Being home to more than 840 flowering plants and 500 species of animals, it contains 40% of Singapore's flora and fauna. A common tree there is the Seraya ("Shorea curtisii"), which dominates the forest canopy of BTNR. Rare plants such as the Mock Durian ("Neesia synandra") can also be found there. The Mock Durian, as its name mentions, produces fruit that look like durians, but they are inedible. Forest Praying Mantis and the Singapore Freshwater Crab are some of the rare animals found there. Pangolins, Horsfield's Flying Squirrel, Plaintain Squirrel, Malayan Colugo, also known as the Malayan Flying Lemur, as well as the Giant Forest Ant all live at BTNR. There are also many Long-tailed Macaques, which is the most common monkey in Singapore. Other than that, BTNR also has rich bird and insect life. Cicadas can be heard everywhere. Many species of birds and butterflies can also be spotted there. However, the birds, like the cicada, are more often heard than seen. Some of the birds spotted there are the Greater Racket-tailed Drongo, Asian Fairy Bluebird, Red-crowned Barbet and Emerald Dove. In March 2011, a Dot-Dash Sergeant ("Athyma kanwa"), which is a rare butterfly in Singapore, was spotted along the Red Trail. Some of the other butterflies spotted there include the Common Faun ("Faunis canens"), Common Caerulean ("Jamides celeno") etc. One species of monkey, the crab-eating macaque is common in the park.