In Hertfordshire we have seen water vole populations drop by more than 90% over the past 50 years. This is due to habitat loss and the species falling prey to non-native American mink, which were released from fur farms in the late 1960s.

Nowadays, there is remedial action taking place across the region, and indeed the country, to get water voles back on our rivers. The Trust’s aim is to get water voles back on all Hertfordshire rivers by 2030 and with mindful habitat management, mink controls and water vole reintroductions taking place, we are hopeful that the water vole will, once again, become a familiar sighting in years to come.

Water voles were popularised by Kenneth Grahame’s Wind in the Willows, where the water vole character was called ‘Ratty’. A misleading name - water voles are not rats, so let’s explore below exactly what they are, how they live and what they contribute to their river habitats:

Water voles can be up to 22cm long, excluding their tail. Other identifying features include a chestnut-brown fur coat, a chubby, round nose, small dark ears buried in their fur, a furry, thin tail which is usually half the length of the body. They can weigh between 150g – 300g, about the same as two apples.

Water voles breed rapidly. Water voles typically produce three or four litters a year, with up to five young or ‘pups’ each time. With the average lifespan being six months to 18 months, it’s not impossible that a female water vole could deliver 30 or more pups in her lifetime!

Water voles are mini ecosystem engineers. They keep the banks in good condition by munching back vigorous plants allowing the less vigorous to thrive. This increases biodiversity in the areas they populate.

Water voles are important in the food chain. It’s not just the American mink who predate on water voles, many other predators do too – in fact, conservationists refer to them as ‘nature’s chocolate biscuit’ such is their place in the food chain. It’s a key reason why only approximately 20% of the water vole population survive through winter.

Water voles need a habitat that supports their survival. This must offer sufficient food sources, predominantly lush vegetation, but also a supplement diet of fruits, bulbs, twigs, buds, roots, as well as tadpoles and frogs. Shelter is another important factor as is an environment reasonably safe from predators. With water voles preferring calm waters, slow-moving rivers, such as our coveted chalk rivers can be ideal habitats for them to thrive.

Water voles live in burrows. They make their homes in the banks of rivers, ditches, ponds and streams by digging with their teeth and feet. Their burrows are often excavated on the steepest part of the bank and frequently have underwater entrances to help them escape or flee from danger.

Water voles leave their mark. Mapping out their territories between February and November, water vole latrines will show you the areas that they populate. Look for dark green, cylindrical droppings – similar in size and shape to a tic tac! Females transfer their scent from glands in their rear onto their feet which they then transfer onto the droppings to mark their territory when they have young to feed. When the latrines appear to be trampled upon, it’s a sign that breeding is taking place place. Water voles are messy eaters and will leave uneaten sections of stems in piles along the bank – look out for reeds and grasses with 45-degree angled cuts to one end where the water vole will have bitten the stem. Water vole tracks can be  identified with care and experience – they have four toes on their forefeet and five on their hindfeet. Another sign of water presence or past presence is a series of doughnut-shaped holes on the water’s edge or up to 3m away from it.

Water voles need help in protecting their habitats. We can all play our part in helping to protect water voles by conserving water every day. In doing so, we are helping to maintain the health of our rivers. This is particularly pertinent at this time of year when water resources are stressed and our rivers and wetlands are impacted by increased water usage in a changing climate. Find out more by watching the Save Water Save Wildlife video here.

Water voles need new places to live. If you are a landowner and would be interested in discussing the potential of a water vole reintroduction on a watercourse running through your land, please get in touch with Herts and Middlesex Wildlife Trust by emailing info@hmwt.org

Interested to know more? Read about our latest water vole reintroduction on the River Beane here.

Header image cc Terry Whittaker