A study has found that, like people, parrots have different dialects – and they’re shifting as their environment changes.
The study is published in Proceedings of the Royal Society B: Biological Sciences.
Many animals, like chimpanzees and frogs, have been shown to have “accents” in their calls – different tones and styles depending on location.
This team of US researchers has been studying a population of a parrot, the yellow-naped amazon (Amazona auropalliata), in Costa Rica since 1994.
The birds roost in large flocks overnight and forage in smaller groups, learning calls from each other as they go.
In 1994, 2005, and 2016, the researchers recorded evening and morning calls from the birds at a number of Costa Rican sites, as they were leaving and entering their roosts.
The researchers identified 3 distinct parrot dialects in the population in 1994 – called North, South, and Nicaragua.
In 2005, the researchers surveyed the population again and found little change.
But their 2016 survey, 22 years after the original and 11 years after the check-in, revealed large differences.
During this time, there had been intensive clearing in the environment, and the yellow-naped amazon’s status had been updated to “critically endangered” by the International Union for Conservation of Nature and Natural Resources (IUCN).
The researchers found a change in the North-South dialect border, new call variants in the South dialect area, and more “bilingual” birds who could use the South dialect in the North dialect area.
“Many factors can lead to cultural change including degree of isolation, population size, habitat quality, habitat heterogeneity, ranging distance and population turnover,” write the researchers in their paper.
“We have evidence for some of these factors but can only indirectly associate them with our data.”
The researchers emphasise in their paper that the loss of vocal culture among animals is an important part of biodiversity loss.
“Both fragmentation and population loss can disrupt culturally transmitted behaviours,” they write in their paper.