Wild Alphabet - B

Biodiversity
These days Biodiversity and its importance is on everyone’s lips, but what does it actually mean? Biodiversity is short for Biological Diversity, and is about the huge variety of life in the natural world. In its simplest form, Biodiversity is the huge number of species of plant and animal. Around 1.4 million species have been named and described, but many more await discovery - estimates vary between 6 million and 100 million!

Biodiversity can also describe the genetic diversity within a single species. Individuals all carry slightly different genes, and local populations are often genetically adapted to the place they live. This genetic variation is vitally important as it is the raw material of evolution. In the long term it may enable some species to change and adapt to our changing climate.

A final component of biodiversity is the wealth of different habitats, from forests to deserts, from mountains to the sea, all supporting different plants and animals.

Brimstone butterfly
The Brimstone butterfly, scientific name Gonepteryx rhamni, is one of our more common and easily recognised butterflies. It is a large butterfly with distinctively pointed wings, which often visits our woods and gardens. However the most obvious feature is its colour – the males are a bright sulphur yellow. The females are a slightly paler yellow.

The bluish-green green caterpillars feed on buckthorn and alder buckthorn. They pupate in late summer and the new adults will survive until next summer, making them one of our most long-lived butterflies. The adults over-winter hidden in woodlands, and are often the earliest butterflies seen on warm spring days.

There is a theory that the term "butterfly" originally referred to this species alone because of its butter yellow colouring. Another possible origin is the mediaeval myth that witches transformed into butterflies to steal butter.

Birch
The birch is fast-growing pioneer tree which readily colonise open ground. This, along with its ability to withstand cold conditions, high altitudes and poor soils, mean it would have been one of the first trees to cover the exposed landscapes as the glaciers retreated at the end of the last Ice Age. These days it is still a great coloniser, forests of young birch can appear with surprising speed on bare ground, roadsides and railway embankments.

The ability of Birch to spring up almost anywhere is partly due to the tiny seeds, which are produced in huge numbers and are small enough to be carried long distances on the wind. It is also very fast growing, reaching its full height in only 40 years. although it is also comparatively short-lived for a tree; few Birches survive more than 100 years.

In Britain we have two native birch trees: the Silver birch, scientific name Betula pendula and the Downy Birch Betula pubescens. The latter is mostly found in Scotland, all wild-growing birchs in Cheshire are B. pendula.

The silver birch is a very graceful tree, with its slender white trunk and long hanging twiggy branches. Common across Cheshire, large numbers can be seen on parts of the Peckforton and Beeston hills.

Buzzard
Like many birds of prey, in the past the buzzard has suffered from persecution. Its numbers were further reduced by organochlorine pesticide contamination in the 1950s and 1960s that affected their reproduction. At the same time myxomatosis decimated rabbit populations, their main food supply. This meant that for many years few Buzzards were seen in Cheshire.

Since then they have staged a comeback: in the last decade numbers have increased and buzzards are now a common sight in Cheshire. Look out for one or more Buzzards circling overhead with spread wings as they ride the thermals on a warm day. They can also be seen perched on fence-posts or telegraph poles – one of their hunting techniques is to wait on a perch, scanning the ground until they spot a rabbit or small rodent. Buzzards can be variable in colour, from dark brown to much paler individuals. There are generally paler patches on the underside of the wings, which vary in size, but the wingtips are dark. The tail is short, broad and barred. Superficially it resembles the much larger golden eagle (not found in Cheshire). When flying low you can often hear the distinctive ‘Kee-yaah’ cry.

Part of the Buzzards current success is their adaptability. Although they feed mainly on rabbits they will also take mice, voles, reptiles and carrion. In spring they have even been seen taking earthworms from bare fields. Our farmland, with its patchwork of open fields, hedgerows and woodlands makes ideal hunting territory, and there is even evidence of Buzzards moving into the edge of towns.

Bank vole
The bank vole is one of our commonest mammals, but rarely seen. With its blunt nose, small ears and chestnut brown fur it is appealing animal. Mostly vegetarian, the bank vole lives on buds, leaves, fruit, and the occasional insect. Despite the name, the bank vole lives in wood and hedgerow; anywhere there is shrub cover (its larger relative, the Field vole, does live in open fields and meadows).

Shy and retiring, the bank vole is never seen in the open, with good reason. It has many enemies, being preyed on by foxes, weasels, stoats, tawny owls, kestrels and others.

Good populations of bank voles, along with field voles and wood mice, are essential if we are to keep the charismatic larger predators. The Bank vole manages to maintain its numbers, despite all these predators, by breeding rapidly. A female bank vole can produce a litter of 4-5 young every 4 weeks through the summer. The young can start breeding themselves at a couple of months old. Just as well, as even if they avoid all the predators few bank voles survive more than 18 months.

This article was originally published in Cheshire Life magazine