Overcome by the pong of a pine-marten den? Count yourself lucky

Another Life: Michael Viney on the slow return of one of Ireland’s rarest mammals

A friend who lives on a windy hilltop, in a house nestled in trees, called to tell of a strange smell in her woodshed. There was something, perhaps, going on in one corner, behind a pile of tools. She had glimpsed a furry tail.

This is the season when furry animals have babies – and a leafy hilltop adjoining conifer forestry made the pine marten, notorious for siting its nursery in attics and sheds, the likely candidate.

A listen at the door was rewarded by sounds of mewing from the corner, as of kittens. The scatter of droppings on the floor matched that of Martes martes, or the Irish cat crainn. We retreated, happy that Ireland's rarest mammal, long in slow revival after centuries of decline, was staking out a new domain above the western shore.

As a connoisseur of the musky, unmistakable aroma of otter spraint I was quite looking forward to a new olfactory experience

What might have clinched the matter was the distinctive smell of the scat, so often described as like that of Parma violets, even by people without great experience either of the flower or of the scented English sweet of the same name.


As a connoisseur of the musky, unmistakable aroma of otter spraint – sampled from the greenest, best-fertilised tufts of grass on stream banks – I was quite looking forward to a new olfactory experience. The overwhelming fragrance of the shed, however, was that of Jeyes Fluid, my friend being one of many householders repelled by the alternative odour, redolent of violets or not.

I did not have to go far online, indeed, to find a blog complaining of "having to move downstairs" to escape the pong of a pine-marten den in a roof space. So mixed, indeed, are responses to these intrusions that the Vincent Wildlife Trust has put a special leaflet online: The Pine Marten in Ireland: A Guide for Householders. It could be prudent reading for people now returning to their rural holiday houses.

The shortage of natural den sites in Ireland (notably in trees old enough to have big holes) has made houses and sheds attractive to female martens seeking seasonal warmth and safety. They are a long-protected species, and will abandon their kits if disturbed.

The two or three young themselves will want to play by night – martens are largely nocturnal. So their noisy skittering on bedroom ceilings can be unwelcome. But from March to July, action to evict a family could bring prosecution under the Wildlife Act.

The Vincent trust readily admits that martens “do not make good house guests” and urges proofing the house against invasion. But the animals are superlative climbers and can squeeze through gaps as big as their head (5cm for females).

A second leaflet, supported by the National Parks and Wildlife Service, addresses more of the martens' misbehaviours. How to eExclude Pine Martens from Game and Poultry Pens describes in detail electric fencing to protect the gun clubs' pheasant chicks and ways of making a henhouse martenproof.

The predatory diet of this much-abused native mammal includes neither newborn lambs nor babies left out in their prams

All this may stir questions about what pine martens are “good for” and reinforce the wilder concerns for newborn lambs and babies left out in their prams. The predatory diet of this much-abused native mammal includes neither (except, at times, bits of dead lamb) and embraces even frogs, snails, beetles and blackberries. More helpfully to humans, it is a control on rodent populations and its hunting of rats and mice, bank vole and white-toothed shrew extends even to grey squirrels.

This, as recent Irish research has shown, can help restore numbers of the native red squirrel. The red is lighter and more agile, and can retreat to the far ends of branches, while the bigger grey also spends more time on the ground and is easier to catch.

This study, carried out in Co Wicklow woods by Dr Emma Sheehy of the University of Aberdeen, found the fur of grey squirrels, but not of reds, in marten scats. It has had wide attention in Britain, where restoration of the marten in Scotland, Wales and northern England and conservation of red squirrels are priorities.

In Ireland, meanwhile, the research has been intensive, including genetic study of DNA from marten hairs left in sticky tubes baited with raw chicken. This helped the large-scale assessment of the marten population published last year by the National Parks and Wildlife Service.

Led by Dr Declan O’Mahony of Northern Ireland’s Agri-Food and Biosciences Institute, the report identified 134 individual martens at sites spread across the island, with an average low density of about one animal per square kilometre of forest. Combining this with other data, the total population in Ireland was estimated at 3,043. This confirmed the pine marten as a settled and stable resident, but still one of the rarest mammals in Ireland.