Terrestrial Mammals

Introduction

Mammals have filled the full range of niches available to them and may be specialist ….or generalist …. Ranging in size from the tiny pygmy shrew to the large red deer, wild mammals include species that walk, run, climb and even fly. Some are enigmatic and feature in our myths and legends. Others we think of as pests when their needs conflict with ours.

From the seed harvest rodents, to the browsers, such as deer, rabbits and hares, to carnivores, some specialist (weasel) and opportunistic (fox), to the highly specialised bats. In total in Wales there are about 45 species of free-ranging terrestrial mammals from 5 different Orders. They occupy most habitat types from the remote uplands to wooded valleys and aquatic environments such as rivers, streams and estuaries and some have adapted to share our dwellings.

Mammals adopt a range of survival strategies. Voles and rabbits are prolific breeders, but bats live for many years and produce at most one young per year. Dormice and bats hibernate when food supplies are low whilst squirrels do not hibernate, but can be less active in winter.

A number of mammals found in Wales are not native and have impacted on other native mammals, such as mink which escaped from fur farms and have had a devastating impact on the water vole, and grey squirrels (released by well-meaning Victorians and responsible for the decline of the red squirrel). Some mammals are extremely numerous (voles are estimated to number 75 million in Great Britain) and are regularly in contact with people within the houses (house mouse), gardens (moles) or in the wider countryside where some are considered to be a pest for one reason or another (e.g. fox). Others are very rare (barbastelle bat, pine marten) and declining (water vole) and hence of great conservation concern or unique to Wales (Skomer vole). Some have become extinct as a result of man’s activities with some people wishing for them to be reintroduced (beaver).

What they all have in common is that they give birth to live young which the mothers suckle with milk until they are able to fend for themselves. They are also a key part of the Welsh biodiversity. And they’re a good indicator of the health of our environment – the return of the otter to most rivers in Wales, for example, is a sign that our water courses are clean and provide plenty of fish and amphibians.

Sites of Special Scientific Interest (SSSI) are designated for important populations of otter, water voles and bat species. Otter are also a primary or qualifying feature of 13 Special Areas of Conservation (SAC)

The State of Mammals in Wales

The status of the 49 mammal species found in Wales was last comprehensively assessed in 1995. Published in October 2020, The State of Mammals in Walessummarises our current knowledge, reporting population sizes, geographical ranges, trends and, for native species, their Regional Red List status according to International Union for the Conservation of Nature (IUCN) standards.Beaver and wild boar were excluded from the assessment owing to uncertainty about their status in Wales. Most species had either increasing (26%) or stable (43%) ranges. All of the non-native species recently introduced to Wales have increased their geographical range. All naturalised species – that is, all those that have arrived since the formation of the English Channel but before the end of the 12th century – also have increased or stable ranges, with the exception of the black rat, which is now possibly extinct. The deer and carnivore groups include the most species with increasing ranges; indeed, all deer species in Wales are now found over larger areas than they were 20 years ago. The rodents, shrews, brown hare and hedgehog have largely stable ranges. The range trends for harvest mice and for most bats are unknown, because of radical changes in survey methodology over time, and, for many species, a general lack of monitoring information.

There are currently many opportunities for the conservation of mammals in Wales. The country remained a stronghold for polecats when they all but disappeared from the rest of the UK; current efforts to reinforce pine marten populations have been extremely successful; and Anglesey retains a key area for red squirrels. There are also significant populations of greater and lesser horseshoe bats, with evidence of an increasing northward spread, possibly reflecting changing climatic conditions. However, wildlife in Wales also faces challenges from the needs of expanding human populations, requirements for agriculture and forestry, and the presence of invasive non-native species. Through a series of case studies, The State of Mammals in Wales places the assessments of conservation status in context.

Mammal conservation in Wales

UK and international legislation protects our rarest mammals and UK and Local Biodiversity Action Plans (BAPs) guide actions for their conservation. A number of Welsh and UK organisations play an important role in mammal conservation and most are represented on the Wales Mammal Biodiversity Action Forum. These include Local Biodiversity Action Plan Partnerships, Local Environmental Record Centres, The British Association for Shooting and Conservation, The Bat Conservation Trust, The Mammal Society, Natural Resources Wales, The Vincent Wildlife Trust and The Wildlife Trusts of Wales, and Universities of Wales. See the Species Summary spreadsheet for a guide to which of Wales' mammals need conservation action.

The first official Red List for British Mammals, produced by the Mammal Society for Natural England, Natural Resources Wales, Scottish Natural Heritage (NatureScot) and the Joint Nature Conservation Committee, shows that 11 of the 47 mammals native to Britain are classified as being at imminent risk of extinction. Among those species listed as being at risk of extinction in Britain are the water vole, hedgehog, hazel dormouse, wildcat and the Grey long-eared bat. The European wolf is already extinct.

In Wales, the report shows that 1 in 3 species are threatened with extinction and 51% of mammal species need urgent action. Formerly widespread in Wales, red squirrel and water vole are assessed as endangered and hedgehog as vulnerable. For a full list of species on the Wales' list and their classification, download the summary report.

Contact

Wales Mammal Biodiversity Action Forum Secretariat

Liz Halliwell

BATS

Bats are fascinating creatures and they play an essential part in ecosystem functioning and in particular the control of nocturnal insects such as mosquitoes, midges, moths and beetles. Bats rely on a matrix of suitable habitats and quality of the environment- requiring places to forage, roost, breed and hibernate and their presence are indicators of a healthy environment.

Wales supports 15 of the 18 species of bat in the UK and there are 10 Special Areas of Conservation (SAC) where bats are either a primary or secondary feature of the SAC. All bat species and their roosts are legally protected in the UK and all bats are listed as European protected species under the Habitats Directive. In addition, 8 bat species are listed on the Priority Species list for Wales (Section 7 list)