Otters are making a comeback in the River Clyde, which is being cleaned up in the wake of heavy industry such as its world-famous shipyards.
An abundant food source is attracting otters back to the river
The otters are being encouraged by the increasing numbers of fish in the river, which is now less polluted.
The exact number is unknown, although an otter count is planned for later this year.
But experts have warned that facelift schemes along the Clyde could lead to the animals being driven out again.
Conservationist Dorothy Simpson, from Scottish Natural Heritage in Inverclyde, said: "There's always the risk that if redevelopment is not sensitive enough it will not meet the otters' needs."
But she added: "Because the redevelopment isn't as destructive as the old shipyards were, there's plenty of scope to accommodate both the otters and the redevelopment.
"A lot of these redevelopments include things like houses and open space. People are looking to see that.
"If the developers are developing for that and for people to have a better environment, that will suit the otters too."
A rebuilt section of the A8 will include an underpass for otters.
'Top of pile'
Ms Simpson added: "If the habitat's right for otters, it's right for a lot of different things. They're top of the pile in terms of prey species.
"They'll be hunting for fish and crustaceans. They're indicative of good, rich habitats.
"We're taking better care of our water courses. We're allowing plants to grow along the sides of them, which are really important to enable otters to travel up and down the water courses.
Stretches of the River Clyde are being cleared and redeveloped
She continued: "Bare rocky edges or bare brick walls along water courses mean otters have nowhere to shelter.
"But now we're inviting them back in by allowing plants and trees to grow along these areas."
Conservationist Petrina Brown stressed that it was also important to keep the burns that fed into the Clyde free of pollution.
"Rivers and streams are very important because they act as wildlife corridors," she explained.
"These are important because animals use them to travel back and forth and this allows migration."