The serendipity of research with Google can tempt one into fanciful propositions: you never know what may turn up. Thus, pairing the keywords “beaver” and “Dodder” invoked the unlikely discovery of an alien mammal on Dublin’s favourite wild river.
What it revealed, at least to me, was the existence of Beaver Row, a terrace of 18 surviving 200-year-old cottages in fashionable Donnybrook and within a stone's throw of where salmon leap up a weir in the river Dodder.
For their history I am indebted to a 2012 thesis by Glenda Cimino for the NUI Maynooth Certificate in Local History. As the lucky owner of Number 9 in Beaver Row, Cimino withstood pressure from would-be developers and declares: "It is almost a miracle that the row has survived."
They worked with imported fur of the animal in a trade that was already threatening the beaver's extinction in Europe
What, then, of “beaver” in its name? Cimino traces it to the enterprise of the Wrights, three community-minded Wesleyan brothers who built the cottages in 1811 for workers in their hat factory, linked by a bridge across the Dodder.
They were felters, making the fashionable “beavers”– hard-wearing, waterproof, wide-brimmed top hats for men. They worked with imported fur of the animal in a trade that was already threatening the beaver’s extinction in Europe. The alternative source of supply was north America and the Hudson’s Bay Company.
The vogue for beaver hats lasted up to the mid-19th century, when silk became more competitive in price and produced a glossier hat.
Along with their fur, beavers were hunted for their meat and for castoreum, a glandular secretion valued as an early tranquilliser for anxiety. None of these, it seems, merited their transport to Ireland and, unlike the otter, beavers never set out across the North Channel.
Would introducing some now be a useful idea? The island next door had beavers galore in the Stone Age. Their reintroduction is now widespread as a way of holding back the floods of climate change, increasing biodiversity and cleaning up river water.
As large vegetarian rodents with strong front teeth for chewing wood and eating tough water plants, beavers are exceptional eco-engineers. Felling young birch and willow along riverbanks, the dams they construct and weave with branches create pools of calm water for fish, otters, frogs, dragonflies, water birds and bats.
The trees they fell are not killed but sprout again in a kind of coppicing. The beavers don’t live in the dam itself, but in a dome or lodge of twigs built out in the deep water of the pond.
Hunted to extinction in the 1600s, their restoration began in Scotland in 2009. This was quickly followed by licensing at locations across Britain, with support from the forestry commission and other government agencies. As Patrick Barkham noted in the Guardian, beavers have replaced croquet lawns as a proper accessory for country estates.
A conservation success, it brought its own problems. In southern Scotland, a surge in beaver populations has reached about 1,000 animals in 251 river territories. Unwelcomed by some farmers, 115 beavers have been shot (also under licence) while others have been trapped and relocated to rivers in England and Wales.
In the latest project, the rewilding group Citizen Zoo plans to release beavers into marshland in London's Tottenham area, better known for its football stadium.
Fogarty cites the many man-made introductions to Ireland, such as pheasants, sheep and Pacific oysters
Irish ecologists have been dismayed by the entry of "invasive aliens" to the island. The impact of the greater white-toothed shrew on native species prompted Prof Ian Montgomery of Queen's University to warn of an "invasional meltdown" if such arrivals multiplied.
The multiple benefits of beavers, however, are persuasive. In a recent blog for the Irish Wildlife Trust, campaign director Pádraic Fogarty made a telling case for reintroducing them and found he could not offer sound arguments against.
Fogarty cites the many man-made introductions to Ireland, such as pheasants, sheep and Pacific oysters, and suggests that it is “too late to be warning about the risks of playing god. What we do or don’t do at this point in time will mark the destiny of the natural world for good or ill. Not playing God is not an option.”
A good place to start with beavers, he suggests, might be the rehabilitated midland bogs, where their dams would speed up the rewetting and make them “climate action heroes”.
But wouldn’t the beavers need a few more trees? On Dublin’s river Dodder, on the other hand, leafy enough and prone to flash floods. There’s a thought . . .
