Why do some tropical flowers open at night for bats?

Tropical plants that rely on bats for pollination—known as chiropterophilous or "bat-loving" plants—have evolved specific traits to attract these nocturnal mammals. Because bats are active at night, these flowers typically open after sunset to coincide with the time bats leave their roosts to feed.1

To ensure they are visible in the dark, these plants produce large, white flowers that are easily spotted by bats. They also emit musky or fermented odors to guide the animals. Furthermore, the flowers are often shaped like vases to accommodate a bat's face, or they feature brushy structures that coat the bat's whiskers with pollen.1

Beyond physical attraction, these plants provide essential nutrients. The pollen is rich in protein and contains amino acids like tyrosine and proline, which are vital for the bats' health, supporting wing membrane development and milk production. This mutualistic relationship is so refined that some plants bloom in sequence along "nectar corridors" to match the migratory paths of the bats.1