Otter sprainting - the deposition of scent-marked droppings - is a key behaviour for territorial communication, and monitoring spraint sites provides valuable information on otter welfare and population status.
Sprainting behaviour is not just ecologically informative - it reflects the social welfare of individual otters. A territorial male that cannot establish and maintain a spraint network may fail to secure adequate food resources or breeding opportunities. River quality determines both prey availability and pollutant exposure; otters in cleaner rivers in healthier condition are more likely to maintain territories and breed successfully. The ongoing monitoring of spraint sites across Britain's rivers provides a welfare-relevant indicator of otter population health at landscape scale.