Despite the abundance of wildlife in Wales, few large species of mammal can still be found there. The largest land mammals in Wales are the two deer species: roe deer (Capreolus capreolus) and fallow deer (Dama dama). Roe deer are native to Great Britain and are found in central and northern Wales. Unlike other species of deer, roe deer are solitary and territorial. Fallow deer, although not native to Britain, were naturalized thousands of years ago. By far the most common deer species, fallow deer are found in rural and semi-urban areas of Wales. The European polecat (Mustela putorius) is a small, nocturnal carnivore of the Mustelidae family. Its range encompasses both urban and country environments, where it hunts birds, frogs and smaller rodents. Found in the same range as the European polecat is the red fox (Vulpes vulpes). Named for its reddish-brown coat, the red fox is one of the most common mammals in Wales, where it is sometimes considered a pest animal.
An amazing diversity of bird life nests in Wales for much of the year. Montagu's harrier (Circus pygargus) is a small, migratory raptor found near bodies of water and open, grassy plains. It is a rare species in Great Britain, although several nesting populations are known to exist in Wales. Red grouse (Lagopus lagopus scotica) was once a common bird, but it is now found only in the extreme northerly region of Wales. It is a favorite quarry of hunters, although hunting of red grouse is now restricted. King eider (Somateria spectabilis) is a large ocean duck known for its unusual plumage and head shape. With a black-and-white body, tan breast and multicolored head, king eider was once hunted extensively for its feathers. A distinctive facial crest gives king eider the appearance of having an unusually short beak.
Although hundreds of tree species are found in Wales, only a handful are native. Native trees, such as the wych elm (Ulmus glabra), suffer from disease and competition brought on by the introduction of exotic species. Few mature examples of wych elm exist in the wild anymore, having mostly been killed off by Dutch elm disease in the 20th century. One of Wales' most common tree species, the sessile oak (Quercus petraea) is found virtually everywhere in the region, from the coastal lowlands to the mountain foothills. Sometimes called the Welsh oak, images of this oak's leaves and acorns have appeared in the heraldry and artwork of Wales for hundreds of years. Holly (Ilex aquifolium) is one of the few native evergreen trees found in southern Wales. Associated with beech and oak woodlands, holly is a small tree with a slender pyramidal shape and spiny dark-green leaves. Apart from being ornamental, holly's berries are a favorite food source of thrushes and blackbirds.
Many of the flowering plants found in Wales are common throughout the rest of the United Kingdom, although several are restricted to the region. Snowdon lily (Lloydia serotina), named for Wales' highest mountain, is found only on the slopes of Mount Snowdon. Although the species is also found in North America, the Welsh variety has distinct genetic differences that have prompted botanists to reconsider its classification. It is a bulb-borne flower with a five-petalled, open shape and creamy white coloration veined with maroon lines. Cuckoo flower (Cardamine pratensis) is a herbaceous perennial found throughout Wales. The pale-pink, four-petalled flowers are widely cultivated by gardeners in the United Kingdom. Bog rosemary (Andromeda polifolia) is a small flowering shrub common in central Wales. True to its name, it grows in boggy peatlands and moorlands where it thrives in the acidic and consistently moist soil.
