Opening the evening with a
display of exhibits, John introduced our largest carnivore with some
examples of road casualties, now stuffed and mounted for display,
including a handsome albino. Death on the road is a big problem, he
said – 50,000 are killed each year. They have defined routes and
will repeatedly cross roads at the same crossing points. Their sense
of smell is paramount, like that of a bloodhound – and though they
have excellent hearing and good eyesight, they have little awareness
of the dangers of the car. John then turned to his presentation.
He
started with pictures of the Group’s sett in Binfield. At that
date, despite the protection afforded badgers under the Wildlife &
Countryside Act, their setts were not covered. Setts would be
destroyed by pouring diesel and blocking them with soaked rags. At
Binfield a group was convened by a local lady, Shirley Davis, who
organised a campaign to save the long-established sett. The
developer eventually fenced off the site, erecting a close-boarded
fence around it. The site is only half a hectare, which is
insufficient for a colony to survive, so gates were fitted allowing
access to a nearby wood. As installed they were too narrow, and John
showed a photograph of a circular yellow stain around the opening
where the creatures had had to force their way through, the sandy
earth in their coats acting as paint in a living paint brush. The
gates have since been widened, and the site doubled with the
acquisition of additional land from a neighbouring garden.The site includes a tool shed for a lawn mower – as badgers prefer the shorter grass of grazing land – and a hide. John admitted (or boasted?) to have spent over 3000 hours watching badgers. The colony has also been filmed for television by Simon King.
Setts
John
then turned to describing the ecology of badgers in general, starting
with the typical disposition of setts within a territory. Setts will
have multiple entrances and be indicated by spoil heaps of sandy
earth, chalk or clay. Badgers can dig out a burrow in a night or
two. John displayed a 4kg flint which a badger had removed when
digging. Tunnels may extend down 3 metres, opening into a nest
chamber and on to the next. Ventilation shafts will rise straight
up, just breaking the surface. Ideally these will be sited on a bank
to achieve a chimney effect. Indeed in frosty weather the badgers’
breath can be seen rising into the air, betraying which chambers are
occupied. Old holes are large (large enough for John to enter) and
worn sooth from the badger’s preference for entering the burrow
backwards when dragging nesting material into the sett.
Badgers
sometimes share their sett with foxes. There are about 100 holes at
Binfield, but only about eight are used at a time, so occasionally
foxes occupy vacant holes on and, if not exactly welcomed, are at
least tolerated. But only if are quiet, however, otherwise even cubs
will chase the foxes away. (Foxes will sometimes reciprocate, but
frightening the badgers from behind and causing them to run and
hide.)
Artificial
setts are sometimes used. John illustrated this with a picture of a
concrete drainage pipe, in a roadside ditch, which was occupied for
three months. Others are deliberately placed as part of developers’
mitigation measures, such as when Legoland was built near Windsor, or
currently in Wokingham where a footpath has had to be closed.
Signs of
occupation
One sign of
badger occupation is the presence of clumps of hair on barbed wire
fences. They will be white with a dark band towards the white tip.
They are oval in cross section, so will click when rolled between
finger and thumb, and under a microscope it will seen that they are
hollow. Another sign is abandoned balls of bedding material, usually
grass or hay, but sometimes ivy or bluebell leaves.
Badgers have
favourite scratching posts. They drag their forepaws down the tree,
especially in damp weather when the wood is more receptive to the
application of sent. This they achieve by shuffling backwards and
raising their rears up the trunk above them, lifting their tales to
secrete their scent. Badgers are very territorial and this is a way
of marking their patch.
Paw prints are another sign. These are distinctive, though not easy to spot. Badgers have five, one-inch long, non-retractable claws, and therefore five pads. These are forward facing, in parallel, with a kidney-shaped palm behind, which is about 4.5 to 5 cm across. The rear paws are much less defined, and often obliterate the forepaw prints as the animal moves forward. John showed a marvellous picture of brown prints on a white background. Here leaves had fallen into a pond and an oily residue had built up on the water’s surface. When the pond froze over the oil lay on top of the ice and allowed clear impressions to be left in the snow when the badgers walked over it. Badger paths, while not distinctive, remain in use regardless of the weather, even in snow, and so provide an easily seen feature of their territory.
Another sign is
damage to lawns, usually those with weeds among the grass which
harbour the insects that badgers rely on for food: cranefly larvae
and summer chafer grubs. During the night then, they will grub
around, earning their old vernacular name “earth pig”.
Badgers
preferred food source is the lobworm, humbicus
terrestris, of which
they may eat between 100 and 200 a night. However, worms like warm
and wet conditions so the badger has to have other sources to
supplement its supply. This is especially true in the autumn, when
they will put on as much as 3kg to see them through the winter. They
will eat slugs (wiping them on the grass first, to remove the slime)
and snails (crunching the shells). They will break open dead wood
for larvae and insect eggs. They like brambles, elderberries (off
the ground) and hard fruit (they will climb trees for apples and
pears). Pausing for an anecdote, John referred to two badgers were
found dead in a pond in West Surrey. On investigation it appeared
they had eaten freely of apples in a nearby orchard; these had
fermented and the badgers had become intoxicated with fatal
consequences. Badgers will break into wasps’ nests and eat the
larvae from the honeycomb. They do get stung, however, and are not
immune, so will eat quickly and run. They enjoy eggs and will carry
them back to the vicinity of the sett to eat in safety.
Hygiene
Badgers are
very fussy about hygiene. They dig latrines on the edge of their
territory that all the family use, creating another alongside when
the first is full. Their gelatinous, mash-like excrement is
distinctive in appearance and smell. To establish occupancy and
measure their territory it is a surveying practice to introduce
coloured pellets into the badgers’ food, so the evidence will turn
up in the peripheral latrines. An annotated photograph illustrated
the contiguous territories of six neighbouring setts. Occasionally
nature supplies a similar effect, as illustrated by a photograph of a
latrine containing rose-hip tinted ordure!
Threat of
traffic
Protection
against road traffic is possible, though expensive. 2-metre tall,
heavy-duty, chain link fencing can be installed, burying the lower
part in a curve away from the road to deter any badgers from digging.
A break in the fence is permitted where there is a tunnel for their
use. On the M5 near Exeter there is even a tunnel slung below a
bridge over the motorway; it is used regularly and not just by
badgers, but by deer and hedgehogs too. Railways too are deadly
obstructions. On a line near Tonbridge, in Kent, 100 badgers were
killed in three months. Yet the third rail on an electrified line
need not be continuous, so provision for badger crossings can be made
if planned.
Reproduction
In April or May
badger watchers play ‘spot the nipple’ as lactation is often the
first sign of new cubs. Badgers undergo delayed implantation. The
sow might mate, but the fertilised egg ‘sleeps’ until the time is
propitious. She may gather three to six in a year, and then, if
undisturbed, enter a two-month gestation in December (though delay
can last up to 18 months.) The cubs are born in February, but not
seen above ground for about eight weeks. Two or three cubs per sow
is normal, but sometimes as many as four or five. At birth they are
only 12cm long, blind, with ears closed and weighing only 100g. When
they do make an appearance on the surface, it is usually to feed, as
badgers don’t take food underground. (They will take toys,
however, as suggested by the 150 golf balls in one sett near the
local links; tennis balls get shredded.) Their heads are fully grown
by August, but their bodies still smaller – 4kg, say, compared with
an adult of 10 – 12 kg. (The heaviest John has encountered was a
whopping 16kg.). Sexing is difficult without inspection, but John
showed photographs of the essentials. The male has an extra bone,
which traditionally gamekeepers used as a toggle on their jackets!
Rescue
Drawing to an
end John illustrated a number of injured and disorientated creatures
that the Binfield Group has helped over the years, including one from
Finchampstead that was taken to the animal hospital in Somerset run
by Pauline Kidner. Pauline tends to 50 to 70 cubs per annum,
building up small groups of healthy animals (with minimal human
intervention), for release back to the wild. Releases have to be
carefully managed: the cubs have to have two tests for bovine TB and
are chipped and tattooed. A release officer locates suitable sites –
and not in cull areas!
To conclude, John set out a family tree of the Binfield badgers, noting visiting badgers and known deaths, and identifying al the cubs born at the sett. The tree was based on sightings over 25 years, from 8 June 1990 onwards, the number of badgers varying from three in 1999, down to one at times, to six in 2013.
QUESTIONS
Are badgers becoming urban, like foxes?
No, quite the opposite. They are easily driven away be development. Badgers are easily frightened by sounds and running is their defence. Otherwise they remain very settled in their rural locations. The sett at Binfield has been in occupation for at least 145 years.Do they eat hedgehogs?
Yes, occasionally. Sometimes you can hear the hedgehogs scream. The badger will leave the spiney skin, which, as it dries, shrinks and inverts into a ball.Bovine TB
In a hotspot
only 1 in 7 is likely to have TB, so much of the culling is
unproductive.
What is the extent of the national population: numbers and distribution?
250,000 to
350,000, according to estimates at the census last held eight years
ago. The UK has the capacity for 600,000. They live in Scotland,
but not in wetlands (and much damage was caused by last year’s
flooding).
How big is a typical territory?
10 hectares
constitute a normal sized territory for a female with cubs – and a
football pitch is about 1.5 hectares – but it does depend on food
sources. There have been some at 100 hectares, but generally badgers
don’t like to go too far.
What is their average age?
3 years
(because of high mortality on the roads). They seldom live long
enough to become dominant. They can live to be 12 or 14, lifespan
being limited by wear to their teeth (as worms are full of grit).
Adults have 38 teeth on average, though individuals do vary.
Further information
There are 60
groups under the auspices of the Badger Trust, with at least one in
each county. Ernest Neal is the authoritative author on the subject.
attended that talk very interesting John knows his stuff loads of info,
ReplyDelete