Terrestrial mammals

Habitat  

Hedgehogs are unmistakeable as they’re the UK’s only spiny mammal. They’re found in a wide range of densely-vegetated habitats such as the edges of broadleaved woodland, hedgerows, gardens and urban greenspaces.  

Hedgehogs are generally solitary and are more active at night or in the early morning. They can travel 1-2 kms to feed on invertebrates such as beetles, worms, caterpillars, millipedes, leatherjackets and slugs. They also eat eggs and chicks, baby rodents, frogs, dead animals and fallen fruit. 

Hedgehogs have one litter of hoglets a year, in June or July. They hibernate from November to March or April (depending on the weather) in a nest made of leaves that’s hidden away under a bush, pile of dead wood (including bonfire sites) or in an abandoned burrow.  Their main predators are Badgers, and sometimes Foxes. 

Population 

Since 1995, the population of Hedgehogs in rural areas is thought to have declined by 73%. Hedgehogs in gardens and greenspaces are thought to be doing better, although they’re still in decline. They’re listed as threatened and are a UK priority species. 

Hedgehogs are particularly affected by loss and fragmentation of habitat. Flailing causes hedges to develop gappy bases that provide less cover. Many Hedgehogs are also killed crossing roads that separate their habitat. Fewer invertebrates also means they have less food.   

Hedgehogs are found across Devon, other than the high ground of Dartmoor and Exmoor. They could be present in any suitable habitat.    

As they’re largely active at night, Hedgehogs are not always seen. A good way to know if they’re present is to identify their tracks or droppings. Check the NBN atlas for records or contact DBRCDevon Biodiversity Records Centre (see links in Find out more below). 

Habitat  

Hazel Dormice live in the branches of trees and shrubs and, except for when they hibernate, rarely touch the ground. They can be found in a wide range of habitats that have good woody connectivity and lots of food. These include broadleaved woodland, hedges, heathland mosaics and scrubby grassland such as the Culm, Rhos pastures and coastal grasslands. They’ve also been seen in conifer woodlands, bramble patches and using bird feeders in gardens.     

Hedges provide critical connectivity, allowing the dormice to disperse into new habitats.  

Hazel Dormice are nocturnal. They feed on flowers, fruits, seeds, nuts (especially hazelnuts) and insects such as caterpillars and aphids. Important foodplants include hazel, oak, honeysuckle, bramble, willow, rowan and birch.  

Hazel Dormice have one or two litters a year, usually between May and September. In summer they use plants such as honeysuckle and grasses to weave nests which they hide in holes in trees, old bird nests, dense scrub and hedges. They generally don’t travel more than 70 m from their nest. 

Hazel Dormice build their hibernation nests at ground level, tucked among tree roots or under dead leaves, logs or moss.    

Population 

There has been a long-term decline in both the numbers and range of Hazel Dormice. The main reason for this is thought to be habitat loss and deterioration. As a result, their UK conservation status assessment is unfavourable. Hazel Dormice are classed as nationally threatened, are a UK priority species and are legally protected.  

Devon is a national stronghold for Hazel Dormice and they can be found in suitable habitat throughout the county. There are few records in parts of rural north, west and south Devon but this may be due to lack of survey (as most records come from surveys for developments) rather than lack of dormice.   

As Hazel Dormice are nocturnal they’re not easy to spot. One way is to look for hazelnuts that have a neat, smooth hole, caused by the dormice’s precise nibbling. Check the NBN atlas for records or contact DBRC (see links in Find out more below). 

Habitat

Pine Martens are members of the weasel family and are about the size of a small cat. They live in woodlands and are good tree climbers. They need areas with safe (they’re predated by foxes), sheltered places where they can rest and breed, known as dens. These are usually above ground level and can include tree cavities and hollow trees, abandoned squirrel dreys (nests) and old birds’ nests.

Pine Martens are largely carnivorous, eating voles, mice, Grey Squirrels, birds and insects. Fruits are an important part of their diet in the autumn. It isn’t yet known whether Pine Martens can suppress populations of Grey Squirrels, which are an invasive non-native species.

Pine Martens are mainly nocturnal, but sometimes come out during the day in the summer. They don’t hibernate but are less active during the winter.

Pine Martens are solitary (other than females with young) and have territories of between 1 km² and 10 km². They generally disperse up to 50 kms but have been known to travel up to 100 kms.

Population

Pine Martens were very common and widespread in Britain after the last Ice Age (around 10,000 years ago). The population declined drastically from the late 1800s due to loss of woodlands, hunting and persecution and they became extinct in most of England and Wales. They’re now one of Britain’s rarest mammals and are mainly found in the Scottish Highlands, North Wales and northern England. They’re being reintroduced to several areas.

Pine Martens are thought to have become extinct in Devon, Somerset and Cornwall between 1870 and 1880. They’re now being reintroduced to Dartmoor and Exmoor by the Two Moors Pine Marten Project. Animals were released on Dartmoor in autumn 2024. Pine Martens have also been recorded in north Devon and Exmoor but their origin unknown.

Habitat  

Harvest Mice are Europe’s smallest rodent, weighing only 6-9 g. They’re found anywhere that has abundant food and tall, tussocky grasses or reeds such as hedgerow corridors, tussocky grasslands, road verges, reedbeds, ditches and saltmarshes. They’re good climbers and live mostly in the stalk zone where they feed on seeds, berries and insects. They’re now rarely found in cereal crops as the gaps between stems are usually too wide for the mice to build their nests.    

Grass tussocks need to be at least a year old before they’re strong enough to support nests. Species that form tussocks include Cock’s Toot, Tufted Hair-grass, Reed Canary-grass, Reed Sweet-grass and Purple Moor-grass. Harvest Mice build their nests by splitting and weaving the leaves of grasses or reeds. The nests stay attached to the stem, generally over half way up. 

Harvest Mice usually have two to three litters a year, between May and October although they can breed into December. They do not hibernate. 

Population 

Due to a lack of surveys, little is known about the national population. The Mammal Society believes that Harvest Mouse numbers have declined nationally due to loss of habitat and they’re a UK priority species.  

The Devon Harvest Mouse Project is working with volunteers to find out more about the county’s population. Results to date show that they seem to be widespread across Devon but in low numbers and potentially declining.