much of anglesey is used for relatively intensive cattle and sheep farming. however, there are several important wetland sites that have protected status. in addition, the several lakes all have significant ecological interest, including their support for a wide range of aquatic and semi-aquatic bird species. in the west, the malltraeth marshes are believed to support an occasional visiting bittern, and the nearby estuary of the afon cefni supports a bird population made internationally famous by the paintings of charles tunnicliffe, who lived for many years and died at malltraeth on the cefni estuary. the raf airstrip at mona is a nesting site for skylarks. the sheer cliff faces at south stack near holyhead provide nesting sites for huge numbers of auks, including puffins, razorbills and guillemots, together with choughs and peregrine falcons. anglesey is home to several species of tern, including the roseate tern. three sites on anglesey are important for breeding terns – see anglesey tern colonies.