Of the many bird species found in the Mendips, the peregrine falcon (Falco peregrinus), which has gradually recolonised the area since the 1980s, is particularly significant. It breeds on sea and inland cliffs and on the faces of active and disused quarries. The upland heaths of the west Mendips have recently increased in ornithological importance due to colonisation by the Dartford warbler (Sylvia undata), which can be found at Black Down and Crook Peak. In Britain, this species is usually associated with lowland heath. The woodlands at Stock Hill are a breeding site for nightjars (Caprimulgus europaeus) and long-eared owls (Asio otus). The Waldegrave Pool, part of Priddy Mineries, is an important site for dragonflies, including downy emerald (Cordulia aenea) and four-spotted chaser (Libellula quadrimaculata). Waldegrave Pool is the only Mendip breeding site for downy emerald dragonflies. In 2007 the first confirmed sighting of a red kite (Milvus milvus) on the Mendips was made at Charterhouse.