The Desertas Island is a place where time seems to stand still. It rises dramatically from the Atlantic Ocean like a jagged fortress in the Portuguese Madeira archipelago. However, the Desertas is an important haven for rare or endangered creatures and for them, time isn’t standing still.

Most famously, the island is home to the critically endangered Mediterranean monk seal, one of the rarest seal species in the world. It’s also home to rare pea-sized snails that are almost extinct. The snails were once abundant on the island but their number decreased sharply in the last 100 years. By the 2010s, spotting any tiny snails on the island became almost impossible. 

Now, researchers want to change that and restore the small snails to their former glory. Very slowly, of course.

A group of conservationists from Portugal’s Institute for Nature Conservation and Forests (IFCN) concerned visited the island multiple times between 2012 and 2017. They found 200 snails in those five years, which they sent to the zoos in the UK and France for breeding purposes.

“The snails were believed to be the very last of their kind on the planet. Sixty of them were flown to Chester Zoo, where our invertebrate experts worked to establish a unique breeding program in a last-ditch attempt to boost numbers and save the species,” the Chester Zoo team said.    

The breeding program turned out to be a great success. The conservationists successfully bred 1,329 snails and recently released them to Bugio, one of the Desertas Islands which is free from rodents, goats, and other invasive species that pose a threat to the tiny snails.

Human care saved the snails

Saving the Desertas Islands snails was quite challenging, as they had never been bred under human supervision before. The conservationists knew nothing about the conditions best suited to help them thrive. 

“It was a huge responsibility to begin caring for them. They’d never been in human care before, and we had to start from a blank piece of paper and try to figure out what makes them tick,” Gerardo Garcia, Chester Zoo’s head of ectotherms told The Guardian.

They started by placing the snails in a shipping container that had been converted into a safe breeding room with temperature, humidity, and other conditions similar to their natural home. To understand the requirements for the animals’ growth, the zoo team spent hours caring for each snail and observing its behavior and reaction to different conditions. 

Once their survival was ensured, they focused on developing a successful breeding strategy for the animal. It took them a few months, but eventually, the zoo team successfully figured out how to breed the Desertas Island snails, producing multiple generations. 

“Within a few months, we were able to crack the breeding of the Desertas land snails, successfully breeding multiple generations. This was key because it meant we could then support other zoos and establish a network, breeding them in the substantial numbers needed to have a chance of saving the species.”

Introducing the snails back into the wild

From the 60 snails, the Chester Zoo team received in 2017, they raised 1,329 snails. Recently, these tiny cute shell-toting creatures were released to Bugio island in the same archipelago. 

However, they’re still being monitored. Each snail is marked with infra-red paint, which will allow the zoo team to understand how well these animals adjust to their new home. 

The success of this experiment will not only bring back Desertas Islands snails but also raise hopes for many other endemic animals facing the danger of extinction. 

“These snails are incredibly precious. The Desertas islands are the only place in the world where they can be found and so we’re striving to do everything we can to give them the best possible chance for the future. For 100 years we thought they’d gone forever, but now there’s new hope,” Dinarte Teixeira, a conservation biologist, said.