, they were trained to look through the peepholes to find food in the other room, so that they knew that the holes could be used to see through the window covers. Afterwards, each of the ravens was again presented with food with one of the two peepholes open. The adjacent observation room didn't have any birds in it, but the researchers played the sounds of another raven recorded during one of the previous trials.

When the birds heard the sounds of another raven in the next room, and the peephole was open, the birds behaved as if they knew they were being watched—they hid their cache of food quickly and didn't add more food to it as often, as if they knew that it might be compromised. However, they behaved normally when the peephole was closed.

This suggests that ravens don't just track their competitors' gaze to know when they’re being watched, but can infer from past experience when they can be seen.

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