Steep Holm is protected as a nature reserve and Site of Special Scientific Interest (SSSI), notification having taken place in 1952. There is a large bird population, particularly European herring gulls "(Larus argentatus)" and lesser black-backed gulls "(Larus fuscus)". There has also been a small population of muntjac deer. The plateau at the top of the island has a layer of soil between and deep. It has a red colour from veins of iron in the rock and has arrived as sand particles less than in diameter. The island is the only site in the UK on which wild peonies "(Paeonia mascula)" grow, although these have been damaged by the fungus botrytis. The wild peony was introduced to the island of Steep Holm, possibly by monks, or brought from the Mediterranean by the Romans. Alexanders ("Smyrnium olusatrum") is also common along with golden samphire, buck's-horn plantain ("Plantago coronopus") and wild leeks ("Allium ampeloprasum"). The only reptiles on the island are slowworms ("Anguis fragilis").