Winter 2002 No. 15

Page 5

Wandering Otters

In Tarka the Otter Henry Williamson describes an old dog otter – Marland Jimmy. ‘His wander years were past: he had killed salmon in the Severn, eaten pollock on the rocks of Portland Bill and lampreys in the Exe. Now he dwelled among the reeds and rushes of the White Clay Pits.’

Williamson based most of his descriptions of otter behaviour on close personal observation but it is clear that such an epic journey, even during the course of an otter’s lifetime, could be nothing more than the workings of a vivid literary imagination.

However it does raise the question of just how far will otters travel. It is well known that male otters can have a territory of over fifteen kilometres along a particular stretch of river and its tributaries. This is the area within which they will hunt and fish and look for a mate. As the otter population increases young male otters need to disperse in search of their own territories.

Last May a dead otter was found just over the Wiltshire border beside the road near the village of Tollard Royal. The Environment Agency arranged for a post-mortem to be carried out as they always do when a dead otter is recovered in this way. The otter turned out to be a healthy young male with injuries which suggested that it had been hit by a car.

One question which the post-mortem couldn’t answer is what was the otter doing there so far from a river or stream. The nearest watercourse is the Gussage Brook, a tributary of the river Allen which meets the Stour at Wimborne. It rises at Farnham, some five kilometres from the location where the dead otter was found but its upper reaches are dry for much of the year turning into nothing more than a muddy ditch. However spraint has been found further downstream, near the confluence with the Allen. So one possibility is that this was a young male otter venturing into the unknown in search of his own territory.

Otters can travel considerable distances over land but just how far they will travel is still not known. In the past otters have been tracked across snow-covered ground for many kilometres. Currently radio-tracking of otters is not considered to be an acceptable option for monitoring their movements but DNA analysis of spraint in Hampshire and Devon is beginning to shed fresh light on otter movements within a particular area.

What is significant about this particular incident is that without it we would have no idea that an otter had travelled to this unlikely area. The work of the Dorset Otter Group has produced an impressive amount of valuable information on Dorset’s otter population but the tracks and spraint which we find and record can be nothing more than static points on the map and we only monitor those places where we think we will find otters.

One intriguing question is just how far this particular otter would have travelled if it hadn’t encountered a larger predatory mammal travelling along in a metal box. Six kilometres to the north, through woodland and over the watershed of the chalk downs, lie the valleys in which the river Ebble and the tributaries of the Nadder begin their journey east to the Avon. Mark Satinet of the Wiltshire Wildlife Trust has told me that otters have been recorded from both these rivers. Would this particular otter have travelled such a distance? We will never know.

Comment from Potter: Why couldn’t it have been a Wiltshire otter travelling south?

My reply: Get back in your holt.

Peter Irvine

Food for thought …

The UK biodiversity Action Plan’s goal is to see, by 2010, otters breeding in all the areas where they were before the 1960's. And, given how well otters are doing, there is a strong chance that what we once thought would be a miracle, will happen. Ironically if it does, the otter will be taken off Schedule 5 of the Wildlife and Countryside Act 1981, and hunting will be technically legal again.

Rosamund Kidman Cox
BBC Wildlife Magazine December 2002