The Riverbank as a Living Map

A quiet riverbank at first light is one of Britain’s most underrated wildlife experiences. Otters are back on many of our waterways, but they remain shy, mostly nocturnal and extraordinarily good at not being seen. The secret is to stop looking for the animal itself and start reading the signs it leaves behind. Every bend, mudflat and grassy tussock can tell you where an otter has travelled, fed and rested. Tracking is not about chasing a glimpse; it is about piecing together a story written in scent, mud and flattened grass. With a little practice, you can follow that story for miles without ever disturbing its author.

Spraints: The Otter’s Calling Card

The most reliable sign is the spraint – an otter’s droppings, left deliberately in prominent places as a territorial marker. Once you know what to look for, you will find them on flat stones, tussocks, log ends and gravel bars, often at the junction of two watercourses or beside a pool. Fresh spraints are dark, tarry and glisten slightly; older ones fade to grey and crumble. They typically measure 2–7 cm and are packed with fish scales, small bones and the occasional crayfish shell. The smell is distinctive: often described as fishy, but also strangely sweet, like jasmine tea or new-mown hay. Do not dismiss a spraint because it looks like a small, dark sausage – that is exactly what it is.

• Look on raised, obvious features: stones, mossy hummocks, fallen branches.
• Check under bridges and beside tributary mouths – classic marking points.
• Fresh spraints are dark and glossy; old ones are pale and dry.
• Use a stick to tease one apart – the fish bones confirm the identity.

Footprints, Slides and Runs

Otter footprints are unmistakable once you have seen a clear set. They show five toes, a broad webbed shape and a large central pad. A hind foot is typically 7–9 cm long, with the webbing often visible in soft mud. Look along the water’s edge, especially after rain, when the mud is smooth and receptive. Even better are slides – smooth, muddy chutes on steep banks where otters enter and leave the water. They use these repeatedly, and you will often find tracks, spraints and flattened grass nearby. A run is a narrow, well-worn path through vegetation, often connecting two pools or a river to a nearby ditch. Follow it quietly and you may find a couch – a flattened resting place in tall grass or reeds – or a holt, a den under tree roots or in a rocky bank.

• Check muddy margins, sandbars and the edges of livestock drinks.
• Slides are often 30–60 cm wide and polished smooth by repeated use.
• Runs are low tunnels through grass, nettles or reeds – look for fresh green growth.
• Feeding remains – chewed fish, frog legs or bird feathers – often sit nearby.

Timing Your Visit: Dawn, Dusk and Weather

Otters can be active at any hour, but your best chances come at first light and last light. In summer, dawn is often quieter and the light is kinder for watching; in winter, dusk arrives early and otters may be abroad before dark. Avoid bright, breezy afternoons when disturbance is high. Overcast, mild, still days after rain are excellent – the water is rising, fish are moving, and scent lingers. Heavy rain can wash away tracks, so visit as the rain eases. Cold, clear nights often mean otters are hungry and active at dawn. Pick a stretch of river with plenty of cover, pools and riffles, and arrive at least half an hour before sunrise. Patience is your most important piece of kit.

Fieldcraft: Watching Without Disturbing

Minimal disturbance is not just polite – it is the difference between a fleeting glimpse and a proper sighting. Otters have excellent hearing and a keen sense of smell. Approach the bank slowly, keeping low and using trees, reeds or bankside vegetation as cover. Always keep the wind in your face; if it shifts, move on. Use binoculars rather than creeping closer. Never corner an otter or block its route to water. Keep dogs on a short lead and well away from the bank. If you do see an otter, freeze, watch through optics and let it go about its business. A quiet, still observer is often ignored; a rustling, fidgeting one is gone in a ripple.

• Wear dull, quiet clothing – no rustling waterproofs if you can help it.
• Use a red filter on a torch if you must walk in the dark.
• Stay at least 20–30 metres from any otter you spot.
• Never follow a slide or run into dense cover where a holt may be.
• Take only photographs – leave tracks, spraints and vegetation untouched.

Other Signs and Sharpening Your Senses

Beyond spraints and tracks, look for anal jelly – a clear, gelatinous substance left with spraints – and scratch marks on tree roots or clay banks. Listen for the otter’s high-pitched whistle, a sharp “hweet” that often betrays a family group. Smell the air near a suspected marking point; that jasmine-tea scent is a giveaway. As your skills grow, you will start to see the riverbank as a web of otter highways. Practise on a local stretch after rain, keep a notebook of what you find, and return at different times of day. The more you look, the more the quiet riverbank reveals – and the better your chances of sharing a dawn with one of Britain’s most charismatic predators.