Having almost completely disappeared from British waterways in the 1970s, efforts to save Otters from extinction have proved to be working. Otter population numbers in the UK fell drastically with increasing levels of water pollution but they have recently been reported as being found in every county in the country. These beautiful mammals can often be difficult to spot though but their prints in the mud are a tell-tale sign of their whereabouts.
By looking more not just for the animals themselves but for the distinctive clues that they leave behind, a whole new element of the natural world opens up. Different animals have different prints which can vary widely between species. Below is a small collection of the tracks of a number of different animals which are found around the world in mud, snow and even sand.