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Ivan Buddenhagen argues that without bats to pollinate wild bananas and disperse their seeds, these ancient plants would eventually disappear from tropical forests.
June 2009
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I. Buddenhagen
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Wild bananas share with bats a long history that started some 50 million years ago. For practical purposes, we will divide wild bananas into two types: the ‘ornamental’ bananas with upright inflorescences, and the ones with horizontal or pendulous inflorescences, which gave rise to our edible bananas (with the exception of the Fe’i bananas, a small group of bananas with an upright inflorescence that was domesticated in the Pacific region).
Birds, mostly sunbirds of the family Nectariniidae, pollinate the upright ornamental bananas, whereas fruit bats, including flying foxes, of the family Pteropodidae not only pollinate non-ornamental wild bananas, but also disseminate their seeds.
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Merlin Tuttle
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A greater short-nosed fruit bat, Cynopterus sphinx, on a wild M. acuminata in Thailand.
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All bananas, whether a seedling germinating from a seed dropped by a bat, or a sucker taken from a mother plant, develop the same way. The growing point remains near ground level as each new leaf shoots up through the previous leaves. The leaf lamina unfolds after emergence at the top of the pseudostem. After all the leaves have been produced, the growing point initiates the inflorescence, the true stem, which is then thrust upward and emerges at the top. The female flowers, whose ovaries become the fruit, develop first, followed by the male flowers. Each whorl, or double row, of flowers is hidden by a large bract which opens to reveal them. A new bract opens every day or so, exposing flowers carrying abundant pollen.
The male and female flowers produce an abundance of sweet nectar whereas the bud exudes a strong odour, both of which are attractive to fruit bats. Commercial bananas do not need to be pollinated, but because their flowers still produce abundant nectar, they are visited by bats wherever they are grown. In Asia, where bananas are native, and in Africa, where they are introduced, one can see evidence of bats visiting flowers from the scratches they make with their claws as they cling to the bud and lap nectar from the flowers.
Bananas and bats seem to be made for each other. The male and female flowers are not particularly colourful, which is not a problem for the nocturnal bats, but the abundant nectar in the flowers is easily accessible. The inflorescence is also conveniently sturdy, making it possible for bats to use it as a perch. In addition to being a valuable pollinator of bananas, bats are also one of the major dispersers of their seeds.
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I. Buddenhagen
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A mother and baby “flying fox” before being made into soup, Sumatra.
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Wild banana fruit are full of very hard black seeds the size of small peas and have very little pulp. They are unpalatable to humans, but bats, monkeys and other animals eat the fruit and disperse the seeds. After the fruit have matured and the mother plant has died, one of the suckers at the base of the plant will take over. But clumps of vegetatively reproduced bananas are short-lived. They are overtaken by jungle and generally die within five years. To thrive, populations must be pollinated every year and produce seed that must be disseminated away from the mother plant. Over vast areas of banana’s range, however, the forest is being cut down and replaced by crops. This is also destroying the bat’s habitat. People who lived in Djakarta, Indonesia, in the 1930s recall the magic of watching the skies darken at night as enormous flights of flying foxes blocked out the setting sun. Such flights are long gone. The colony of flying foxes that used to inhabit the great botanical garden at Bogor, some 80 kilometres away, is also gone. In many places people capture, sell and eat bats, especially the large flying foxes. Once, in Sumatra we bought all the bats on sale in a market and released them in the mountains, a token gesture compared to the vast numbers that are caught and eaten.
It is urgent that the remaining wild bananas are collected before any more go extinct. But it is also very important that the depredation on the various species of bats that pollinate them and disperse their seeds be curbed, not only for the sake of bananas. Nearly 200 species of bats are known to pollinate more than 250 species of trees. The wholesale loss of bats would have devastating effects on tropical forests.
For more information, contact Ivan W. Buddenhagen at
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For more information on bats, visit the Bat Conservation International website. Their publication, BATS magazine has an article on bats and wild bananas in its Winter 2008 issue.
Articles on pollination of wild bananas and the importance of flying foxes:
Nazar Nur. 1976. Studies on Pollination in Musaceae. Ann. Bot. 40: 167-177.
Marty S. Fujita and Merlin D. Tuttle. 1991. Flying Foxes (Chiroptera: Pteropodidae): Threatened Animals of Key Ecological and Economic Importance. Conservation Biology 5(4): 455-463.
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