Wild boar (Sus scrofa) were once native to Great Britain but became extinct some 300 years ago. However, following escapes or deliberate releases from wild boar farms or animal collections, they have now established breeding populations in the wild. The main colonies are in Kent/East Sussex, Dorset/Devon and the Forest of Dean, with regular reports of further releases and sightings which have included areas of Wales and Scotland.
The wild boar is the ancestor of the domestic pig and since the first escapes there have been reports of hybridisation, especially in the vicinity of outdoor pig-rearing units. The actual scale of this problem is unknown but hybrids will typically display a shorter snout with a dished profile, smaller shoulders, larger ears, a curly tail and the absence of thick brown under-fur. Purebred European boar are likely to be longer in the leg, typically dark in colour with a coarse bristly coat, a large head, long straight snout, relatively flattened body and a straight tail.
Adult males weigh in the region of 120 to 150kg and will stand 70 to 90cm at the shoulder with an overall body length of approximately 150cm. These animals will possess sharp tusks which will grow progressively from two years of age. Females are about 30 per cent lighter in weight than males and both sexes have a mane of longer hair running down their backs. Piglets are red-brown to ochre coloured, with yellowish longitudinal stripes for the first four to five months. This coat is then moulted to a uniform red-brown fur which in turn develops into the adult coat at about 10 to 12 months.
With good feeding, both sexes can mature in under a year. Sows can come into heat between October and May but the height of the season is between November and January. Subordinate females coming into season may be synchronised with the dominant sow. Gestation is three months, three weeks, three days. They are prolific and regular breeders, with litter sizes increasing with age. When food is abundant, sows can produce two litters a year and this poses issues over the practicality of a close season. They have the potential for very rapid population growth if not actively managed. Defra has assessed the population in England to be 500 -1,000 animals but those who are actively managing boar consider this to be a gross underestimate.