Photo: US Birds and Wildlife Preservation. Puerto Rican parrots develop accents from the adults around them.

Puerto Rico’s endangered parrots are facing a new threat to their survival: a miscommunication problem.

In a phenomenon never seen before, Puerto Rican parrots bred in captivity, with a view to being released into the wild, were communicating with a different dialect to the wild populations.

The new language posed a problem, because it meant that the reintroduced birds would not socialize and eventually breed with the wild parrots, seriously hampering efforts to reintroduce the birds to their natural habitat.

In the 1970s there were only 13 Puerto Rican parrots left in the wild, down from a population of a million when European colonizers first arrived in 1493. But deforestation and deprived the parrots of homes, and in recent years cataclysmic hurricanes like had blown forest parrots of their perches and wiped them out.

In a heroic effort to pull the species back from extinction by breeding the 13 lucky survivors, conservationists began to breed the parrots in captivity. It was a success and today more than 600 exist.

Around 2013, Tanya Martínez, then a master’s student at the University of Puerto Rico, began to notice that the Puerto Rican parrots didn’t all sound alike. “If you would go into the El Yunque forest to work with the wild population, it would almost sound like a different species” from the captive birds, says Martínez, whose paper appeared recently in the journal Animal Behaviour.

The potential language barrier is a concern, says Timothy Wright, a biologist at New Mexico State University who wasn’t involved in the research. To be successfully reintroduced, he says, parrots must be able to rely on communication with their peers, particularly to strengthen relationships in their individual communities.

 The problem turned out to be that the baby parrots in the breeding program had picked up a Dominican parrot accent from the Hispaniola parrots that had been used as adoptive parents for baby Puerto Rican parrots.
Now when the adolescent Puerto Rican parrots were released into the wild, they could not communicate properly with the wild adult Puerto Rican parrots or enter into the parrot dating community where they would find mates and start new parrot families in the wild.

Fortunately, there was a solution.

Birds scheduled for release into the El Yunque forest now first spend a period at a halfway house where they can watch, listen to, and learn from their soon-to-be peers.

Conservationists have also stopped using Hispaniolan parrots as foster parents, now that there are enough Puerto Rican parrots to raise their own chicks.

And earlier this year, the team released 30 captive parrots into the El Yunque forest to replace the population that died during hurricane Maria. Their dialects, though not quite the same, will again fill the forest with a cacophony of parrot calls.