Spring 2002 No. 12

Page 4

On the Tail (a very long one) of the Southern River Otter…

The Southern River Otter, Lontra provocax or ‘Huillin’ has a limited distribution being found only in Southern Chile and just two sites in Argentina. It is similar in looks to our European Otter Lutra lutra, it is roughly the same size but has a slightly more domed head and a longer tail.

The Southern River Otter was first surveyed by Gonzalo Medina a number of years ago. The population’s range had nearly halved in a hundred years but no one knew why, in fact no one knew any thing much about the Southern River Otter, its behaviour was assumed to be similar to the European Otter but was this true?

Gonzalo continued to work with the otters and set up the research-driven Southern River Otter Project. This project has established that Southern River Otters have a particular liking for crayfish and other crustaceans rather than eels which appears to have meant that they have rather more specific habitat requirements than our European Otter.

The project is currently focused on the northern edge of the Southern River Otter’s present range. This area and below has only been colonised by humans on a large-scale in the last hundred years and it has brought sudden disturbance and rapid habitat destruction. There is not the wide public support for nature conservation in Chile as in England. However where we have destroyed all of our wilderness leaving small pockets of semi-wild places Chile still has some left, although it is being destroyed at an appalling rate.

It was very upsetting to see that most of the surrounding Southern Beech forest where we were working had been set fire to and re-planted with conifers. I found it quite frustrating that there is a programme of river canalisation going on in Chile when it has been shown in Europe that some of these schemes don’t even work and cause greater flooding further downstream. It is a shame that countries like Chile want to be so like the Western World that they merely copy us rather than learning from our mistakes!

Alison Washbrook of the Avon Wildlife Trust and myself gained a Millennium Awards Grant to go out, meet Gonzalo, learn more about the project and participate in the Radio-tracking programme that is happening at the moment. The project is also involved in active conservation work and we were keen to compare Gonzalo’s approach to our own. Many of the methods were very similar. Landowner advice is seen as particularly important and some money is available to fence off river banks so that farming does not happen to the edge of the water. Awareness is raised amongst farmers and also local schools. What is different is the location and the facts available.

The radio-tracking experiments aim to find out what the otters’ home ranges are and what habitat types are particularly important to the Southern River Otters so these can be protected for the future. There was a group of us staying at a camp and we helped Gonzalo and Rene to locate and plot the movements of three otters ‘Rey’ – a male (King of the River), ‘Linde’ – meaning beautiful, a female and ‘Princess’ – another female. A fourth otter ‘Rayen’ – meaning flower was also supposed to be tracked; unfortunately she could not be located and we were unsure of her fate. The great benefit for me in radio-tracking is that as you can detect where the otters are you are more likely to see them and indeed I first saw Linde while waiting with ten other people on a bridge amongst some swamp-wood or ‘Hualve’.

I lay face-down with my head in a gap between two planks. I saw Rene who was monitoring her movements signal that she was close by and I looked down. I could see large ripples behind me and thought ‘Oh I think that’s her’ she swam out ‘Oh there she is’. I felt quite calm and matter-of-fact. She swam directly under me, I looked at her but I’m pretty sure she never saw me – it felt like time was standing still. Someone took a photo with a flash, she dived instantly then, but amazingly she came back, sat amongst the in-channel bushes and hissed at us. It was then that it hit me that I was really watching the otter I reached for my camera but I was shaking so much I couldn’t really do anything. She kept diving then sitting amongst the Hualve hissing – what a feisty female!

I now have a permanent image of Linde in my brain. I do hope that I am not one of the last people to see a Southern River Otter as they continue to decline with the destruction of their habitat. Recently Gonzalo submitted some evidence for an Environmental Impact Assessment on a section of river due to be canalised. The authorities took on board the evidence and dug an extra channel rather than canalise the river through what is an important otter area. Lets hope that this sort of co-operation continues in the future so that Linde, Rey, Princess and their kind continues to hunt and play within the rivers of Chile.

Bronwen Bruce