Posted 02/09/2020

Pollardstown Fen

Pollardstown Fen is the largest remaining calcareous spring-fed fen in Ireland. 
The area of the fen is 220 hectares and a large portion of it is state owned.

It is recognised as an internationally important fen ecosystem with unique and endangered plant communities. It contains a number of rare vegetation types and invertebrates
Undisturbed fens are rare in Ireland. 

Curragh Aquifier

A fen is an area of alkaline peatland that obtains its nutrients from calcium rich spring water. The springs are found mainly at the edge of the fen. Most fens develop further into raised bogs. Raised bogs contain acid peat and their only source of nutrients is rainfall.  

The fen was declared a National Nature Reserve in 1986.

Pollardstown Fen is maintained by groundwater from the Curragh Aquifier, a natural underground store of water. The Fen is one of the main places where the aquifier's water table meets  ground level. 

A boardwalk route has been installed by the National Parks and Wildlife Service to allow visitors to experience the fen up close.

    Fen Vegetation

    Pollardstown Fen is best known internationally for its extensive areas of fen vegetation dominated by Black Bog Rush and Saw Sedge, a vegetation type almost unique to Ireland. 
    Pollardstown also supports a number of rare and threatened plant species including Orchids and Insect-eating plants

    The Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species.
    Other typical fen plants include Tufted SedgeSlender Sedge, and Blunt Flowered Rush

    Orchidaceae is a diverse and widespread family of flowering plants, with blooms that are often colourful and often fragrant, commonly known as the orchid family.
    Look out for the Fly Orchid in the Fen
    Other vegetation in the Fen includes Western BladderwortSphagnum Moss and Broad-leaved Bog Cotton

    Fen Birds

    The summer in Pollardstown Fen is a good time to visit and see lots of birds on the lake, with Sand Martins swooping low over the open water hunting for insects. The fens, reeds and grasslands are also home to Skylarks

    It is sometimes easier to hear some bird speicies rather than see them, as they call and sing loudly, defending their territories.

    In winter these birds are joined by migrating wildfowl. 

    Birds in the Fen include Mute SwansHerons and Little Grebes
    In winter these birds are joined by migrating wildfowl. 

    You might also see Coots, which have predominantly black plumage, Moorhens / Marsh Hens, which are members of the Rail family.

    You will also find Reed BuntingsSkylarksWater RailsSnipe, and Sedge Warblers
    And there are Pintail Ducks and Tufted Ducks

    Mammals, Amphibians, Invertebrates, Fish


    Fen Mammals
    A number of mammals also live on the fen along with common amphibians. 
    This includes the OtterHare, and the Pygmy Shrew.
    It was, until very recently, the only shrew native to Ireland and is Ireland's smallest mammal. 
    It weighs at most about 6g

    Fen Amphibians
    Amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. 

    Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin.

    On the Fen you will find the Common Frog and Smooth Newt.

    Fen Invertebrates
    The fen also supports many species of invertebrates
    Invertebrates are animals that neither possess nor develop a vertebrae, derived from the notochord
    This includes insects, crabs, lobsters and their kin, snails, clams, octopuses and their kin, starfish, sea-urchins and their kin, and worms.
    The majority of animal species are invertebrates. One estimate puts the figure at 97%.

    The Fen is home to Dragonflies and Damselflies.

    Adult Dragonflies are characterized by large multifaceted eyes, two pairs of strong transparent wings, sometimes with coloured patches, and an elongated body

    Damselflies are similar to dragonflies but are smaller, have slimmer bodies, and most species fold the wings along the body when at rest.

    Other Invertebrates to be found in the Fen are Butterflies such as The Orange TipTortoiseshell, and the Common Blue.

    Fen Fish
    In the water you will find the Brook Lamprey, a fish species commonly mistaken for a small eel, and the lobster-like crustacean, the White-Clawed Crayfish.

      Location and Safety



      Pollardstown Fen National Nature Reserve is located 3km west of Newbridge in Co. Kildare. A bird hide located in the southern section of the nature reserve is open to the public. 

      Safety on the Fen

      • Watch where you are walking
      • Stop walking while watching birds
      • Children should be strictly supervised.
      • Enter the fen only by the main entrance
      • Stick to the walking track.
      • Do not pick plants and do not disturb animals.