Durian has yet to take off as a major fruit in the West. This might be due to the smell, which as been described as “turpentine and onions, garnished with a gym sock“.
Despite this demand is booming for durian. And this means that management of durian orchards is becoming more pressured. Obviously there’s no fruit without pollination and durian has some unusual pollinators. Chiefly it seems to be pollinated by bats, along with spiderhunters (a bird) and giant honey bees. This is due to a rich nectar, which packs 869 calories per millilitre. To get a whole millilitre you’d need to visit just three flowers. That’s quite a food source and it’s not just attractive to cave bats and birds. It also attracts Pteropus hypomelanus, the flying fox, the biggest fruitbat in the world. What happens when a massive bat hits the durian trees? It’s been thought that it’s damage to the flowers, but a team of scientists have been investigating further.
Using camera traps, researchers collected video evidence showing the island flying fox (Pteropus hypomelanus) pollinating durian flowers, leading to the production of healthy durian fruit. Their study – Pollination by the locally endangered island flying fox (Pteropus hypomelanus) enhances fruit production of the economically important durian (Durio zibethinus) – has been published in the Journal of Ecology and Evolution.
This is critically important news for durian farmers as the island flying fox is already classified as ‘endangered’ on Malaysia’s National Red List.
Large fruit bats of the genus Pteropus are severely threatened by hunting and deforestation. They are often sold and eaten as exotic meat due to an unsubstantiated belief that consuming them can help cure asthma and other respiratory problems. They are also persecuted and killed as agricultural pests, as some people claim that the bats cause damage and economic loss by feeding on cultivated fruits.
Consequently, these factors have led to a severe decline in flying fox populations worldwide. This could be a problem for tropical plants in fragmented habitats, such as durian plantations isolated by deforestation.
Dr Ahimsa Campos-Arceiz, one of the coauthors of the study, said: “The durian is a fascinating plant that, with its flowers pollinated by bats and its seeds dispersed by large animals like elephants, beautifully exemplifies the importance of plant animal interactions. The durian fruit is particularly famous for its pungent smell and unique taste, adored by most people in Southeast Asia and so often misunderstood – abhorred? – by westerners. We hope this study brings attention to the urgency of conserving flying foxes in Southeast Asia.”
Yumoto, T. (2000). Bird-Pollination of Three Durio Species (Bombacaceae) in a Tropical Rainforest in Sarawak, Malaysia. American Journal of Botany, 87(8), 1181. https://doi.org/10.2307/2656655
Aziz, S. A., Clements, G. R., McConkey, K. R., Sritongchuay, T., Pathil, S., Abu Yazid, M. N. H., … Bumrungsri, S. (2017). Pollination by the locally endangered island flying fox (Pteropus hypomelanus) enhances fruit production of the economically important durian (Durio zibethinus). Ecology and Evolution. https://doi.org/10.1002/ece3.3213
Fleming, T. H., Geiselman, C., & Kress, W. J. (2009). The evolution of bat pollination: a phylogenetic perspective. Annals of Botany, 104(6), 1017–1043. https://doi.org/10.1093/aob/mcp197