CROCODILE HUNTERS: An Irish scientist has discovered a previously unknown species of crocodile.

When Kilkenny woman Tara Shine heard about the shy cave-dwelling crocodiles of eastern Mauritania, she put it down to folklore or mistaken identity.

The semi-nomadic Arab settlers in the villages of the Hodh region of Mauritania often told her around the camp fire about the diminutive and elusive mountainy crocodiles .

"I didn't believe them at first, it seemed impossible," says Shine, who was a volunteer development worker there and is fluent in the local dialect, Hassaniya.

"There had been no previous record of crocodiles in that part of Africa. The nearest reported were in the Tagant region further west and it seemed far-fetched they would survive in such arid conditions. Nile crocodiles normally inhabit freshwater swamps, rivers and lakes. They rarely venture far from water. I asked them if they might actually be big lizards but they insisted they weren't."

Shine had been recruited by APSO to work on a German aid project surveying wetlands. The terrain is sandy and studded with rocky outcrops and entirely dependent on rain for water. The dry season can last for six to eight months, which made the sightings seem all the more unlikely.

When the stories persisted, she decided to investigate.

"When I called around to the caves, these small crocodiles were just hanging out, and showed no signs of aggression. They are only about two to three metres long, much smaller than is typical for a Nile species, which average at five to six metres."

The super-resilient species have adapted to a gradual change in climate over the past 5,000 to 8,000 years, which saw the region turn from lush savannah to arid desert. When water evaporates in the dry season, they go into summer hibernation, keeping movements to a minimum. Their only exertion is the crawl outside their burrows or caves at night to lounge on the rocks.They have been spotted hiking from the lowland wetland up mountains in search of permanent pools of water after a prolonged period of drought.

Happening upon such an important ecological find can be frustrating when you have no one to share it with, says Shine.

"I was literally in the mountains in the middle of nowhere. I had no access to the telephone or the Internet and no way of telling the outside world what I'd found. The first people I told were a group of German herpetologists attached to the Koenig museum in Bonn who took the news back to Germany."

She has since worked with zoologist Hemmo Nickel from the University of Mainz in Germany, under the supervision of Prof Wolfgang Böhme of the Koenig museum, radio-tagging the crocodiles to monitor their movements. There are believed to be around 20 communities of this species, with a population of 10 to 40 animals in each.

The locals believe the crocodiles are sacred. "They have given them a mythical value and are convinced if they go, the water will go too. In an area where water is in such short supply, it's easy to understand why they place such importance on them."

Shine, who recently turned 30, is working on her PhD on ephemeral wetlands in eastern Mauritania at the University of Ulster in Coleraine, where she did her primary degree.

"I am planning to do a film and to do further research with the guys in Bonn. We know so little about them, what they eat and how much they move around from the wet to the dry season. There is so much to learn."