Photo: Zoo Leipzig.
The endangered Arrau, a giant South American river turtle, has unusual conversational attributes.
I remember a fad (perhaps it wasn’t a fad, perhaps it’s still going strong) of expectant mothers exposing babies-in-the-womb to classical music, art museums, and breathtaking scenery. The idea was to inculcate certain interests before birth. Turns out, there’s a turtle mom that does something similar.
Dino Grandoni writes at the Washington Post about turtles that “talk” to their babies before they hatch.
“Camila Ferrara felt ‘stupid’ plunging a microphone near a nest of turtle eggs. The Brazilian biologist wasn’t sure if she would hear much. She was studying the giant South American river turtle, one of the world’s largest freshwater turtles.
“ ‘What am I doing?’ she recalled asking herself. ‘I’m recording the eggs?’
“Then Ferrara — who works for the Wildlife Conservation Society, a U.S.-based conservation group — heard it: a quick, barely audible pop within the shells.
“The hatchlings seemed to be saying to one another, she said, ‘ “Come on, come on, it’s time to wake up. Come on, come on.” And then all the hatchlings can leave the nest together.’
“Researchers for decades thought of aquatic turtles as hard of hearing and mostly mute. … But recent recordings of these turtles’ first ‘words’ — before they even hatch — challenge notions not just of the turtles’ capacity to communicate, but also of their instinct to care for young. Now the discovery has spurred an urgent count of this talkative turtle’s numbers, and may shape protections. …
“Known locally as the arrau or tartaruga da amazonia, the giant South American river turtle lives throughout the Amazon and its tributaries. During the dry season, thousands of females at once crawl onto beaches along the river to lay their eggs. For other kinds of turtles, the mothering usually ends at the beach. Many turtle hatchlings are left by their parents to fend for themselves.
“But that’s not the case with the arrau. After nesting, females often hover by the shore for up to two months waiting for their eggs to hatch.
“So Ferrara and her colleagues wondered: are mother turtle and child turtle communicating with one another? To test the idea, her team spent months taping the turtles — on land and underwater, in the wild and in a swimming pool. The team recorded a wide repertoire of whisper-quiet calls from arrau of all ages.
“Embryos appear to chirp together to coordinate hatching and digging up to the surface. With so many jaguars and other predators lurking, it is safer for baby turtles to move en masse toward the river.
“The mothers, meanwhile, approach and respond to the calls of their young. Once the hatchlings reach the water, the baby turtles migrate down the river with the adult females, Ferrara’s radio-tracking research shows.
“When her team published an early study on turtle vocalizations a decade ago, Ferrara said, academic journals resisted putting the phrase ‘parental care’ in the title of a study about turtles. …
“But Ferrara and her colleagues have gone on to record vocalizations from more turtle species, including the pig-nosed turtle in Australia, Blanding’s turtle in Minnesota and Kemp’s ridley sea turtle in Mexico, one of the world’s most endangered. …
“Other researchers may have missed turtle noises since they tend to be quiet, infrequent and low-pitched — just at the edge of human hearing. Leatherback sea turtles, for instance, appear to have ears tuned to the frequency of waves rolling ashore. Some species can take hours to reply to each other.
Some species can take hours to reply to each other.
“ ‘Had we had a bit more expansive imaginations, we might have caught this earlier,’ said Karen Bakker, a fellow at Harvard’s Radcliffe Institute for Advanced Study who wrote about turtle vocalization in her book, The Sounds of Life.
“ ‘We’re looking for sounds in the frequencies we can hear,’ she added. ‘We’re looking for sounds at a temporal rate that is as quick as we speak.’ …
“As a group, turtles are more ancient than dinosaurs, and are central to many cultures’ creation stories. Yet today they rank among the species at most risk of extinction. Nearly three in five species may vanish, according to a recent assessment, with climate change, habitat loss and hunting posing risks.
“The Amazon once teemed with so many turtles, it was difficult to navigate. While Indigenous people have long relied on turtles for meat, the arrival of Europeans accelerated their decline. …
“The species still faces serious threats. A boom in dam construction threatens to cull their numbers. And a continued appetite for turtle meat sustains a lucrative illegal trade, where middlemen can buy an arrau for $50 and sell it downriver for $450. …
“For [Ferrara], the real fight is not in the field, but in the cities, convincing regular Brazilians to refrain from eating turtle meat. For her, changing the minds of just a few folks would be a victory.
“ ‘What I want is to see two or three people stop.’ “
More at the Post, here.
Turtles that take a long time to answer another turtle are like Bob & Ray’s Slow Talkers of America.
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