Browsers and grazers
Colin Varndell concludes his look at Dorset's mammal species
Published in November ’15
The browsers and grazers of the mammalian world have mostly evolved to deal with being the prey species for the county’s carnivores. Feeding mainly on vegetation, many of them lead largely nocturnal lives, choosing to emerge from cover at dusk and retire soon after dawn. Several of the common herbivores have been introduced from other countries and continents by humans. On the other hand many of our native predators have been persecuted by man, some to extinction including the wolf and the lynx. Both of these predators would have preyed upon and therefore controlled populations of the larger herbivores, the deer.
Sika deer are native mammals of the Far East. The Japanese word pronounced ‘sika’ means simply deer. So, when we refer to these animals as ‘sika deer’ we are literally saying ‘deer deer’! Sika were first introduced to Brownsea Island in the mid 19th century. During very low tides some of these early released animals swam across to the mainland where they quickly established a breeding colony on the saltmarsh and heathlands of the Poole basin. Since that time, the population has expanded and spread right across Dorset and sika are now regularly recorded in the far south west of the county.
Roe deer are secretive and shy woodland mammals and the only truly native deer to be seen in Dorset. To watch or study roe deer is not easy, as they are wary animals. Fieldcraft, an understanding of the habits of roe are crucial ingredients of successful observation. Roe deer are both elegant and agile mammals and they lie up in woods and copses by day, emerging at dusk to feed on lush grasses. They have a tarnished reputation with gardeners, however, due to their liking for roses and other garden flowers.
The fallow herd in west Dorset is centred around Powerstock and Rampisham. These are the direct descendants of deer, thought to have been brought here by the Normans and are often referred to as ‘Old English fallow’. These large, secretive mammals are generally darker in colour than more recently introduced ‘park’ fallow. Due to escapes of park deer in west Dorset, hybrids between the two distinct races of this animal are now being seen, and it would appear that the Old English strain is now doomed to be lost, or at least adulterated.
Reeves’ or Chinese muntjac first became established in the English countryside after escaping from Woburn Park, Bedfordshire during the early 20th century. Although native to China and the Far East, conditions here appear to be very favourable for this medium, dog-sized deer and its population has grown and spread steadily south and west. It was first recorded in Dorset at Chetnole in 1970. It is rarely reported in the county, though, possibly due to its small size and its retiring habits. The Dorset Environmental Records Centre has just 47 records of muntjac up to 2012.
Squirrels are diurnal feeders as they have the ability to escape predation by quickly ascending trees. The red squirrel in Dorset declined to extinction except on three islands in Poole harbour. The loss of this animal from the countryside is thought to be largely due to the invasion of the more robust grey squirrel, which interloper came from North America.
The grey squirrel is not strictly an herbivore as it is known to take birds eggs and nestlings in the spring. However, the rest of the year it feeds mostly on vegetation and fruits and nuts.
The brown hare also may be seen during daylight hours, no doubt due to its advantage of acceleration and speed. The brown hare is common in Dorset, especially in the north and east of the county, where arable farming is more widely practised, but chalk downland is also a preferred habitat. Hares like to nibble fresh shoots of grass and cereal crops and can often be seen in newly sown fields.
Why rabbits appear in full sun can only be justified by their sheer number, with individual animals using the ‘it can’t possibly happen to me’ philosophy. Rabbits were brought into Britain by the Romans as a source of meat for human consumption. Once they had escaped into the wild they rapidly expanded as the climate and environmental conditions suited them. The rabbit population in Britain reached unsustainable proportions and, as a result, in the 1950s myxomatosis was unleashed, almost wiping out the British rabbit population. This loss of such a huge food source led also to the demise of many of their predators, especially the common buzzard and the polecat. Since that time, rabbit numbers have gradually increased as they appear to cope with the disease, although it is still present and does affect local populations. Certainly buzzard numbers have also fully recovered and we are now seeing polecats more often in the Dorset countryside.
The water vole population in Dorset underwent a dramatic decline following the arrival of American mink on Dorset’s waterways. Other factors – like pollution and loss of habitat – have contributed to the demise of this large, aquatic vole. The water vole prefers slow flowing water, with steep banks and plenty of lush vegetation. The spread of Indian balsam has choked vegetation on many stretches of river degrading the habitat for the water vole.
The wild boar of west Dorset are descendants of those animals which escaped from captivity where they were farmed for meat. This is a very secretive mammal and rarely seen during daylight hours. Their presence is obvious though, because where they occur, they churn over grassland and crops often inflicting damage to huge swathes of ground.
So it is that several herbivores have been introduced, on the other hand predators have been persecuted. However, there are fierce debates going on at present around the idea of reintroducing lynx to help control deer numbers. And who knows? It may not be many years before we see beavers patrolling Dorset’s waterways once again. ◗