A rare snail species which is part of a West Coast relocation programme is showing signs it could survive on its own.
More than 6000 Powelliphanta augusta snails were removed from their original habitat near the Stockton mine in Buller in 2007 so that Solid Energy could extend its operations.
The snails that were relocated just north of the mine, where conditions are similar to their original home, have built a new habitat and their population is booming.
But those moved to other areas are barely surviving.
Solid Energy says 1600 snails still in captivity are doing the best and high breeding numbers mean some will have to be released in the next six months.
The company says it's too early to decide whether all the snails could be moved to the new habitat in which they are thriving.