In reply to David Barratt:
On the basis of the following, I'd have said it sounds unlikely to be a wildcat.
No recorded sightings on Skye during the 2006-2008 survey period either, though of course that doesn't mean there aren't any.
http://www.snh.org.uk/pdfs/publications/naturallyscottish/wildcats.pdf
Habitat:
Wildcats live in habitats that satisfy two main requirements: shelter and food.
Woodlands and areas of dense gorse or juniper thickets provide shelter and resting places. Young forestry plantations in particular are an important habitat for wildcats because they are protected from grazing and support a high density of small mammal prey. Rocky areas also provide den shelters for female wildcats during the breeding season.
Wildcats require open patches of habitat, such as pastures or riparian areas, for hunting. However, when moving around their territories, they prefer to avoid open areas, using woodland or scrub and stream edges for cover.
Heavy snow makes it difficult for wildcats to move around or catch prey, and if there is deep snow on the ground for long periods, wildcats will move to forested areas or lower altitudes, where there is typically less snow cover.
The Scottish wildcat will venture to an altitude of around 800 metres but it is not generally found higher than 650 metres. It avoids heavily urbanized areas, areas of intense agriculture and exposed coasts.
The habitat used by the Scottish wildcat differs regionally. In the east of Scotland, wildcats prefer the margins of moorlands, pasturelands and woodlands, whereas in the west they prefer uplands with rough grazing and moorlands with limited pastures. These differences are due to the type of prey and cover available in these areas. For example, low rabbit densities in the west of Scotland mean that the wildcat needs to hunt voles and mice that are found in greater concentrations in areas of rough pasture, scrub and woodland edges.