It has one of the highest rates of biodiversity per unit area - 1736 species per 100 square kilometers. There are about 1100 species of terrestrial vertebrates, including more than 100 species of mammals and 170 species of birds that are believed to be found nowhere else.
There are about 13.500 plant species, 3200 of which are found exclusively in the Philippines. Rare species of orchids and rafflesia (Rafflesia arnoldi) are found in the rainforest. The tropical climate is conducive to the growth of flowering plants, including the ylang-ylang or Sampaguita (Jasminum sambac) - considered one of the most beautiful flowers in Asia and the Pacific, and is also the national flower of the Philippines.