Move Over Sheep, Doves Are Returning Home To Tiny Island Of Socorro

In the coming year, scientists are hoping to reintroduce the Socorro dove to Socorro Island, a place where the bird has died out.

Socorro, the ancestral home of the dove, is part of an island group off the west coast of Mexico nicknamed the Mexican Galapagos.

In the 1920s, the California Academy of Sciences noticed island birds and animals were disappearing fast. So the academy sent an expedition to Socorro with instructions to bring back live doves.

Juan Martinez, a scientist with Mexico's Institute of Ecology, hiked the same terrain as the researchers a century ago. He said he plans to slowly reintroduce the doves to the wild.

"We're going to camp in that area, where you see the green and the red," Martinez said. "In that area is a heavier forest and is where they found the Socorro doves. That's why all this exercise is helping us find the locations. The best place to bring them back is a similar place where they found them."

The original expedition brought back 17 doves and sent them to zoos and aviaries across the United States and Europe. The plan was to breed them in captivity.

But although they survived at the zoos, they died off on the island.

"Here on Socorro you have introduced sheep, introduced cats and introduced mice," Martinez said.

Cats and mice preyed on the birds and their eggs. But the biggest problem, Martinez said as he pointed to the hillside, was the sheep.

"That's probably the highest point where they completely removed vegetation," Martinez said.

The sheep chewed and trampled their way through the forest, destroying the Socorro dove's home.

"And at the end, all of that material goes to the sea and it is tons and tons of soil that were lost by the impact of sheep," Martinez said.

Martinez, along with his team, have spent the last several several years aggressively removing sheep and replanting native trees.

There's also ongoing work to rid the island of cats and mice. But even with all that work, Martinez said re-introductions are full of uncertainty.

Michelle Reynolds, a biologist for the U.S. Geological Survey and a reintroduction specialist, said to expect surprises when returning the doves to Socorro.

She said she knows of Hawaiian ducks that were moved from one island to another, only to take off over the open ocean and never be seen again.

"There could be a new threat, one that didn't exist when the species used to live there," Reynolds said.

For example, she said, avian diseases, such as West Nile, are more prevalent now.

It's also unknown how captivity might have changed the birds. The doves might have lost traits needed to live in the wild.

"You might lose some aggression; you might lose vigilance," Reynolds said. "There's lots of characteristics that can change over many, many generations in captivity."

Martinez said this might seem like a lot of work for one small species on a tiny island. But other birds on this island are teetering on extinction, he said.

He and other scientists believe the effort to return the doves to Socorro will also help the other endangered species.

"It's not restoration by restoring or reintroducing one species," Martinez said. "At the end what you want is to restore the ecological interactions that interplay on the island. And once you do that, the island will go back to its original course."

This reintroduction is a process scientists a century ago might never have imagined.

Martinez might not even see the end of it. It could be decades before the doves can flourish on their own.

It's a long, difficult and costly effort. But Martinez said he believes it's ultimately worth giving the doves — and the island — another chance.

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