Monday, 9 February 2009

UK ALIEN ANIMALS STUDY GROUP: Never outfox a fox

There seems to be a theme running threough the CFZ. After Beth's post about her pet fox Millie, we had Tim’s post on urban foxes, Dr. Holdsworth’s post on their biology, and now we have me looking at a very interesting alien animal indeed, the wily fox.

Vulpes vulpes is the UK’s local fox. The genus contains 12 species who are to be found on almost all continents (Antarctica is, as usual, an exception) and they all fill the same role: small adaptable carnivores who are adapted to eating any animal from the size of a typical insect, right up to a large game bird or lagomorph. Foxes moved up from the land bridge from Europe into the UK, but they never got up to the small islands off the coast of Scotland. However, it seems they may well have found a way.

Thanks to the very helpful Glen Vaudrey, (soon to be CFZ Cheshire rep) we have the news that it looks like the red fox has found its way to the Outer Hebrides. Although no reports have been certified by Scottish National Heritage, between December 05 and January 07, with 2 reports before this, 12 reports of foxes have been reported. These come from the Islands Lewis, Harris, Benbecula, and South Uist. I did try to upload an image of the area, but it was too small to see the Island's names, so I have not. But, the reports nearly span the entire area of the Outer Hebrides, from Lewis in the north to South Uist near the South. The sheer span of reports is what settles this matter for me; we have sightings of adults, sightings of cubs, 2 reports of droppings, a dog who acted strangely in response to smells, and finally, that a fox was seen for 15 minutes by a professional mammal biologist. The reports I was sent are repeated below:

Dec-05 Tolsta, Lewis = Report of fox seen on croft
Dec-05 Gress, Lewis = Report of glimpse of fox by road side
18-Feb-06 Urgha, Harris = Report of fox watched for 15 mins by professional mammal biologist
2005 Barvas road, Lewis = Note on local paper about someone seeing a fox cross Barvas road
2005 Clisham, Harris = Letter in Stornoway Gazette reporting seeing fox cubs beside a loch
28-May-06 Tong, Lewis = Report of fox seen in garden
May-06 Galson, Lewis = Report of fox droppings, and a dog behaving in a strange manner in response to smells
06-Jun-06 Daliburgh, S Uist = Report of fox seen crossing road in the evening
06-Jun-06 Liniclate, Benbecula = Report of fox
27-Jun-06 Tolsta, Lewis = Report of fox droppings by Garry Bridge
Aug-06 Uig, Lewis = Seen on road somewhere between Gisla and Grimersta
31-Aug-06 Arnol, Lewis = Seen near fish farm
Dec-06 Gress, Lewis = Seen on a croft
Jan-07 Aline, Lewis = Fox seen in trees by the road

This is a lot of reports, most of which seem viable. As one would expect from foxes, there are reports from a number of different areas, notably including a garden (typical!). 10 of the reports predictably come from the largest Island, Lewis. Now for the real question, how did they get there?

Tough to answer that is. If this was a geological report from 3 million years in the future, and we were looking at fossils not live animals, we could confidentially say that they got to the islands by using the sea as a vector and were washed out to sea, possibly via a flood, where their swimming and the action of the current swept them over to the islands.
The distance from the Inner Hebrides to the Outer Hebrides, is about 25kms, not too far for animals to be swept. This may have taken a few days and a lot of luck, but the fox may well have got there still breathing. Thin, but alive. All it would take is a male and female to be washed up within a few years (their lifespan is only about 3 years in the wild) and you probably have a breeding population. Better than that, a pregnant female is washed over and then you have multiple foxes.

However, we are not dealing with geological time; this is “real” time. I am not so sure that this a long enough period of time for this theory to work, although we must not dismiss it. It seems that humans are a more likely vector, either deliberately or by accident. They could have been released by someone bringing a few over from the mainland, or in the hold of a ship. I am really not sure what to make of it! David MacLennan from Scottish National Heritage says “It’s very difficult to say how they got here, because we don't even know if they are here!” and I must say I agree with him in the main. It seems highly probable that they are there, but more evidence is required. Photos however, are to easily faked by photographing a fox from the mainland, so a pinch of salt may be required if one comes to light.

WIKIPEDIA FACT FILE: Today, the Red Fox has thje widest range of any carnivore - range spanning most of North America and Eurasia, southern Australia, and with several populations in North Africa. In Australia the Red Fox is an introduced species and a serious conservation problem. Introduction occurred about 1850, for recreational fox hunting, In North America the Red Fox is native in boreal regions, introduced in temperate regions. There is a recent fossil record of Red Foxes in boreal North America, and one subspecies of these native boreal foxes extends south in the Rocky Mountains. In temperate North America, Red Foxes are derived from European Red Foxes, which were introduced into the Southeastern United States around 1650-1750 for fox hunting, and from there to California for the fur trade. The first introduction is attributed to Robert Brooke, Sr., who is said to have imported 24 Red Foxes from England. The introduced European Red Fox may have interbred with the scarce indigenous population to produce a hybrid population.

Three subspecies of Red Fox are found in India: Vulpes vulpes montana (the Tibetan Red Fox), found in Ladakh and the Himalayas, Vulpes vulpes griffithi (the Kashmir Fox) found in Jammu and Kashmir less the Ladakh sector, and Vulpes vulpes pusilla (the Desert Fox) found in the Thar Desert of Rajasthan and in Kutch, Gujarat. A subspecies, the Japanese Red Fox (Vulpes vulpes japonica) migrated from India to China and eventually to Japan.




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