He is not a Dr Doolittle from the real world. She is an ecologist in Christchurch, New Zealand, specializing in a little-known scientific field: bird dialects.
While some birds are born by knowing how to sing innately, many must learn to sing by adults - just like humans. These birds can develop regional dialects, which means that their songs sound slightly different depending on where they live. Think of the accents of Boston and Georgia, but for the birds.
Just as speaking the local language can facilitate the integration of humans, speaking the local dialect of birds can increase a bird's chances of finding a companion. And, more worryingly, just as human dialects can sometimes disappear as the world becomes more global, bird dialects can be shaped or lost as cities develop.
The similarities between human language and the song of birds are not lost on Molles - or on his colleagues who are experts in bird dialect.
"There are wonderful parallels," said American ornithologist Donald Kroodsma, author of "Birdsong for the Curious Naturalist: Your Guide to Listening". "Culture, oral traditions - it's the same thing."
The first bird dialect experts
For centuries, birdsong has inspired poets and musicians, but it wasn't until the 1950s that scientists really began to pay attention to bird dialects.
One of the pioneers in the field was a British behaviorist by the name of Peter Marler, who became interested in the subject when he noticed that the chaffinch in the UK sounded differently from valley to valley. other.
At first, he transcribed bird songs by hand, according to a profile of him in a publication by Rockefeller University. Later, he used a sonogram, which Kroodsma describes on his website as "a musical score for birdsong". ("You really need to see these songs to believe them, our eyes are so much better than our ears," said Kroodsma.)
In the 1960s and 1970s, scientists placed baby birds in soundproofing chambers to see if they would be able to sing their songs, according to ornithologist David Luther.
Scientists have discovered that some birds - those who learn their songs - couldn't sing at all. "They just continued like babbling for their whole lives," he said. These birds are known as "real songbirds". In other birds, song was innate. "When they came of age, they could just sing a perfect song without a problem."
When birds copy adults, scientists have discovered that they sometimes make a mistake. This error is in turn copied by other birds, and a local dialect develops. This means that dialects can only exist in real songbirds because they have a "learned oral tradition," says Kroodsma.
Dialects can also be created as the birds adapt to the local environment, said American ornithologist Elizabeth Derryberry. Birds that can be heard better can find a partner better, which means that their song is more likely to be passed on from generation to generation.
It is an idea developed by Bernie Krause, the founder of the soundscape ecology, that animals make sounds in different places so they can all be heard.
Some dialects change quickly - even during a breeding season. Other birds keep their dialects for decades. When Luther studied the San Francisco dialects of white-crowned sparrows - a common bird in North America - he found that some dialects had not changed at all in 40 years.
Dialects and dating (in birds)
For something that is often the result of a copy problem, dialects can be very helpful.
According to Molles, birds communicate for two reasons: either they try to denounce their neighbor, or they try to attract females. "Nothing very poetic, unfortunately," she quips.
When it comes to defending a territory against other birds of the same species which are not local in the region, knowledge of the local dialect allows for a more complex interaction. Imitating a song note for note is considered aggressive for birds, so having a larger repertoire means that a bird can get its message across without intensifying combat interaction.
Knowledge of the local dialect is also helpful in finding a romantic partner.
In many species, the male sings. According to Molles, females tend to prefer a familiar dialect - this suggests that male birds know the area, have territory, and are not just "someone passing by". Some birds are bilingual, even trilingual - perhaps because they grew up around different local dialects. When they mate, they choose to sing the local dialect of where they choose to settle, said Luther.
But not having the right dialect is not an insurmountable barrier.
Kroodsma gave the example of a Prairie Warbler in Massachusetts, where he is based, who has returned every year for a few years. Although the bird has a very unusual song, it attracts females and raises babies every year.
"Someone might say," Well, there is the novelty effect, a man with a very different song and all women think it's sexy, "he said. "But it's just a crazy guess."
This is something researchers are thinking of in places like New Zealand, where threatened birds are sometimes reintroduced into new areas. Researchers want to be sure that if they reintroduce birds, they will reintegrate, even if they don't have the correct dialect.
According to Molles' experience, this tends to work if one group of birds is reintroduced at a time, so they have other birds with a strange dialect.
She was involved in the reintroduction of Kokako - a native blue-gray bird with a fiddle call - to an area of New Zealand hundreds of miles from their birthplace. At first, the new arrivals could breed among themselves, she said. But in the future, they could integrate. The offspring of newcomers will likely begin to interbreed with the offspring of the original population who have grown familiar with the new and the local dialect.
"The woman is not necessarily looking for someone who matches the song her father sang," said Molles. "She finds a companion that matches the area she is seeking to settle in - it's not just a bizarre bird that might not belong to it."
How Humans Change Bird Dialects
As cities around the world were locked out, a series of questions arose for Derryberry.
Over the years, birds had started to sing at a higher level in cities to be heard by the low buzz of traffic and construction. What would happen to the birds when the cities were silent? If it was quieter, would the new generation of birds sing at a lower pitch? And next year, at the time of reproduction, would they be heard once the noise of the city returned?
She is still working to answer these questions, but Kroodsma is skeptical that the brief period of calm could have been long enough to have an impact on bird dialects.
Even though our coronavirus shutdowns haven't changed bird dialects this time, it's worth thinking about how we shape - and destroy - bird dialects in general. Something as small as a power line might be enough to divide a population of birds and lead to the creation of new dialects, says Kroodsma.
In New Zealand, a land of birds where the only native land mammals are bats, there would have been a greater range of dialects before the arrival of humans and a reduction in bird habitat, says Molles .
Molles remembers finding historical records of an indigenous Kokako population that have now disappeared.
"Some of the songs on these tapes were just amazing - weird metallic sounds that you never would have guessed came from a bird," she said.
"It was quite depressing to hear some of these and think, we're never going to hear that again."
Design and graphics by Jason Kwok and Natalie Leung. Development by Marco Chacón.
