The calling cards of Sussex mammals

22 February 2021 | Posted in Guest blogger
The calling cards of Sussex mammals
Harvest Mouse nests © Laurie Jackson

By Laurie Jackson

Laurie Jackson is an Ecologist and Wildlife Lecturer, who regularly delivers talks for the Trust about the wonderful and varied small mammals of Sussex. Here she tells us about how you might to able to spot their tracks and trails.

In the depths of winter the screams of a vixen slice through the night. She's looking for a mate, and she doesn't care who knows about it. Fast forward to May, and the congested snuffle of a male Hedgehog reveals his efforts to convince a female to mate, as he circles her hopefully. Anxious Roe Deer calls can startle at any time. Their barks tinged with surprise, as if they've been caught in the middle of something underhand.

Rosie the fox by Tom Lee

© Tom Lee

Although mammals do offer us some acoustic signs of their presence, they often lurk in the shadows, preferring not to advertise their presence. Except they do. And once you know what to look for you can find their calling cards everywhere.

We wouldn't be talking mammals if we didn't start with dung/droppings/scat/poo. Whatever you want to call it, you can't avoid it if you want to track a mammal down. If you've heard grunts in the garden, a rummage in the vegetation may reveal Hedgehog poo. Although it could be discounted for a dead slug at first, this is much more special. The Hedgehog's insectivorous life means its poo is filled with insect remains, and fragments of beetle wing cases can give them an extravagant sparkle.

Hedgehog poo

Hedgehog poo

Many mammals have dual-purpose dung, designed to leave a clear message long after they have moved on. The tapered and twisted scat of the Fox is often left in a prominent location. Those who dare to take a closer look will see it's crammed full of fur, bones and even seeds. They will probably also get a whiff of its musky odour.

Some species habitually use latrines, which communicate clear messages about their territory. Badger dung varies depending on the seasonal larder, fluctuating from firm, purple, blackberry-laden dung to something a lot less appealing when they have feasted on worms. Their latrine sites can be huge, and those at the boundary between clans have the air of a battlefield.

If you are close to slow-flowing water with lush vegetation, there's a chance of spotting a Water Vole, or a Water Vole latrine at least. Their droppings are about 1cm long, green-brown and rounded at both ends. Although usually left in distinct piles, these can be flattened down by scent-marking males. Water Voles are not discreet when it comes to leaving clues about their presence. As well as their latrines you can find piles of abandoned plant stems, with obviously gnawed ends, and the entrances to their burrows, which are usually around 4-8cm across, along the riverbank.

The entrances to burrows created by the smaller Bank and Field Voles are only around 3cm across and found more widely. Field Voles are particularly fond of rough grassland, and if you carefully peel long grasses back you can find their meandering pathways and may even spot one of their shredded grass nests. Field Voles also leave piles of vegetation and create latrines with smaller droppings than a Water Vole.

The Harvest Mouse can also be found clambering around long grassland and wetlands. This tiny rodent is tricky to spot but it is an accomplished architect and weaves round nests from meticulously stripped vegetation. The mice use broad-leaved grasses, which they don't cut from the plant, leaving the nest suspended in vegetation (usually between 0.5-1m).

Another creative is the Hazel Dormouse. It also weaves a nest but prefers to use strips of bark and may include leaves. Hazel Dormice are tied to woody habitats and rely on a variety of fruits, flowers and nuts across the year. During autumn, a search for cast off hazelnuts can reveal their presence, as they leave a smooth circular hole in one side of the nut. Mice and voles also leave a circular hole but running a fingernail around its border will reveal ridged tooth marks.

Grey Squirrel feeding signs scream impatience: hazelnuts are split in two and pinecones ransacked. Outcrops like tree stumps can be a good place to look for these, but remains are often scattered around woodlands and parklands. Up in a winter canopy you can often spot squirrel dreys; a tangle of sticks and leaves, nestled in the branches.

Long established mammal abodes can leave markers around them. Nettle and Ragwort can develop around Rabbit warrens, promoted by the ground disturbance, whilst Badger latrines can nurture clumps of Bramble and Elder. And whilst Mole encounters are rare, heaps of freshly-churned soil signpost their whereabouts as they pursue worms through hundreds of metres of tunnel below your feet.

Many mammals are creatures of habit and commute along well-worn trails that can be followed through vegetation. Where these paths pass under fences you can find hairs snagged in the wire, and Badger hairs are particularly recognisable: long, pale and wavy with a black band.

Badger prints (1)

Badger paw prints

Following these pathways can reveal footprints in soft mud, with deer slots often spotted where they cross banks and ditches. British mammals have distinctive footprints that you can soon learn to recognise. Although similar to a dog, Foxes leave narrower, diamond-shaped marks. If you count five toes in a print it belongs to one of our mustelid species (Stoat, Weasel, Polecat, Otter, Badger, Pine Marten or American Mink). Badger footprints are one of the commonest finds and can be identified from their broad rear pad and five toes, often with further marks from their claws.

Web badger claw marks

Badger claw marks

If your path leads you to a mammal residence, you can use the size and shape of the holes to identify the species. Badgers and Foxes can both create extensive nest sites with lots of holes and spoil heaps. The holes are usually at least 20cm across and the entrances to Badger setts often look slightly squashed. Rabbit burrows have smaller entrances, around 10-15cm, and are usually in more open habitat, where large piles of round droppings along with signs of digging are easily seen. It is important to minimise disturbance if you find a burrow and remember that not everyone likes to receive visitors unannounced.

Nibbled nuts

Nibbled nuts

So whilst mammals can appear crafty and evasive, when you start to look there are signs all around. A few things to try:

  • Search for nibbled hazelnuts in the autumn and winter
  • Look for footprints in soft mud or snow
  • Hunt for Harvest Mouse nests in tussocky grassland with scattered scrub or wetlands
  • Explore Field Vole highways by getting down to ground level in long grass
  • Spy on garden visitors with a trail camera

To learn more about mammals and how to track them down:  

Sussex Mammal Group

The Mammal Society

People's Trust for Endangered Species including information on how to make a Hedgehog footprint tunnel and how to identify nibbled nuts 

Field Studies Council have a great tracks and signs guide

Leave a comment