Hampstead Heath is an important refuge for wildlife, home to about 180 bird species, 23 species of butterflies, including grass snakes, foxes, rabbits, slowworms, squirrels and frogs. Common kingfishers, jackdaws, pipistrelles and Daubenton's bats are seen over the ponds. Some introduced species have also thrived at the site, for example muntjac deer, terrapins and ring-necked parakeets. The Heath is a Site of Metropolitan Importance for Nature Conservation, and part of Kenwood is a Site of Special Scientific Interest.