How hot dogs and peanut butter help to monitor mammals

ANOTHER LIFESINCE OUR OLD DOG, Meg, crept off into the bushes to breathe her last in private, the acre has been running a bit wild. Hares are commuting past the woodshed, and blackbirds march around half-moulted, having quite ceased to live on their nerves. The nearest farm cat, unmissably big and white, has returned to stalk the baby wrens. (Meg used to give her a hard time.)

And now a rabbit is laying siege to the polytunnel. Roaming up from the dunes at the bottom of the hill, it found the tunnel open at both ends, to stir the air in this miasmic summer. It munched on half a dozen lettuces and fronds of florence fennel and then began to burrow into the raised bed beneath the towering tomatoes. Shocked to discover the sudden, big, round hole, I blocked it with a rabbit-sized rock.

Next morning, a second excavation had scattered the soil beside it, and I undertook defences: wire netting at one end, an old wooden door, on its side, at the other. Returning later to inspect, I found I had trapped the rabbit inside the tunnel. Leaping from the hole it had begun beneath the courgettes, it took off on a terrified circuit, hurtling perilously past the peppers and taking the basil at a leap. I prayed it would find the gap I had come in by, and it did.

As I write, the defences are holding, and if, indeed, this was a doe rabbit, pregnant and preparing to multiply, she can dig her hole in the ditch, preferably close to a stoat.

Should I tell mammals.biodiversityireland.ieabout my rabbit? I hardly think so. While they've mapped the raccoon in west Cork, the red-necked wallaby on Lambay Ireland and the feral ferrets in Ulster and Munster, there are far more pressing whereabouts to be charted for its atlas of mammals in Ireland. By 2015, nonetheless, the rabbit will need to take its pestiferous place in baseline maps of the island's everyday mammals.

The first two years of the atlas project have been a great success, thousands of historic records digitised and loaded to the database at the National Biological Records Centre, in Waterford, and hundreds of new ones added every month by the project's voluntary recorders. At maps.biodiversityireland.ie, mammals are a small but burgeoning part of a very high-tech, many-layered but just-about- navigable database. (The centre does, after all, manage more than two million records of the island's myriad species.) Tempted, in passing, to browse the maps and dates of 11 visits from walruses to the west coast, one presses on to more likely current creatures: hedgehogs, pine martens, stoats, otters and others great and small.

Quickly evident is the number of new sightings from Mammals in a Sustainable Environment (Mise), the EU-backed regional project meant to get local communities in Ireland and Wales involved in mammal surveys. It is led from Waterford Institute of Technology, on whose campus the records centre is based; you can browse its activities at miseproject.ie.

On August 18th, for example, a Mise day in two Waterford woodlands will guide teams of volunteers (ask Denise O’Meara at domeara@wit.ie) in looking for signs of pine martens, foxes, deer and squirrels. Reports of previous such surveys, from the sand dunes of Tramore to the woods of Tipperary, show how reassuringly low-tech the means of detecting a mammal can be.

It’s true that pine-marten scats are now put through DNA analysis at WIT to identify individual animals, but otter spraint still offers that conclusive whiff of anal musk (quite pleasant), and owl pellets are still picked apart for indicative little skulls. Newer detective techniques are still simple, but also ingenious and cheap. Plastic tubes baited with hot dogs and peanut butter have induced hedgehogs to walk across pads soaked in poster paint and leave their footprints on white paper. Other baited tubes have sticky pads that take samples of hair from pine martens or squirrels.

Could stoats, too, be tempted through smaller tubes, leaving some hairs behind? This was tested in Co Galway, using the experience of the Vincent Wildlife Trust, the UK conservation charity, already a guardian of western Ireland’s rare lesser horsehoe bats. In 2010 Dr Kate McAney, the trust’s Irish operative, with funding from the Heritage Council, found 50 volunteers to place 600 small plastic tubes (5cm across, 20cm long), each stuffed with rabbit meat and strung with glue-smeared rubber bands, pegging them down beside selected hedgerows and stone walls. Left for a week, they yielded 338 wisps of hair, from which DNA sequencing sorted 36 stoats (rather than rats or shrews). So that works.

Nobody knows how many stoats there are in Ireland – plenty, I feel sure. The last one we saw was on the kitchen window sill (see my drawing), nibbling at the winter fat we’d put out for the birds. I hope it’s still around and likes its rabbit with the fur on.

Eye on nature

A fish-like creature is lurking in my pond. It is about 35mm in diameter and 80mm long. We did have sticklebacks, but they are all gone. We still have frogs and tadpoles.

Peter White, Rathmines, Dublin

From the photograph you enclosed, it was a neotenous tadpole, one that kept growing without developing into a frog. It could live for a year or more and (exceptionally) grow to 120mm long.

I enclose a photograph of a very small beetle that I found on our raspberries. It is barely 5mm in length. The beetle is round, yellow in colour and covered with dark spots.

Patrick Lynch, Collon, Co Meath

It is a 22-spot ladybird, Thea 22-punctata, that lives mainly on mildews.

On July 20th I had the good fortune to see a corncrake in flight twice on the one day within 200 yards of Roscommon’s main street. My work colleague had heard it call the previous evening.

Sean Kelly, Ballinasloe, Co Galway

This has been the worst year ever for slugs and snails in my 40 years’ gardening experience in our suburban garden. They have attacked plants that they never bothered with heretofore and in great variety and numbers.

Joe Scully, Tallaght, Dublin

Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo, viney@anu.ie. Please include a postal address