Waterford Wildlife - 'Islandisation'

Wednesday, 9th April 2008

Motorways are said to be integral to our economic growth. Insofar as they enable salesmen and truckers to deliver goods quickly between cities and ports, they probably are. Even leisure-users such as birders chasing the latest rarity in the farthest reaches of the country are indebted to those who secured EU funding to make the road-time between places half what they used to be. But the reduction in journey times are being made at the expense of the environment.

Building four or six-carriage motorways may work wonders for the economy, but the costs to wildlife are enormous. These are obvious: road-kills, Rooks, Wood Pigeons, Badgers, Foxes, Stoats and Rabbits are mown down in their thousands simply because they cannot cross wide roads safely with traffic speeding in two directions. This is confounded by the routing of motorways. They tend to be routed to minimise journey times for maximum economic benefit. Avoiding sites of wildlife importance (or architectural) is seldom, if ever, a primary concern of road planners.

Every local authority has its county or city development plan and is committed to protecting sites designated for protection and conservation for wildlife, but preferred routes often pass near or even through protected areas. This is worrying but there is more.

It is clear that the construction or widening of major roads is creating barriers to normal wildlife movement and is creating 'islands' of land within Ireland and Waterford. Called 'Islandisation' by environmentalists, this is now considered to be one of the greatest threats to local biodiversity in the developed world. An exotic example is given in the BirdWatch Ireland magazine 'Wings'. A particular tropical bird feeds solely on soldier ants. When the ants march off to another patch of forest across a road or clearfell, the bird dare not follow as they are conditioned to remain under forest cover. They are then left with no food and they die. This bird is expected to become extinct as its forest habitat is carved up by roads and tree-felling.

The same is happening here but in a less spectacular way. Our main roads and motorways are carving the landscape into islands of land separating terrestrial wildlife from their brethren and so reducing the gene pool in each 'island' with inevitable local extinctions. Scientists describe this new phenomenon as 'stochastic extinction'. It is widespread here and is probably causing the demise of Waterford's population of Pine Martin that is now confined to a few particular woodland 'islands' with only very hazardous access to others of its own kind. All of the most recent reports of Pine Martins in Waterford were of road kills.