Is the river otter a victim of its own success?

One of the biggest wildlife success stories of the past 30 years has to be the reintroduction of the river otter to the UK. When river quality started to improve after organochlorine farm chemicals were banned in the 1980s, the Otter Trust got to work releasing animals at selected sites across the country. Today, there are few river systems in Britain that haven’t been recolonised by them.

The flipside to this is that some river and countryside managers now say the programme has proved too successful because in places river otter numbers are out of control, causing problems for fish and other wildlife. Protected status makes the otter one of nature’s untouchables — a killer mustelid with a cast-iron public ‘aah’ rating.

If mink, stoats and weasels were even half as popular as this bigger cousin, shoots and gamekeepers would have real trouble on their hands. Where otters are concerned, the deep affection people have for them means that any call for a cull — no matter how limited or justified — would never ever get off the ground.

Early releases of the river otter

When the release scheme started to roll out, one of the rivers chosen by the trust was the little Gwash in Rutland, England’s smallest county. The Gwash fishing club — of which I was then a member — was asked if we’d mind them building a release pen on the upper reaches of our lease to house (from memory) a couple of dog otters and four or five bitches.

At a meeting, the river otter experts told us that after their release these highly territorial animals would hopefully settle, breed and any offspring then spread to other streams and rivers nearby. I remember being shown a large-scale map festooned with coloured pins plotting the likely dispersion paths across Leicestershire, Northamptonshire and Lincolnshire. The predictions proved spot on. Within a few years otters were popping up all over the place, establishing home in each of the three counties, and beyond.

The other thing I remember from that meeting was being told the hand-reared otters, when released, would have little fear of humans. That also proved true. Whenever these inquisitive animals spotted you in the water they’d scamper along the riverbank, dive into the pool you were fishing then roll playfully in front, just feet away. Getting so close to one felt like a privilege.

I saw them catch eels, trout and, once, even a rabbit. But being followed from one pool to another on a summer’s evening became tiresome. Some nights it was simply easier to pack up and go home than try to dodge them. Thankfully their friendliness didn’t last. Come springtime they’d learned the way of the wild and were rarely seen.

Since then I’ve encountered otters on numerous rivers and get the feeling that because they’re no longer persecuted, they seem less wary of humans than they once were. Last season I was fishing with BASC shooting coach Jim Wotherspoon and his wife, Maureen, on the Ness and an otter happily worked the water where we were, surfacing close to us before diving time and again into the torrent. It showed one last time, as it floated downstream, holding a 5lb grilse in its mouth and an expression that said: “That’s the way to do it!”

Cheeky

On another trip with Jim, this time to the Tweed, a cheeky otter swam behind us to pinch one of four lovely sea trout laid out on a shingle bank ‘guarded’ by my Labrador, Sam. Some deterrent. He didn’t even growl. And to add insult to injury, when it came to sharing the bag, Jim insisted it was my fish, not his, that made it back into the river.

As I’ve discovered, otters can pitch up almost anywhere, including here at home. One arrived via a tiny stream running through the farm. Why it should have followed what amounts to nothing more than a drainage ditch has had me baffled. Until now. I always knew an eccentric elderly neighbour downstream of us — recently deceased — was in the habit of nursing urban foxes back to health, then releasing them into the fields hereabout. They were fed on dead hens from a local chicken factory; stinking carcasses that countless carrion crows, magpies, rats and the contents of a nearby heronry also feasted on. At meal times the place looked like Jurassic Park.

It transpires the old chap also took in otter pup waifs and strays from time to time, then let them loose.

However, that doesn’t solve the legacy he left. It’s bad enough that his otter is now helping itself to scale-perfect carp from a pond close to the stream, but that’s just the start. Pheasants are being polished off close to the waterside, along with mallard nesting on the banks of the stream. The remains of both are scattered around the entrance to a disused drainage pipe.

Such losses are annoying but things could be a lot worse. Some years ago a friend in Fife had to call in a local gamekeeper to find out why he was losing scores of reared mallard on his three release ponds. The mystery was quickly solved: all the birds had died after having been pulled underwater and their beaks nipped off by … otters. He hasn’t reared another duck there since.

Hopefully, my losses are being caused by a single otter but with such a fish-rich food source at its disposal, I bet it won’t be long before others pitch up to share the feast. Perhaps there’s already more than one, which might explain why so few duckling are seen on either the stream, or the pond. To get a better idea of what might be happening I’ve now set up a couple of trail cameras. If I get any snaps I will share them here.