Traffic injuries also pose considerable problems for otters, as new roads are built through their previously tranquil homesteads. Pollution from pesticides, PCBs, mercury and oil can all be severely damaging to the otter's health, when found in traditionally clean streams. But by far the greatest threat in our area is the risk of an oil spill. The Minch waters between Skye and the Outer Hebrides is still a major oil tanker route and it is argued by many that a spillage is just waiting to happen. The Exxon Valdez killed thousands of sea otters and otters were also effected by the Braer disaster in Shetland.
Otters communicate using vocal expression such as whistles, birdlike twittering and spitting.
They can also communicate using spraint. Over 100 different scent components of otter dropping have been identified. About 17 of these are thought to contain information on sex, age and even individual recognition, which can be used by other otters. Otters tend to live alone, except during mating and for a short time after the cubs are born. The young will stay with the mother for approximately 13-15 months.