ALL CREATURES GREAT & SMALL
Patrick Barkham celebrates the residents that make up Britain’s rich fauna. This month: otters
SLEEK AND GLISTENING, THE OTTER COILED ON THE BANK, before slipping away, re-entering the water ‘by melting’ as Ted Hughes once wrote. I’d hoped to catch a glimpse of our most elusive mammal by taking a canoe out onto the Norfolk Broads at 4am. After two freezing dawns, I returned home having caught nothing more than a cold. A few weeks later, one bright Sunday afternoon, I hired a small boat to chug noisily through a busy, suburban lake and there, five metres ahead, frolicked a magnificent, supposedly nocturnal, otter.
Otters are not obliging animals, and we love them all the more for it, but we would still marvel at their aquatic grace even if they were a quotidian part of our environment. When I took my children to the zoo, we stood agape by the otters for as long as we admired the giraffes. The otter is the only British mammal that can hold its own in a collection of the world’s most charismatic animals. Forty years ago, it was poignant to behold them in a zoo because this was a creature that had virtually vanished from our countryside. In 1978, belatedly, they were protected in law after hunting, habitat-loss and the disastrous build-up of heavy metals and other toxic pesticides in waterways caused them to teeter on the brink of extinction. Now, unexpectedly, otters are thriving once again, having returned to every English county by 2011. “Like a spirit level, its reappearance indicates that we are finding our balance with the wild,” writes Miriam Darlington in Otter Country.
It is no wonder that the Eurasian otter (Lutra lutra) has inspired some wonderful writing, from Henry Williamson’s Tarka the Otter to Gavin Maxwell’s Ring of Bright Water. Our only native species powers through the water at a metre per second in pursuit of eels and other fish. It is top of its food chain, with no natural predators, and yet its existence is a triumph against the odds. Living in chilly water, an otter’s metabolic motor is running around four and a half times the speed of a dog’s. In Being A Beast, the writer Charles Foster attempted to live like one, calculating he’d need to eat 88 Big Macs each day to keep pace. “These jangling, snarling, roaming, twitching bundles of ADHD,” as he put it, spend 18 hours asleep and six hours engaged in “frenetic killing”. Foster realised it was impossible to mimic their way of life. Zoologists find it so difficult to follow them in the wild that Britain’s leading researchers can only get up close when they are dead.
Cardiff University’s Otter Project has been collecting carcasses and conducting post-mortems since 1992. “Many people who have seen CSI would assume that it’s to establish the cause of death but that’s not our main function,” explains principal investigator Dr Elizabeth Chadwick. In most cases, cause of death is obvious – sadly many are found on the edge of busy roads. But Chadwick and her team use the bodies to discover many more insights into behaviour, lifestyle, population and the health of our waterways. The project began by collecting about a dozen carcasses a year; it is now sent 250, just one sign of the otter’s resurgence. “We’re
seeing them coming from areas where they haven’t been established before,” Chadwick says – particularly in south-east England.
Otters are sentinels of river health, and they bring good news. Levels of heavy metals and the other chemicals banned in the 1970s concentrate in the bodies of beasts at the top of the food chain but their appearance is decreasing in otters. “Contaminants have fallen but should they be there at all?” Chadwick asks. The Otter Project team has recently detected microbeads in the animals. Chadwick says these are “microscopic strands” and it isn’t believed they are causing direct harm, but they are analysing the data. Another trend revealed is the decline in what was once one of their diet staples: the eel. With fewer salmon and trout, too, otters are forced to eat less nourishing food such as crayfish, toads and frogs. In some areas, shortages may be contributing to otters stealing chickens and, most controversially, raiding recreational fishing lakes.
Ironically, it was anglers who first identified otters’ decline but, with numbers recovering to more than 10,000 in the UK, they have called for them to be culled. Saying the otter has no natural predator and must be controlled by humans misunderstands their ecology, argue scientists. The otter cannot wipe out fish populations; rather, its numbers are controlled by its prey; fewer fish, and otters will simply starve. In fact, says Chadwick, otters on a river are a sign of healthy ecosystem, and an abundance of fish. “You won’t get otter populations continuing to go up and up. They are naturally regulating,” she argues. “Fish populations will learn to adapt, and fish that have grown up in an area where there are no otters will behave differently to those where they are around.” Her point is vividly illustrated by a pike fisherman I meet on the Norfolk Broads. When otters first returned to his local river five years ago, he was often pulling up pike displaying otter-inflicted injuries. Now he rarely finds injured pike. Instead, he observes the fish behaving more cautiously, lurking on the riverbed to avoid them.
We, too, are having to adapt to a world where otters are commonplace, although they remain illusive, meaning that the sight of a V-shaped ripple in the water, followed by a beady eye and wet nose, will remain a rare pleasure for many years to come.