The avian flu outbreak which has devastated seabird populations has spread to otters, it has been confirmed.
Researchers testing mammals in areas where large numbers of birds had died from the virus, including Shetland, recorded nine positive cases.
The Animal and Plant Health Agency has published figures confirming bird flu in non-avian species, including otters and foxes.
One of the dead otters was in Shetland, with the others found in Fife and Skye.
They are thought to have caught the disease from scavenging infected bird carcasses.
Pete Bevington at Hillswick Wildlife Sanctuary said he knew NatureScot had been testing otters in Shetland but had not been made aware of any positive results.
He said it was a concerning development.
“Bird flu has been an awful situation,” he said.
“All we can do is hope that it moves on and nature deals with it.”
Fortunately, Mr Bevington said Shetland’s otter population was doing “very well”.
“People are telling us they are seeing more otters in the wild that they used to,” he added. “And that has been the case for the last few years.”
While saddened to learn of the death of a Shetland otter, Mr Bevington said the numbers affected appeared to be very low, which was some consolation.
Health experts said there was little danger to humans and no evidence of the disease passing between mammals in the wild.
However, people are warned not to handle sick birds.
In December, NatureScot reported that the number of bonxies at Noss nature reserve had fallen by 78 per cent, after bird flu decimated the breeding population.