Wildlife in the Corridor

In Sussex we are lucky to find a diverse range of habitats, partly thanks to our geology. A combination of clay and greensand means the Weald is an important area for both ancient woodland and heathland. The South Downs are home to rare chalk grassland and streams. Freshwater rivers, floodplains and nationally important wetlands lead to the coast, home to many more important habitats such as salt marshes and kelp forests. These habitats are host to a diverse range of species. However, wildlife in Sussex is under threat and declining.

This is a pattern we are seeing around the world. We are facing a  global biodiversity crisis , every bit as serious as climate change. The UK is ranked as one of the most nature-depleted countries in the world, retaining only  half of our biodiversity .

"The UK has led the world in biodiversity loss"

Sadly, human activity has been the overwhelming cause of this loss. One of the major pressures facing species in the UK is habitat fragmentation. As human activity increases and land use changes, landscapes, even when superficially "green", become impenetrable barriers and cause species populations to become isolated and decline.

The growth of Sussex's seaside towns illustrates the scale of habitat fragmentation. The maps below show urban encroachment around Littlehampton between 1881 and 1963.

Today, urban encroachment has almost completely separated Sussex's marine and inland habitats, providing a barrier to species migrations and illustrating the importance of reconnecting these ecosystems. Land cover maps illustrate the dominance of "human landscapes" along the corridor. One of the major goals of Weald to Waves is to address this issue, and help to reverse habitat fragmentation in Sussex.

Weald to Waves has chosen a group of fifteen target species, to prioritise efforts and monitor the success of the corridor. This group was chosen for a range of reasons, including species currently declining, affected by habitat fragmentation or indicators of ecosystem health. This group are representative of the range of biodiversity within the project corridor.

Many of these species are rare. However, much of our wildlife is under threat and even many common and familiar species are declining rapidly. It is important that we all act to stop biodiversity loss.

(Erinaceus europaeus)

Conservation Status: Declining. Classed as Vulnerable to Extinction by the IUCN Red List for British Mammals. Protected under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Famous for their spines which protect them from predators, hedgehogs hibernate through the winter in dense vegetation and under hedgerows. In spring they emerge to forage for invertebrates such as earthworms and beetles. Hedgehogs are nocturnal and can regularly be seen visiting gardens at night, searching for food or a mate.

Habitat: Found across the UK in woodland, farmland and increasingly in urban areas. Therefore, hedgehog-friendly gardening is important for their recovery.

When to See Them: April to October.

UK Population size: Estimated at around 879,000 in 2018.

Pressures: Since the millennium, we have lost around half of our rural hedgehog population. Fragmentation and barriers to migration are a major threat to this species. Disappearing hedgerows, new developments, roads, and fences isolate green spaces and causing population declines. Hedgehogs are also regularly killed by cars and pesticides.

How to help hedgehogs: Improving connectivity; hedgehog-friendly gardening; citizen science monitoring. Visit the  Hedgehog Street website  to find out how you can help hedgehogs in your area.

(Vipera berus)

Conservation Status: Rapidly declining. Protected by the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: The UK’s only venomous snake, adders are surprisingly shy, and hunt small mammals, ground-nesting birds and lizards. Adders are cold-blooded, hibernating during the winter, and basking to raise their body temperature. When they emerge in spring the males “dance” to win a mate, and the females give birth to live young in late summer.

Habitat: Open habitats such as heathland, moorland and some woodland.

When to See Them: March to October, but be careful not to disturb this sensitive species!

UK Population Size: Populations at local adder sites are typically less than 10 individuals.

Pressures: Adders  could all but disappear from the UK by 2032 , following severe declines caused by habitat loss and fragmentation along with disturbance. Their distribution is not well mapped, but as populations become isolated, genetic health decreases leading to local extinctions. Adders are an indicator species, meaning that these declines are also likely to be occurring in other species relying on the same habitats.

How to help adders: Habitat restoration and citizen science monitoring. Visit the  Amphibian and Reptile Groups of the UK  website for advice on managing land for adders.

(Rana temporaria / Bufo bufo)

Conservation Status: While natterjack toads are famously threatened, sadly all of the UK's amphibian species are declining, and "common" is becoming a misnomer. The common toad is a Priority Species under the UK Post-2010 Biodiversity Framework.

About: These two species of amphibians breed in ponds in springtime, when toads undergo mass migrations to their breeding pools. They both feed in woodland, and grassland on invertebrates and through the winter hibernate in damp, dark conditions such as under log piles.

Habitat: Freshwater systems, including in wetland, grassland, woodland and gardens.

When to See Them: February to October.

Pressures: The loss of breeding ponds, particularly in gardens, is the primary cause for decline in these species. Severe fragmentation is also occurring as new developments and roads block migration routes. The RSPB's garden survey shows that between 2014 and 2018,  sightings of frogs declined by 17%, and toads by 30% . Over a 250,000 migrating toads are killed by cars each year and toad crossing patrols show a 68% decline in numbers from 1985 to 2016. Diseases are also an  increasing problem  for frogs.

How to help amphibians: Create a garden pond, or volunteer at roadside  Toad Patrols.  Visit the  Amphibian and Reptile Groups of the UK website  for advice on amphibian-friendly gardening, or the  Natural History Museum website  for a list of ways to help.

(Muscardinus avellanarius)

Conservation Status: Rare and declining. Classed as Vulnerable to Extinction by the IUCN Red List for British Mammals. Protected under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Famously sleepy, this golden-brown rodent is nocturnal and hibernates through the winter. Dormice are an arboreal species, meaning they spend most of their time in trees, rarely coming down to the ground. They forage on a range of flowering shrubs, invertebrates, blackberries and hazelnuts.

Habitat: Woodland, particularly new growth caused by coppicing, along with scrub and hedgerows.

UK Population Size: Around 879,000 remaining.

Pressures: Dormice rely on a continuous woodland canopy to disperse and are therefore severely affected by habitat loss. Declines in traditional woodland and hedgerow management has caused significant habitat loss and fragmentation.

How to help dormice: Hedgerow restoration and woodland management through traditional coppicing; citizen science monitoring. Visit the  Peoples Trust for Endangered Species’ website  for detailed guidance on how you can help dormice.

(Anguis fragilis)

Conservation Status: Declining. Protected under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Despite it’s snake-like appearance, the slow worm is a legless lizard. This species inhabits sheltered piles of vegetation, logs and compost heaps where they hunt for invertebrates. During the summer breeding season, males compete aggressively to mate. Females are ovoviviparous, laying eggs internally and eventually giving birth to live young. This species hibernates underground or in rotting wood through the winter.

Habitat: Widespread across Britain, in gardens, rough grassland, woodland, scrub, meadows and heathland.

When to See Them: March to October

Pressures: Although this species is common and widespread, it is threatened by habitat loss and fragmentation and is undergoing declines.

How to help slow worms: Visit the  Amphibian and Reptile Groups of the UK website  for advice on reptile-friendly gardening, or read the Amphibian and Reptile Conservation Trust’s  Reptile Habitat Management Handbook .

(Pipistrellus pipistrellus / Pipistrellus pygmaeus)

Conservation Status: Historic severe declines, but recently stable. Bats and their roosts are protected under the Wildlife and Countryside Act 1981. The soprano pipistrelle is a Priority Species under the UK Post-2010 Biodiversity Framework.

About: All of the UK's 18 bat species have been recorded in Sussex. Amongst the most widespread are common and soprano pipistrelles, only recognised as separate species in 1999. Both species roost in buildings, trees or bat boxes and use echolocation to hunt, feeding on up to 3,000 invertebrates per night. Dependant upon insect populations, bats are important indicators for ecosystem health.

Habitat: Widespread around the UK. in woodland, farmland and gardens. Woodland edges, hedgerows and freshwater habitats are are important for navigation and foraging.

When to See Them: April to October.

UK Population Size: 1,280,000 (common); 720,000 (soprano).

Pressures: Bats experienced severe declines across Europe in the 20th century due to persecution and changing land use. Pipistrelle populations reduced by around 55% since the 1960s. Since 1998, populations are believed to be steadily increasing, but have not recovered to their historic numbers. Many other UK bat species continue to decline.

Habitat fragmentation, caused by changing agricultural practices and new developments, continue to affect these species. Other factors include insect declines, chemical pollution from insecticides and timber treatment, light pollution and attacks from domestic cats.

How to help bats: habitat restoration and sustainable development are vital for bats. The  Bat Conservation Trust website  has a range of advice and support, including  advice for bat-friendly gardening . The  Natural History Museum website  also lists ways to help bats.

(Gryllus campestris)

Conservation Status: Declining, classed as Threatened. Protected under the Wildlife and Countryside Act 1981 and is a Section 41 Species of Principal Importance in England.

About: The singing of field crickets used to be a feature of heathlands, and a popular children's game was to tickle crickets to draw them out of their burrows. Now extremely rare, this species is flightless, around 2cm long, with chunky brown bodies. Males dig a south-facing burrow with a flattened hollow at the entrance for basking in the sun, and use a pattern of veins on their wings, known as harps, to sing to attract females.

Habitat: Grassy heathland in Sussex, Surrey, and Hampshire

Pressures: The field cricket is one of the UK’s most threatened species. Changes to forestry and agriculture led to the decline of its habitat, until by the 1980s the UK’s population was restricted to less than 100 individuals at a single site in West Sussex.

How to help field crickets: Heathland restoration, led by the  RSPB  as part of the  Back From the Brink project  from 2017 to 2021, have led to successful reintroductions of this species. However, there are still only six populations, and further habitat creation in Sussex is vital for the recovery of this species.

(Arvicola amphibius)

Conservation Status: Declining, classed as Endangered by the IUCN Red List for British Mammals. Protected under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Affectionately known as “Ratty” in the Kenneth Grahame's Wind in the Willows, the water vole lives in riverbank burrows. They feed on grasses and wetland plants, and frequent the same feeding sites where piles of nibbled stems can be found. Females defend riverbank territories 30-150m long and marked by latrines full of droppings, while males hold territories that overlap those of several females.

Habitat: The water vole inhabits rivers, streams, ditches, ponds, lakes, and wetlands. Once found in most freshwater systems across Britain, this species is still widespread but has been lost from 94% of these sites.

UK Population Size: Estimated at 132,000. The population dropped by around 90% between 1989 and 1998, and is continuing to decline.

Pressures: The water vole has undergone some of the most severe declines of any British mammal. Initially caused by the intensification of agriculture, the introduction of an invasive predator, the American mink, resulted in severe declines and local extinctions. In addition, water pollution impacts this species, directly through contaminated water bodies, and through eutrophication, with high nitrogen levels causing algal blooms and the decline of food plants.

How to help water voles: Habitat restoration and citizen science monitoring. Visit the  Peoples Trust for Endangered Species’ website   for guidance on how you can help.

(Halichoerus grypus)

Conservation Status: Grey seals have undergone a significant recovery in the UK, having been hunted to just 500 individuals by the early 20th century. Protected under the Wildlife and Countryside Act, 1981 and the Conservation of Seals Act 1970.

About: One of the UK's two seal species, grey seals spend most of their time at sea hunting fish. Seals haul out onto dry land to rest and give birth, sometimes in groups of hundreds of individuals.

Seals and kelp: The Sussex kelp forest has declined from 200km ²  to less than 6km ²  since 1987 and a new trawling bylaw is hoped to support the recovery of this important habitat. As top predators, seals provide an indicator of the health of marine ecosystems, such as the  Sussex Kelp Recovery Project . Kelp forest provides breeding grounds for fish, and in turn provides food for predators such as the grey seal.

Habitat: Found in marine habitats around the UK.

When to See Them: Grey seals can be spotted off the Sussex coastline all year round.

UK Population Size: Approximately 120,000 individuals, representing 95% of the European population and 40% of the global population.

Pressures: Marine pollution and entanglement in marine litter and ghost fishing gear.

How to help seals: Participate in a  beach clean , or pick up any litter you find the next time you visit the beach. Seals hauled out on dry land is normal, and it is important to avoid approaching or disturbing them, particularly by keeping dogs on a lead. If you find a seal you suspect is injured, call the  British Divers Marine Life Rescue .

(Zootoca vivipara)

Conservation Status: Declining. Protected under the Wildlife and Countryside Act, 1981. Priority Species under the UK Post-2010 Biodiversity Framework.

About: The UK’s most common reptile, this cold-blooded species basks in the sun to raise its body temperature before hunting small invertebrates. To survive the cold winter temperatures, common lizards hibernate under rocks or rotten wood.

Common lizards share some similarities with slow worms. As well as shedding their tails to escape predators, both species are viviparous, laying eggs internally and giving birth to live young.

Habitat: Widespread across Britain, in grassland, heathland and woodland.

When to See Them: March to October

Pressures: Although this species is common and widespread, it is threatened by habitat loss and fragmentation and is undergoing declines.

How to help lizards: Visit the  Amphibian and Reptile Groups of the UK website  for advice on reptile-friendly gardening, or read the Amphibian and Reptile Conservation Trust’s  Reptile Habitat Management Handbook .

(Streptopelia turtur)

Conservation Status: Declining, classified in the UK as Red under the Birds of Conservation Concern 4: the Red List for Birds (2021). Listed as Vulnerable to Extinction on the global IUCN Red List of Threatened Species. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Once common, many people will remember when the purring call of the turtle dove was an evocative sound of summer. Turtle doves mate for life and migrate each year from Sub-Saharan Africa, travelling over 5,000km to breed in Britain. However, today few people are lucky enough to see this species.

Habitat: Reliant on arable farmland for foraging, the turtle dove nests in hedgerows, scrub and woodland.

When to See Them: April to September.

UK Population Size: 3,600 breeding territories.

Pressures: The turtle dove is the UK’s fastest declining bird, with 98% of the population having been lost since 1970. This is a species on the brink of disappearing. The main pressures are changing agricultural practices, leading to a lack of seed and grain during the breeding season, and hunting by humans. Between two and four million birds are shot as they migration over countries around the Mediterranean each year.

How to help turtle doves: Habitat creation and citizen science monitoring. Visit the  Operation Turtle Dove website  to find out how to create habitats and help this species.

(Aglais urticae)

Conservation Status: Declining; while this is one of our most widespread butterflies, recent population declines, particularly in the South of England, mean this is a species of conservation concern.

About: This species is a familiar garden visitor, emerging from winter hibernation in spring to feed on nectar from a wide variety of flowers. Males establish temporary territories that they defend for a short period of time before moving on. Females lay their eggs on nettles, taking time to select optimal patches of young plants before laying up to 100 eggs.

Habitat: Able to thrive in a wide range of habitats in rural and urban areas.

When to see them: Commonly seen in gardens and countryside. Look out for caterpillars from May to August, and adults from March to October.

UK Population Size: Widespread and common

Pressures: The cause of a worrying decline in this species is not yet known. It is possible that this is due to the increasing populations of a parasitic fly, Sturmia bella, due to climate change. This fly lays its eggs on the foodplant of the small tortoiseshell and is eaten by the butterflies larvae. The fly grub then feeds on its host, eventually killing it.

How to help butterflies: Visit the  Butterfly Conservation website  to find out more about what you can do to help, such as gardening for pollinators.

(Anguilla anguilla)

Conservation Status: Declining and classed as Critically Endangered by the IUCN Red List of Threatened Species. Priority Species under the UK Post-2010 Biodiversity Framework.

About: Eels are a snake-like freshwater fish that can grow to over a metre long. They are predatory, feeding on fish and invertebrates in rivers and lakes around the UK. Eels famously leave our freshwater rivers to make an incredible migration, over 4,000 miles, to the Sargasso Sea to breed. They undergo physiological changes over this time, finally returning to our rivers as elvers (young eels) to develop.

Pressures: Another of the UK’s most threatened species. Overfishing, combined with pollution, habitat loss, damming rivers, and the effects of climate change on ocean currents, have led to the loss of around 95% of juvenile eel populations since 1980, with these factors continuing to cause declines.

How to help eels: Along with improving water quality, removing obstacles to migration, such as by installing eel passes on dams and weirs, can open new habitat areas along rivers and reduce habitat fragmentation. A number of organisations, are conducting projects around the UK such as the  Thames Catchment Community Eels Project .

For each species we have listed some of the most significant factors causing their decline. Explore our  Pressures map  to find out more about these factors in your area.