The Philippine Tarsier by Eric F. Muaña.
Tarsiers are little-known nocturnal primates, about the size of a tennis ball. Once more widespread, tarsiers are now limited to the Southeast Asian islands of the Philippines, Malaysia, Brunei, and Indonesia. There are 10 tarsier species and four subspecies, belonging to a sister group of monkeys and apes. Extinction threatens all tarsier species, to some degree.