The diversity of Carlow’s habitats and species reflect the varied geology, landforms (mountains to river valleys), soils and land uses across the county, with limestone bedrock towards the west, granite towards the east, shale and sandstone around Old Leighlin, and pockets of schist and sandstone between Clonegal and Myshall.
In the north-east of the county, between Rathvilly, Hacketstown and Tullow, the tributaries of the River Slaney catchment are important spawning and nursery habitats for salmon, while their riparian zones support otters and kingfishers. In between these, the landscape is dotted by gorse-covered hilltops and bluebell-filled oak woodlands, with pockets of semi-natural wet grasslands adding further colour.
Moving south, from Myshall down to Drummond, the landscape is dominated by the Blackstairs mountain range, with large expanses of blanket bog, dry heath and wet heath, along with pockets of rock and scree, dry-humid acid grassland, fen, scrub and several different types of woodland, including bog and wet woodlands. The area is home to pine martens, hares, stoats, and red squirrel, along with kestrel, merlin, peregrine falcon, and of course, the red grouse.
Carlow’s western boundary, from St Mullins up to Muine Bheag, is dominated by the River Barrow catchment, with pockets of alluvial (riparian) woodlands and tall herb communities supporting important food webs, with midges and mosquitoes feeding damselflies and dragonflies, which in turn are prey for bats and birds. Similar to the River Slaney, the tributaries of the Barrow are ecologically richer than the main channel as a consequence of navigational works.
The River Barrow floods at a number of locations each winter, including the stretch between Cloydagh and Powerstown. The flooded lands attract nationally important numbers of lapwing and large wintering flocks of golden plover, as well as smaller numbers of curlew green sandpipers. Further north-west, as the land rises back towards Bilboa, blanket bog, semi-natural grasslands and forestry abound, with buzzards scanning the area for something to catch, the rare and protected marsh fritillary butterfly fluttering between devil’s-bit scabious plants, and other rarities, such as the blue fleabane flower and orchids, popping up where old quarries have created niche habitats.
The River Burrin flows through the centre of the county, flanked by a patchwork of arable and pasture fields, some of which are wet or unimproved and species rich, with low hedgerows that provide important nesting habitat for a range of birds, shelter for hedgehogs and rabbits, and feeding corridors for bats, despite the tight management of many Carlow hedgerows restricting their ecological potential.
All across Carlow, there are hidden habitats in the corners of farmlands and parklands, including small ponds, marshes, wet grasslands, fens and bogs. Small groves of trees, some of them wet, are more visible on the landscape, as are individual mature trees. All of these habitats combine to give Carlow a rich wildlife assemblage that the people of Carlow can be proud of, including ivy broomrape found near Borris, bee orchids found near Muine Bheag, and six rare lichens found in Carlow’s ancient woodlands (Clongrennan Wood, Toberbride Wood, and Drummond Wood).
In addition to these, there are many historic parks and gardens throughout Carlow, which support unique collections of biodiversity. The walled gardens at Ducketts Grove, surrounded by flat and intensively managed farmland, are an oasis for foraging butterflies, moths, bumblebees, and many other insects and birds, while the veteran woodland outside the gardens supports whole ecosystems, with fungi, beetles and other invertebrates finding all they need in the decaying wood.
The mature mixed-broadleaved woodlands at Oak Park Forest Park are home to an extensive collection of ferns, mosses and woodland flora, while the lakes and islands provide food and shelter for swans, ducks and other water birds. Further south-east, the sensitive balance of formal and informal planting at Altamont Gardens, with its arboretum, lake, and old oak and hazel woodlands, is yet another haven for wildlife.
Old buildings, bridges and other structures, of which there are many throughout Carlow, are also important for biodiversity. Modern building designs have reduced the nesting sites available for birds like the barn owl and swift. Bats, such as pipistrelles and Leisler’s bat, often roost in attic spaces, whereas Daubenton’s bats roost in the crevices under bridges (they feed along the surface of rivers), along with birds such as dippers and grey wagtails.
Historic graveyards can be particularly important biodiversity refuges, with their grassland areas, which are likely to have never been fertilised, harbouring a diverse seed bank. Their stone walls, church ruins and gravestones can also support rare plants, and in particular, ferns, mosses and lichens.
For further information, please contact the Carlow Biodiversity Officer at environment@carlowcoco.ie