Grey Squirrels
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. It is classed as an alien species & vermin.
It is illegal to release a trapped squirrel back into the wild.
In the wild the grey squirrel is diurnal and most active at dawn and dusk,
searching for available food. Compared with the red squirrel (which is
protected), it spends more time foraging and feeding on the ground than in
the trees. It is, however, very agile in the trees and can run along slender
twigs, leaping from tree to tree. The long, muscular hind legs and short front
legs help it to leap. The hind feet, longer than the front, are double-jointed
to help the squirrel scramble head first up and down the tree trunk. Sharp
claws are useful for gripping bark and the tail helps the squirrel to balance.
If a squirrel should fall, it can land safely from heights of about 9m (30
ft). They grey squirrel can leap more than 6 metres.
Squirrels have good eyesight and often sit upright on a vantage point to
look around them. They have a keen sense of smell too! They are clever & adaptable
which make a squirrel infestation hard to treat.
The grey squirrel builds itself a nest, or drey, about the size of a football,
made of twigs, often with the leaves still attached. It is built fairly
high in a tree and lined with dry grass, shredded bark, moss and feathers.
A summer drey is usually quite flimsy and lodged among small branches. Sometimes
the squirrel may make its nest in a hollow trunk or take over a rook's nest,
constructing a roof for it. A squirrel may build several dreys.
Although grey squirrels have a wide range of calls, they communicate mainly
through their tails, using them as a signalling device; they twitch their
tails if they are uneasy or suspicious. Regular routes are scent-marked
with urine and glandular secretions. Squirrels identify each other, and food,
by smell.
Winter: It is often during cold weather (or for nest sites) that squirrels
get into loft spaces. The grey squirrel does not hibernate and it cannot
store enough energy to survive for long periods without food. A larger, thicker
winter drey is built, usually on a strong branch close to the trunk, and
a squirrel will lie up in this in very cold weather, coming out now and then
to search out hidden stores of food. These stores of single nuts and other
items are buried in the ground in autumn, well spread out. They are found
by smell, rather than memory. Often they are not found at all and later
may grow, helping the dispersal of trees. As well as nuts they will eat young
birds & eggs. Winter dreys are often shared for warmth. As it sleeps,
the squirrel curls its tail around its body to act as a blanket.
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Breeding
In late winter, squirrels may be seen courting, one, or more, chattering
males chasing a female through the tree or across the ground. Females
can mate only twice a year, but males may mate at any time. After mating,
the male plays no part in the rearing of his young.
The female uses a winter drey as a maternity nest, or builds a new one.
She lines it with soft material and gives birth after a six week gestation
period (time between mating and birth), in March/April and perhaps again
in June/July.
An average litter has 3 babies but as many as 9 may be born. The mother
suckles the naked, blind young every three or four hours for several
weeks. They gradually grow fur, their eyes open and at about seven weeks
old they follow their mother out on to the branches. Gradually they start
to eat solid food and when their teeth are fully grown, at 10 weeks,
they give up suckling. A month or so later they move away from the nest
to build dreys of their own. If there are not too many squirrels in the
area, the young stay nearby; if it is crowded they will be chased away
to look for less crowded feeding areas.
Grey squirrels breed for the first time at a year old.
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