Some of Ireland's best-loved wild birds are fast disappearing - and the voracious American mink is to blame, say naturalists. Alan Murdoch investigates a wildlife detective story
Across a still Lough Arrow in Co Sligo, the view seems oddly dreamlike. A two-storey Victorian farmhouse on the distant far shore, whitewashed, pristine and silent, overlooks lush lawns sweeping down to the water's edge. Lichen-covered trees shade the lakeside below grazing sheep and isolated unpretentious bars where wiry farmers sit among generations of fishing memorabilia. A banked, shaded shore lined with lark's tongue ferns meanders around broad expanses of reeds rich with mayfly in midsummer, deserted wooded islands and the odd small boat. It should be heaven on water for wildfowl, a prime habitat for all manner of bird life. Yet in three days the only sightings are of four ducklings with their curiously petrified mother, and, a mile away, a solitary black moorhen.
Ireland's wild bird species - numbering about 312 - are falling sharply, and according to Birdwatch Ireland about 95 bird species are currently endangered. Alarm bells are sounding beyond the restrained murmurs in conservation circles. In the Dáil, Green Party leader Trevor Sargent wasted no time in naming one of the prime suspects. Proposing a ban on the farming of mink and of the silver and arctic fox, he warned: "The damage from escaped mink has led to the decimation of indigenous wildlife and serious problems on poultry farms."
There has been a mink-farming ban in Britain since January 2003, while fur farms are prohibited in Austria and are being phased out in Italy.
In the public debate that followed Sargent's comments, widespread losses of ducks, coots and moorhen on western lakes were cited. The Greens' anti-fur Bill won broad Opposition backing, but fears of alienating powerful farming interests within Fianna Fáil stopped it becoming law.
Escaped mink, now found along whole networks of Irish and British inland waterways, are not the native species found in mainland European countries but its American cousin, Mustela vison. First introduced into Britain in 1929 and Ireland in 1951, it was being bred at 58 Irish farms when regulation of the sector arrived in 1966. Just six farms remain.
NIALL HATCH, AN amiable lawyer who now represents feathered clients as Birdwatch Ireland's development officer says: "The main problem is they're voracious and versatile predators. They're not native and creatures here don't have any defence against them. If a fox comes along a duck leads its ducklings into water. But there's no defence against a mink. We do have stoats here, but they're nowhere near as aquatic as a mink would be. Mink is basically an aquatic animal that can also hunt on land." Mink's predatory instincts are most obvious where prey are artificially concentrated, as on poultry farms where the birds have no means of escape.
Hatch argues that like others in the mustela species - members of the weasel family - they have an innate "kill" instinct. "A lot of people attribute malice to them, but they're just doing what comes naturally. In an open environment they have to kill what they can because they don't know where the next meal is going to come from. So if a mink gets into a henhouse it's just slaughter." Mink "cache" surplus food in empty burrows, hedges or wet grassland - tell-tale remains of terns' even turn up in cavities in stone walls.
Of the ground-nesting birds, Hatch is particularly concerned about skylarks. "They're one of the species that have seen a big decline, partly due to changes in farming. They are targeted by feral cats but mink would find them very easy to take too, particularly the eggs. Then they're automatically affecting breeding."
Foxes and hooded crows also take eggs, a steady depletion that turns remaining nesting sites into tempting "honey pots" for predators.
The threat worsened with deliberate releases of mink from fur farms by, ironically, animal rights protesters. In August 1998 some 7,000 were let loose in the New Forest in England after a break-in at a farm at Ringwood, Hampshire. Many were recaptured, others shot to protect poultry. A month later protesters claimed to have released 1,000 more from a fur farm at Onneley, Staffordshire.
The then British agriculture minister, Elliott Morley, said the action showed "total disregard not only for the welfare of the mink themselves but also for wildlife attacked by escaped mink". An Animal Liberation Front statement claimed they had given them "a fighting chance of survival rather than a miserable existence ending in death by gas or electrocution."
In 2003 the tactic switched to Ireland with 1,000 mink released from a farm in Laois in the Irish midlands. The owners said most were rounded up.
RED O'HANLON SNR ran a mink farm north of Dublin three decades ago. He regards mink farming as no more cruel than other livestock rearing ignored by the anti-fur lobby. Like a hard-boiled veteran from an Annie Proulx story, he is scarcely home after an operation before heading off fishing.
He rejects wildlife observers' claims that farms closing down released some of their mink: "It's a total myth. Pelting out (killing and skinning) the farms' mink was the only way the operators could recover any money. Everything else was redundant. They got the value of all the pelts they could sell.
"Some escaped mink survived but the vast majority always died - they get killed on the roads. After 20 generations of farm breeding all they know is 'kill'. But they're almost as curious as a cat. I've known fishermen have a mink walk up to their bags and try to take the fish."
O'Hanlon witnessed Irish fur farms' peak five decades ago: "In the late 1950s, 100 breeding females would have been considered a big farm. Then word came through: "Look, there's money in this." People began to invest and large farms with 3,000 breeding females were set up. Back then, prices were extraordinary. A man could make as much from one pelt as from working for the county council for a week."
Operations were small-scale but profitable: "We had 100 per cent export tax relief. We didn't have to pay income tax. Dividends were also tax free," O'Hanlon recalls. By the 1980s profits fell as pelt prices collapsed from £25 to £3 each. Between 40 and 75 pelts are used in making a mink coat.
Far from being mistreated, O'Hanlon says that to obtain a perfect unmarked pelt "mink were kept in perfect luxury. Mine were fed on Christmas Day before I was - escaped animals usually came back looking for food". Wildlife experts shrink from the idea of mink as a single marauding menace, seeing instead the wider impact of environment, food supply, climate and predation behind falling wild bird numbers. Naturalists have become understandably weary of sensationalist items in local papers and tabloids - generally during the late summer dispersal season when young mink leave the family group and for a period are more visible. Such "mink plague" fe ars are, they insist, inaccurate. They do not multiply rapidly, while many young fall victim to territorial battles. Ground-nesting birds' decline has coincided with mink's recent spread in Ireland, but with much else besides.
After almost 33 years within Europe, Ireland's farmed landscape - 71 per cent of its land area - has a narrower crop range and more restricted habitats due to EU agricultural subsidies and more mechanised farming, though rural environmental protection schemes (REPS) support a limited restoration. Ten years' economic growth has seen towns and cities expand rapidly: after 150 years of human emigration the trend has reversed, with new Chinese, Polish, Lithuanian and others arriving.
In 2004, 77,000 new houses and apartments were completed in the Republic - half its houses were built in the last decade. Extra traffic, land drainage, coastal and river development also threaten wildlife habitats.
While recent extreme weather has also damaged nesting colonies, Dave Suddaby, a bird conservationist on Co Mayo's Mullet peninsula, notices more subtle climate changes affecting feeding: "With changing sea temperatures sand eels struggle to find their food source - plankton. So sand eels move on. You then get a knock-on effect on "klepto-parasitism" (where one bird steals food from another) with skuas that rely on terns to source the food.
"When the skua can't find terns with sand eels, it turns to different methods. So instead it takes adult or young seabirds if there are any, rather than fish discards or sand eels. The Arctic Skua in some areas in Shetland are now almost "quartering" (sector-hunting) harrier-like over the land looking for ground-nesting birds as alternative food."
Notwithstanding this, there are strong indications that mink are slowly fanning out and reaching more distant nesting sites across Ireland. Wildlife consultant Dr Chris Smal's landmark 1991 study of Ireland's feral mink calculated they would reach every part of the island within 20 years.
GALWAY CONSERVATION RANGER Ger O'Donnell has witnessed this inexorable march across his Connemara domain: "The first evidence comes from landowners keeping hens and pigeons - they're being decimated. We trapped our first mink here at Kylemore Abbey in 1996 - a nun reported 18 hens killed there." For poultry the risk is higher than from foxes - mink can slip through smaller holes and climb fences more easily. Confined birds, unlike fowl in the open, have no escape route and tend to be slaughtered en masse by the intruder.
O'Donnell adds: "In 1986 it was reckoned there were no mink west of Lough Corrib, so they've moved through our area in the last 10 years. Here in Connemara they're now out to Roundstone (west), and down to Rosmuck (south) and Renvyle (north west). The only place they haven't got to is Slyne Head" (offshore).
Naturalists recognise how drainage schemes, changes in farming and land use gradually eroded habitats over decades, reducing bird populations and restricting some to established colonial sites. They are equally aware that a new aquatic predator reaching those nesting sites is today accelerating that decline.
Mink thrive in the broad agricultural lands of Ireland's midlands' basin in mazes of uncharted ditches created by farm drainage. These feed slow-moving rivers including the Shannon, offering abundant food for fish and bird alike, while densely reeded shallows, dotted with flashes of yellow iris in summer, are ideal hunting territory for mink.
"There has been a huge decline in ground-nesting bird numbers, including ducks, of 50 to 80 per cent in some places," says Brian Caffrey a Birdwatch Ireland project worker based in Banagher on the Shannon Callows, a 50km stretch of seasonally-flooded wet grassland that is one of Ireland's prime habitats for waders.
"One of the strong possibilities is that predation is a significant factor. There is evidence of mink damage and they are sighted along the Callows." Merlin and hen harriers have also been seen during the waders' breeding season.
Caffrey monitors Ireland's once-common corncrake, reduced from 50,000 pairs in the 1950s to just 200-odd pairs today, mainly due to loss of habitat. A handful of other birds - linnet, sedge warbler, goldfinch and stonechat have increased.
Mink also hunt "colonial" sea birds such as terns, gulls and black guillemots. "Mink are now getting out to islands off the west coast - they have a range of about two to three miles [ which] they can swim easily," says Steven Newton.
Brian Caffrey agrees: "We can trap and control them and take them out of areas of high value. But if mink get into seabird colonies they can probably take every egg. Their behaviour seems to be different where they find an absolute bonanza in a concentrated bird colony. Then they eat what they can and then bring their young over.
"Island breeding areas on Lough Mask, Lough Ree and Lough Derg have all been affected; on Lough Corrib terns have been hit. The only change we know about that might explain this is that mink are now in those areas and can swim out to the islands. We are worried."
Evidence from Scotland shows bird numbers can recover if predators are removed. Mink control measures in the west of Scotland have reduced seabird losses and improved breeding success. A five-year project to eliminate mink from the Hebridian islands of the Uists and reduce their presence in Harris is now under way in the Western Isles.
Back on the eerily quiet waters of Lough Arrow some steps to control mink numbers have now been taken by locals. But long stretches of silent shoreline - all but bereft of bird life - tell their own story.