Monday, 5 September 2016

Scottish Wildcats And Mammal Conservation in Scotland

A Berkshsire Mammal Group Talk by:

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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