Across Carmarthenshire hedgerows provide a rich and varied wildlife habitat. They offer shelter, a supply of food, and a route linking different habitats along which wildlife can travel. If we look closely at a hedgerow we can see that in fact it provides for wildlife in many ways.
Hedgerows and Birds
The British Trust for Ornithology has carried out research demonstrating that hedgerows are particularly important for some of our farmland birds, including goldfinch, whitethroat, and greenfinch, while other species are more frequently associated with woodlands.
Hedges and woodlands appear to support different birds. The structure of a hedgerow will also influence the types of birds it supports - and a variety of hedgerow types will, in turn, support wide variety of birds.
Blackbirds, robins and wrens all prefer hedgerows that are thick right down to their base, whereas little owls like hedgerows with tall trees, in which to nest and from which to hunt. Hedgerows are an important hunting ground for Sparrowhawks, often seen flying fast and low alongside a hedge.
Tall grassy areas and brambles at the base of a hedgerow support high populations of small mammals making them good hunting places for barn owl. Fencing out of hedgerows, and placing the fence one pace from the base of the bank, achieves this goal.
Small mammals and insects
In Carmarthenshire, blackthorn hedgerows are crucial for the survival of the brown hairstreak butterfly. These butterflies lay their eggs on 3 and 4 year old blackthorn in late summer. When the leaves open in May it is on this plant that the caterpillar feeds.
Many small mammals feed and shelter in hedgerows. They will also use hedgerows when travelling from one area to another. Remove the hedgerows from a landscape and many of the small mammals will disappear as well.
Hedgerows are rich in insects and are consequently important feeding areas for bats.
It is vitally important that hedgerows supporting this butterfly are not trimmed every year, but that they are cut on a longer rotation, ideally every 3 or 4 years, so as to provide the necessary habitat.
Hedgerow trees add another dimension to the wildlife a hedgerow supports, adding a number of mini habitats not usually found in a hedgerow, such as standing dead wood, holes for nesting bird and bat roosts, mature bark which may support lichens, mosses, ferns, and ivy, as well as a huge canopy, important for a range of insects. These trees are extremely important features in the landscape, and hedgerow management should be designed to conserve those that are present and to allow the establishment of new hedgerow trees.