The Mullaghareirk Mountains form part of the Stack's to Mullaghareirk Mountains, West Limerick Hills and Mount Eagle Special Protection Area which, although large areas are under commercial conifer forestry, protects blanket bog, wet heath and dry heath. The area has been designated as a Special Protection Area under the European Union's Birds Directive and was so designated to protect the hen harrier. A survey in 2005 found 45 breeding pairs, representing more than 20% of the total for the whole island of Ireland. Other rare birds found here include breeding short-eared owl, merlin and red grouse, a species which is now listed as endangered in Ireland. The SPA was designated in 2007 and has a total area of .