Birr Castle Demesne is a very special place for biodiversity, it is its own little world of protected habitats, ecosystems, flora and fauna. The Demesne covers a large area of over 50 hectares, walled in on most sides and well monitored and protected from invasive species.
There are two rivers which flow from the Slieve Bloom hills to the south and into the Demesne. These two rivers first meet within the Demesne at the River Walk. The occasional shy otter can be seen in the larger river, the Little Brosna – sometimes their ‘slides’, where they slip into the river, are obvious to the trained eye. Kingfishers nest in the holes in the bank – again, they are shy but you may be lucky to see a flash of blue speed across the river. The chocolate brown birds with white bibs, Dippers, can be seen bobbing at the river’s edge seeking out food beneath the water. The red squirrel is our great success story as they are now back in good numbers and can often be seen throughout the Demesne.
Both of these rivers contain brown trout and the Camcor is known for its own special fish, the Croneen. This is a unique species, partly a lake trout, but pink like a salmon. It comes up the river in late August to spawn. If you get the timing right, you can see the fish jumping at the waterfall near the suspension bridge.
All areas are full of bird life, and it is a great delight for the bird watcher. You can often hear the croak of ravens and scream of swifts in the summer echo throughout the Demesne. The lake is full of mallard, moorhens and coot with little egrets an occasional visitor to the the area. Mute swans nest here as do grey herons. Birr Castle Demesne boasts the largest heronry in Ireland with grey herons having been known to nest here for at least 300 years. The nests and young on the island can clearly be seen by the visitor from the lake walk.
We also try to keep some of our areas wild for the native plants to flourish. The area we call, the Wilderness, in lower Cuil na hInch is seldom penetrated and left wild for trees to fall and grow as it does in nature. The park in front of the castle too, is a wonderful wildflower meadow in May. The area has never been ploughed and you may find at least 100 species of flowers and grasses there. Later in the year you may find orchids in many places, our rarest one is the Green Flowered Helleborine which has been found in our wooded area.