The Bats of Cascade Wood
Cascade Wood lies in the West Cork Gaeltacht within the village of Ballyvourney, between the towns of Macroom and Killarney, Co. Kerry. It is a small woodland of approximately 40 acres and was threatened by the proposed bypass of the village by the N22 road re-alignment. The carriageway was to cut this broadleaved woodland in half. The wood is about 150 years old – the result of plantation by a local landlord - and includes mature oak and beech as well as Scot’s pine. The understorey is heavily infested in places by rhododendron. A unique feature of the woodland is a deep gorge cut by the Bohil River through sandstone. This has sheer cliffs of 25 metres or more on both sides and the river enters the gorge in a torrent. Several rare species of plants and fungi have been identified on site and the micro-climate within the gorge with its high humidity may lead to further discoveries.
The local residents’ action committee, who were campaigning to have the road re-routed to the north, concentrated on the rarer species which inhabit the wood including red squirrel and otter and the unique Kerry slug, an Annex II species under the European Habitats Directive, which is only found in the south west of the country.
This slug was first discovered in Co. Kerry in 1842 and was subsequently found in the north western coastal region of Spain and Portugal. Also, known as the Irish spotted slug, the species can reach a length of 9cm and is unusual in that it rolls into a ball when disturbed instead of making itself smaller like other slugs. It can live up to seven years. The slug is a survivor from pre-history when a land bridge connected the south west of Ireland with the north western Iberian Peninsula.
Cork County Bat Group was asked to provide a bat survey of the woodland and this was undertaken over several periods from 2005 to 2007. In total, seven and, possibly, eight bat species were recorded by detector within the woodland so the species diversity was very impressive. The surprise was finding lesser horseshoe bat – another Annex II species - on site as this species was unknown in the local area until then.
Once the roost was identified – a disused two-storey farmhouse 400 metres from the woodland, a licence was obtained from the National Parks and Wildlife Service to undertake a radio telemetry study on one of the animals from the small colony in the building. A radio transmitter was attached to one bat, a male, and this was tracked by receiver over the next nine nights to discern its movements in the landscape around the site.
The bat was found to use the hedgerows leading from the colony’s roosting site to reach feeding areas within a one kilometre radius. Its nightly foraging flights included Cascade Wood. Further investigations are underway to try and gain access to a very large farmyard complex near the woodland as it is assumed to be the main roosting site for this species in the area, unfortunately, the owners are not co-operative at present.
The report on the initial bat assessments of the wood was forwarded to the NPWS in March 2007 with the recommendation that the road be re-routed to avoid the wood completely due to its importance to bats.
In September, Environment Minister John Gormley issued a press release designating the woodland a Special Area of Conservation specifically because of the presence of the Kerry slug and diverse bat species. He informed the National Roads Authority that they would have to re-route the new road to the north of the site.
The Cork County Bat Group warmly welcomes this unprecedented act by the Minister. It is a decision that has received widespread media coverage as it emphasises the difference a knowledgeable Minister for the Environment can make.
Cascade Wood will now be managed and the rhododendron infestation will be cleared so that the ground flora can recover. Also, further studies and surveys are needed on site to investigate claims of the presence of the extremely rare Killarney fern.