Baby talk: the UTRGV study on parrots gets noticed
Karl Berg, a behavioral ecologist and parrot expert at the University of Texas Rio Grande Valley in Brownsville, has published a major study in the prestigious scientific journal Proceedings of the Royal Society B, and it is attracting the attention of a number of other scientific journals and media. international points of sale.
The Canadian Broadcasting Corporation, Forbes, Times of London, Psychology Today and Science magazine are among the publications that interviewed Berg about the study, which contains two important findings from his research on vocal babbling in parrot nestlings. in Venezuela.
Parrots are a tiny and adorable species of parrot.
Human babies normally start babbling – goo-goo-ga-ga and so on – around six months old. Berg found the same thing happened with baby parrots: increasingly complex babbling as the hatchlings matured. The new study is based on his many years of research (plus another 50 years of research on parrots in general), which could help shed light on how human language evolves from babbling, he said. he declares.
“The most important thing was just to find a developmental babbling phase that was taken quite seriously in humans but also in songbirds and pygmy marmosets, a small rainforest monkey, bottlenose dolphins, a species of rainforest bat,” Berg said.
“Just identifying another lineage that has this is important because it expands our evolutionary perspective on why we have this linguistic ability, … which some scientists consider the biggest scientific question, because no science would exist if we didn’t have our language skills.”
Parrots are considered the most complex vocal mimics in the non-human world, making it all the more important to understand why this particular group of birds approximates human language more closely than any other, he said. declared. As anyone who’s ever had a parrot as a pet knows, they are socially complex and extraordinarily intelligent animals, even though historically that intelligence has been underestimated, Berg said.
A huge scientific mystery is how babbling functions as a precursor to language in humans, while the level of complexity of an infant’s babbling appears to be a reliable predictor of later cognitive function, he said. Also, if babbling is significantly delayed — at 10 months instead of 6, for example — there’s a good chance the child will later develop autism, Berg said. These are important things to know since autism isn’t normally diagnosed until around age 2, he said.
“There’s a lot of interest in understanding what’s going on there,” Berg said. “People have moved on to animals to try to understand better.”
Songbirds have been an excellent model for studying the phenomenon because of their sophisticated ability to mimic sounds and because they can be studied in captivity, he said. But while songbirds, at least male songbirds, only start singing when they reach sexual maturity, to attract a mate, parrots start vocalizing (babbling) in the nest, and so are the females. than the males that do, Berg said.
This is where the second major finding of the study comes in, one he concedes is difficult to explain even to an academic audience. It involves the endocrine system and the hormones that determine what the body is doing at any given time: going through a growth spurt, reproducing sexually, reacting to injury, being hungry, etc.
Testosterone and estrogen are the best known sex hormones, although that’s not all, and there are also other hormones, the so-called stress hormones, which Berg says are an unfortunate name due to the negative connotation of the word “stress”. “What they really are are ‘staying alive’ hormones,” he said.
The endocrine system is a looping system connected to the brain and other parts of the body. It tells the body what to do partly based on sensory information outside the body – its environment. If you’re being chased by a lion, for example, stress hormones direct glucose into the bloodstream to keep muscles working as fast as possible, Berg said. When you’re hungry, stress hormones tell the body to go into foraging mode, he said.
“When you’re feeling hungry, that hormone kicks in and you either go to the fridge, or just grab another cup of coffee without caring, or you go fishing,” Berg said.
The hardest-to-explain part of the study deals with how stress hormones work in developing parrot nestlings, which Berg and his research team in Venezuela — including his wife and research associate Soraya Delgado — were able to observe. through artificial nesting. tubes equipped with video cameras.
“When we saw the babbling happening in the nest, stress hormones came to mind,” he said.
Unlike male songbirds, which sing at maturity because sex hormones tell them to, evidence seems to show that both male and female baby parrots babble due to the influence of stress hormones. Berg also found that giving baby birds a small dose of stress hormone every day for a week resulted in more sophisticated babbling, he said.
“We found that the stress hormone actually increased the babbling repertoire,” Berg said. “It’s a little early to say it’s beneficial, but it certainly doesn’t look bad. … I think this shows that according to our predictions, we were right, that this part of the endocrine system plays a potentially beneficial role in language development. It is suspected in humans, but there is no solid experimental evidence.
Injecting human babies with stress hormone to see how it affects babbling and language development is ethically un-starting, he said. As a result, any evidence that the stress hormone part of the endocrine system plays a role in human language learning remains strictly circumstantial, Berg said.
At the same time, the study succeeds in highlighting what “appears to be a major difference between parrots and songbirds”, he said. Berg has also observed the babbling of baby red-crowned parrots, whose small range includes the Rio Grande Valley. While this doesn’t prove babbling exists in other parrot species, it does seem likely that it does in fact occur, he said.
“For a lot of people in the animal world, that’s pretty big, if you understand something like that,” Berg said. “We have shown the world something about the difference between these two important groups of birds. We have known for a long time that they differ. Why? Looking at early developmental questions and so on brings us closer to understanding why why the two groups are different, and again we know that parrots have a lot of similarities to humans that they don’t really share with songbirds.