Alicia
Leow-Dyke, 3 December 2015
Opening
the evening, Vice President of BMG, Melanie Orros, introduced Alicia
as a friend from their MSc course at Imperial College some years ago
and who has since spent time as a staff naturalist at the Aigas Field
Centre in the Highlands on beaver demonstration and wildcat breeding
projects – even appearing on television in Autumn
Watch. Alicia went
on to explain that the centre was built as a hunting lodge in the
Victorian period and after 1947 was used as a retirement home. Then
in the 1970s it was bought as a facility to encourage environmental
education. Aigas is located near Inverness, , with trees surrounding
the house, a loch nearby and extensive tracts of moorland beyond,
amounting to 800 acres. Her time there gave her the opportunity to
be involved with projects to conserve several species that are
characteristic of the Highlands.
Scottish Wildcats
Alicia
started with the Scottish Wildcat, or Felis
silvestris grampia,
which, since the extinction of the lynx, is the only naturally
occurring feline in the UK. Some regard it a sub-species of the
European Wildcat; others the local manifestation of a species common
throughout the continent. There are related species in Africa,
Middle East and Asia too. Wildcats were once found throughout
Scotland and the rest if the UK, and not just in the Highlands.
Slightly
larger than the domestic cat, males are around 8 kg; females, 3-5 kg.
Their diet is varied, consisting of mice, rats, voles – even
pheasants – but with a preponderance of rabbits.
The
females have two estrus cycles, each lasting 8 or 9 days in Dec-Feb
and May-July, though a second generally only if the first cycle has
been unproductive. Gestation lasts around 60-68 days and most
kittens are born in April or May. Litters vary between one and three
kittens, but more often or not are two. They live for 13 / 14 years,
though the oldest in captivity is 21.
They
face a number of largely man-made threats. Loss of habitat is
significant, particularly with the growth of plantations in the
twentieth century; exotic species and regular planting creates a
sterile monoculture, large, dead and dark, with few rocks and roots
in which to den. They have been hunted in the past, as their soft
fur was highly prized, and like other wildlife, they suffer from
traffic accidents. Natural predators (particularly of kittens)
include eagles and foxes, but the most characteristic threat is their
propensity to hybridise.
The
domestic cat derives from the North African wildcat, domesticated
8,000 to 10,000 years ago at a time coincident with the rise of
agriculture. They have since spread with human migration.
Differentiation between the domestic and wildcat is difficult.
Wildcat skulls will stand on end without falling over. The intestine
of the domestic cat is vastly longer than that of the wildcat –
maybe three or four times the length. And there are genetic
differences. But possibly easier are the distinctive markings of
their pelts. Wildcat stripes tend to be much finer than a hybrid or
domestic tabby, and the dorsal line in wildcats stops at the base of
the tail.
Today
there are perhaps 400 to 1000 wildcats in the wild, possibly as few
as 100 reasonably pure bred cats, and they constitute one of the
rarest mammals in the UK
Consequently
a captive breeding programme was established at Aigas in 2011, and
Alicia was its manager for four years. The first pair of cats
arrived in March 2011, from a scientist’s private breeding scheme
in Perthshire, and the second came a year later. A pair of kittens
was born in 2012 and another two in 2013. (Incidentally, kittens’
eyes are blue at first, turning yellowy green after a few weeks.)
The long-term aim, yet to be realised, is to release them in the
wild.
In
2013 a Wildcat Group was established with the support of Scottish
Natural Heritage and a six-year action plan was launched. 30-40
organisations are involved in various capacities: surveying habitat,
identifying and preparing release sites, monitoring populations,
neutering feral cats, promoting responsible cat ownership, and
breeding wildcats.
One
of the tasks is genetic testing. This can be on a variety of samples
– hair, faeces or blood – of which the latter is best. Taking a
leaf out of the Spanish programme for restoring the Iberian Lynx,
which is some way in advance of the wildcat programme, the test is
fulfilled by placing ticks in the cats’ dens which, when sated with
blood, drop off their host and constitute the sample! Many of the
wildcats tested have proved to 60-70% pure, with a proportion of
domestic cat. Finding 100% wildcats is looking increasingly
unlikely. What to do about hybridisation is a divisive issue,
however. Some conservationists are purists, other accept a degree of
hybridisation as healthy and a reflection of today’s reality.
Supplementing the Scottish population with European Wildcats from
elsewhere, say Turkey or the Levant, is seen as ‘Plan C’, because
maintaining a distinctly Scottish identity is thought important.
However, suitable European populations are being assessed for
possible future integration.
At
Aigas the breeding facilities allow for enrichment activity, with
aerial walkways, swings etc, to mimic conditions in the wild. The
food is natural – rabbits, venison – though males and females are
allowed to run together (which they wouldn’t normally, the males
being solitary) to maximise the opportunity for breeding. They even
have “starve days” to reflect the vagaries of hunting. The
kittens stay with their parents for a year, then the males and
females are separated to avoid in-breeding
QUESTIONS
The
talk was suspended briefly for an impromptu discussion, the answer to
some of the questions being incorporated, where applicable, in the
account above.
Can you handle them – are
they fierce?
You
don’t handle them except for testing and separation, as they will
spit, jump and use their claws freely. You need thick gloves and the
rapid administration of anaesthetic!
Is
it possible to establish for how long wildcats have hybridized with
domestic cats?
Yes,
over recent generations. A longer-term test is being developed in
Switzerland.
Does hybridization make a
difference to behaviour?
With
60-70% wildcat genes, there seems to be little difference between
pure and hybrid in terms of either fierceness or fertility.
Do they purr?
No.
They wail, caterwaul and hiss, and the kittens squeak.
Their characteristically
flattened ears suggest aggression. Do they prick up their ears?
Dificult
to say as they are usually aggressive in the presence of humans.
Have they been vaccinated at
Aigas?
No,
not yet
Is there any radio-tagging to
establish range or behavioural patterns?
No,
as the cats have not yet been released, but camera traps have given
an indication of the movement of wildcats. The full range is not
established and promises to be difficult, as wildcats keep on the
move, denning overnight and moving on (except when with kittens).
Are they arboreal?
They
do climb trees, and like to perch high up on a prominent branch, but
they don’t climb to the tops and don’t sleep in trees
Red Squirrels
Reddish
fur in summer and duller brown in winter, with characteristic ear
tufts, the Red Squirrel lives in coniferous and broadleaved woodland,
occupying 3-7 hectares or so. Its life span is 5-6 years. The
squirrel has a varied diet of cones, seeds, nuts and berries.
Nibbled pinecones are a telltale sign, with an uneaten ‘handle’
where they hold the cone. They stash food in Autumn, but their
memory isn’t good and they often forget where food is stored.
Red
Squirrels can be found throughout Europe, Siberia (except in the
Arctic north), Manchuria and Japan. They have been introduced to
Georgia in the Caucasus. In the UK, however, they have retreated in
the face of expansion by the incoming Grey Squirrel. In the 1940s
they were all over the country; Greys were only in the South East and
southern Midlands. Now Reds are found mostly in Scotland – the
Highlands, Southern Uplands, Cheviots – along with Anglesey,
Brownsea Island and the Isle of Wight. There are 120,000 Reds in
Scotland, with 15,000 in England (of which 60% in Northumberland.)
It
is a misconception that the Grey attacks the Red; the problem is more
to do with food resource competition and especially the spread of
squirrel pox, of which the Grey is a carrier and to which the Red is
susceptible. However, Reds do better in pine forests, as the Greys
are heavier and less able to make use of the flimsier branches of
coniferous trees. There is also an active policy of controlling
Greys in Scotland.
Pine Martens
Linked
to the above is the recovery of Pine Martens in Scotland (and to a
lesser extent, the rest of the UK. For some they amount to a
conservation tool for controlling Grey Squirrels. The population
recently was 3,500 in the UK and rising, with 3,000 or so in
Scotland. They are natural in the Highlands and, since 1990, are
reappearing in the borders with the odd one popping up in the Cheviot
Hills and North Yorkshire. In Wales the Vincent Wildlife Trust has
been active with the reintroduction of 20 animals and there has now
been a sighting in Shropshire. They also appear naturally in
Ireland.
Like
Red Squirrels, they have two moults and are redder in summer.
Significantly, each animal has specific markings on its distinctively
pale bid, making identification of individuals possible.
Pine
Martens eat berries, nuts, mammals, birds, eggs – even peanuts and
jam! They opportunistic and will enter buildings for food and
shelter. Alicia showed pictures of one such creature that had taken
up residence in a hide at Aigas in order to forage on peanuts.
Naturally Pine Martens live in rocks, caves, roots and up trees,
though now make use of next boxes devised by the Vincent Wildlife
Trust.
Badgers
There
are thought to be 250,000 in Britain, of which 25,000 are in
Scotland, but their behaviour is different in the north due to the
marginal habitat and the associated paucity of food. They tend to
live in smaller groups: 6 to a sett, rather than up to 25 in some
parts of England. At Aigas there are usually 3 or 4 per sett, with
several setts in the area. It is difficult to identify individuals,
except by the battle scars borne by some of males. Despite the lower
density of traffic in Scotland, there are appears to be no respite
for the badger, which all too often ends up as roadkill. However,
with no Bovine TB in Scotland, farmers offer much less of a threat to
badgers.
Beavers
There
have been various projects to reintroduce beavers to Scotland:
Knapdale and the River Tay, as well as Aigas in 2006.
The
herbivorous Castor
fiber – which,
contrary to widespread assumption, doesn’t eat fish! – is similar
to the smaller North American beaver and can be found across Eurasia
from Britain to Mongolia. In Europe it survived persecution mainly
in Scandinavia. Otherwise it was hunted to extinction – by C14th
in England and C16th
in Scotland – for their fur and medicinal qualities ( salicylic
acid). By 1900 only 2,000 or so were left in Europe, while now there
are 700,000! Indeed there are so many that in some jurisdictions –
Lithuania and Bavaria, for instance – hunting in October is
permitted to control numbers.
The
first reintroduction to Scotland was at Knapdale, were three or four
families were brought in from Norway. In 2010/11 a separate group of
beavers were found in the wild on the River Tay, numbering as many as
150-200 individuals at present. It isn’t known if they were
illegally released, or escaped, but there presence in an agricultural
district enables useful comparison with the forested habitat of
Knapdale. A decision by the Scottish government is due in 2015 on
whether to allow a more widespread reintroduction, though it looks
increasingly likely to be deferred to next year. Without human
intervention colonisation would be slow.
In
2015 the beaver was reintroduced to England too, with the discovery
of a pair on the River Otter in Devon (now with an additional three
youngsters). An initial decision to remove them as ‘non-native’
was rescinded in response to public opinion, on the condition they
were tested for atapeworm to which beavers are susceptible. They
were clear, so Defra permitted their continued presence on the Otter
for five years’ monitoring by the Devon Wildlife Trust. There are
plans for a reintroduction to Wales, too, with sites prepared for
future occupation.
QUESTIONS
How far would beavers spread?
They
are quite territorial and it depends on population pressure. If the
group is large, the 2-3 year olds will disperse some distances, but
if the group is small, with sufficient habitat for the resources it
needs, then the juveniles will remain close by. So in the five years
permitted in Devon they won’t go far.
How do they interact with
otters?
They
generally get along. The main risk is the vulnerability of
vole-sized beaver kits in May/June, as if an otter enters the lodge
he/she will kill them. Usually, however, the otter is curious,
teasing the beaver, which in turn simply ignores the attention.
DISCUSSION
Opening
up for discussion at the end of the talk, questions returned to the
Scottish Wildcat. Would there be conflict with the lynx should the
latter be reintroduced? It would be a cause for concern, but largely
for pressure on food resources (rabbits, especially), rather than on
the risk of predation. Other questions related to the preparation
for future release. Is there a risk of habituation? Yes, so
although the adults are for breeding and will not be released, the
kittens are left alone as much as possible. However, the lengths of
disguise are not resorted to with wildcats as with the bustard chicks
in Somerset; wildcats would not be fooled by a stripey onesie!
Edwin
A.R. Trout
Berkshire
Mammal Group
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