Bank vole (Clethrionomys glareolus)
The bank vole has a small, stocky body and a blunt, rounded muzzle. The upperparts may be yellowish, reddish or brown in colour, the flanks are greyish and the rump is whitish-grey. The short tail is usually slightly bushy at the tip.
Bank voles are widespread across mainland Britain, but are absent from some offshore islands. Life span They live for up to 18
months.

Red squirrel (Sciurus vulgaris)
The red squirrel is native to Britain, but its future is increasingly uncertain as the introduced American grey squirrel expands its range across the mainland. There are estimated to be only 140,000 red squirrels left in Britain, with over 2.5 million greys. The main threats to the survival of the reds are the increasing number of grey squirrels, disease (squirrel poxvirus) and road traffic. Greys can feed more efficiently in broadleaved woodlands and can survive at densities of up to 8 per hectare. The density of reds is up to 1 per hectare in broadleaved woodland but can be as low as 0.1 per hectare in coniferous woodland.

Grey Squirrel (Sciurus carolinensis)
Native to North America. Introduced to Great
Britain, Ireland and South Africa. The grey squirrel was introduced to Great Britain in the mid-19th century and after many releases it began to increase dramatically at the beginning of this century, mainly spreading from Woburn Park, Bedfordshire. It is now one of Britain's most well-known and frequently seen mammals,
being much more common than the native red
squirrel.

Eggs of a Butterfly
The Egg or Ovum. The shape of butterfly eggs is remarkably variable. The examples below show some recurring forms but there are many others, for example swallowtail eggs are smooth and spherical. There is some consistency of shape between closely related species. The egg consists of an outer casing, or chorion, inside which is the females fertilised ovum. There is always a minute opening, the micropyle, which is visible as a small pit at the top of some eggs. This structure allows the male sperm to fertilise the egg and probably allows the developing embryo to breathe.

American Mink (Mustela vison)
The mink is a medium-sized member of the weasel family. The first American mink were brought to British fur farms in 1929 and all wild mink in Britain today are descendants of escapees. The natural wild colouring is a glossy dark brown, appearing almost black in some light.
Commercial farming selectively bred much paler colours, hence most of those in the wild in Britain are a lighter brown. Mink spend up to 80% of their time in their dens, sleeping, grooming and eating food they have carried home. Frequently found near water, they are often mistaken for otters, although mink are in fact considerably smaller.
Mink are responsible for the decimation of the water vole population because they are small enough to follow their prey down its burrow.

Eurasian Otter (Lutra lutra)
Biological/outstanding features
SIZE: 1-1.3m
WEIGHT: 7-9 kg
DIET: Fish (80%), birds, small mammals, frogs
GESTATION: 9 weeks
OFFSPRING: 2-3 cubs
HOME RANGE: 20-30 km river 3-4 km coast
PHYSICAL FEATURES: Short limbs, webbed feet and claws - Sensitive whiskers around snout to help detect prey - 2 layers of fur: a thick waterproof outer one and a warm inner one.
SPECIAL ABILITIES: The Eurasian otter has an acute sense of sight, smell and hearing. The eyes are placed high on the head so that it can see when the rest of the body is below water.
 Although the otter is an exceptionally good swimmer and fish catcher, it can only hold its breath for 20 seconds as it dives for its prey. Otters are the only amphibious members of the weasel family.  To survive in the wild, however, is not easy, particularly for a Carnivore and the otter will be lucky to reach the age of 4. However, there have been instances of otters living from 8-12 years, although possibly only one or two in a hundred will survive until this sort of age.