Natterjack toads under threat from rising oceans

ANOTHER LIFE:THE WORST of the stormy days shrouded the ocean in spray, so that, beyond the heaped-up terraces of surf, explosions of waves at the islands and reefs blazed and faded, white on grey, in a distant silence all their own. The tide seethed across the strand to worry at the new rampart of rocks my neighbour has laid to shield his fields. The fences there have been moved back again and again, leaving new, ragged pelmets of turf to sag above the sand.

All along the west, soft shores are crumbling. Down in Kerry, the swells surging into Tralee Bay are biting at the coast road to Fenit harbour, where Liebherr ships out its big cranes. The county council has already spent the money it had for coastal protection. Some €4 million went at the head of Dingle Bay, on the other side of the peninsula, where the great barrier of Inch Strand takes the brunt of the waves. Rossbeigh peninsula reaches out towards it from the south, but here, last month, some 400m of dunes disappeared into the sea, leaving a fast-eroding island where the tip of the spit had been.

The loss of this protective arm will leave Castlemaine Harbour and its internal promontories much more open to the ocean’s thrust. Rock defences at the gap, as volunteered by some locals, could end up making things worse. As sea level rises, and storms surge in, only coastal cities will warrant costly rearguard defences.

Given such subsuming trends it can seem surreal to worry too much about the minor wildlife of the coast, especially if it has already survived some of the planet’s most drastic upheavals. But either we’re caring for Ireland’s rare species or we’re not. The little natterjack toad is one of them. And it happens to live in just a dozen locations, on the coasts of Tralee and Castlemaine bays, where the rise in the ocean will add new problems. There’s a slow-motion race between losing their old breeding grounds and taking refuge in new ones, now dug and maintained by Kerry farmers.

The natterjack is a scampering, largely nocturnal, creature with a yellow stripe down its back. It is Ireland’s only toad. It was first found around sandy Castlemaine Harbour in 1805 and was long supposed to have arrived by accident, dumped out in sand ballast by boats trading with Spain.

Today’s DNA research, however, suggests the toads must have sat out the last Ice Age, when sea levels fell so drastically, in refuges closer to Ireland.

In modern times, to quote Dr John Kelly Korky, an American herpetologist “hooked” on Ireland’s toads: “Drainage projects, marine incursions, aquatic insect predation, fungal chytridiomycosis, precipitation fluctuations, eutrophication, acid rain, increased ultraviolet exposure, inbreeding, and synergistic effects of all factors have resulted in local extinctions.” The Rossbeigh erosion has sharpened his fear that climate change will threaten even sites that today seem secure.

Since the 1980s, the UK’s leading herpetologist, Dr Trevor Beebee of the University of Sussex, has been actively studying our surviving natterjacks, and helping to plan their restoration. Early on, the concern was about golf course development in Kerry’s dune systems. It was believed that the toads, used to breeding there in shallow, temporary, pools that dried out in summer, could not flourish in deeper, permanent ones, where their tadpoles would be eaten by great diving beetles and dragonfly larvae.

Today it seems that Ireland’s natterjacks have evolved markedly different habits from those in the UK, where they have to compete for their niches with abundant common toads. In fact, they are breeding at the edges of large, permanent, coastal lakes, and even in artificial golf links ponds, such as those at Castlegregory Golf Club.

Advised by Dr Beebee, the National Parks and Wildlife Service is now building up a network of ponds around Castlemaine Harbour, and near Fermoyle on Tralee Bay, to reclaim the natterjack distribution mapped from historic records. The toads are quick to spread from existing colonies, mostly within one kilometre of the sea, and the new ponds are shaped to suit them, shallow saucers scraped no more than one metre deep and 15m across.

Last year, the first in the project, 25 farmers dug two ponds each; another 15 farmers will join in the National Parks and Wildlife Service scheme this spring. An annual €500 per pond for five years includes keeping them clear of reeds by hand, controlling grazing around them to keep the grass short, and care of any nearby drystone walls in which the natterjacks like to hibernate. April should begin to show how well the scheme is working, as the calls of mating toads make a rolling, rattling chorus in the evening air.

EYE ON NATURE

There are a couple of peregrine falcons nesting in St Augustine’s on Thomas Street in Dublin city centre. A pair nested in the same spot seven or eight years ago. I saw one harassing a heron until it left the area.

Paddy Moloney, Church Street, Dublin 7

I watch three or four wrens fit into a house martin’s nest to survive the cold nights. Like treecreepers, they wriggle upwards, towards and into the nest, their tails pointing downwards.

Fons Jaspers, Portlaw, Co Waterford

On January 16th, on Portmarnock dunes, I saw two separate pairs of stonechats in mating display – the males flying vertically two to three metres, and fluffing on landing, while closely observed by the females.

Liam Manning, Portmarnock, Co Dublin

Two daffodils in bloom on December 31st. Formerly we hoped to get five or six for St Patrick’s Day.

Brigid Flanagan, Dundalk, Co Louth

Prior to the recent cold spell we had eight or nine blue tits. Now there are only two. Did they die of cold? I put out food regularly. The coal tits survived.

Mo Moloney, Virginia, Co Cavan

Nine out ten blue tits don’t survive their first year, cold nights in winter being one of the reasons.

Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo. E-mail: viney@anu.ie. Include a postal address.