Darjeeling is a part of the Eastern Himalayan zoo-geographic zone. Flora around Darjeeling comprises sal, oak, semi-evergreen, temperate and alpine forests. Dense evergreen forests of sal and oak lie around the town, where a wide variety of rare orchids are found. The Lloyd's Botanical Garden preserves common and rare species of plants, while the Padmaja Naidu Himalayan Zoological Park specialises in conserving and breeding endangered Himalayan species. Wildlife in the district is protected by the wildlife wing of the West Bengal Forest Department. The fauna found in Darjeeling includes several species of ducks, teals, plovers and gulls that pass Darjeeling while migrating to and from Tibet.