Flying foxes pollinate regionally important fruit crop
By putting camera traps in durian trees on Tioman Island, Malaysia, researchers collected video evidence showing the island flying fox (Pteropus hypomelanus) pollinating durian flowers, leading to the production of healthy durian fruit. The study has just been published in the journal Ecology and Evolution.
The spiky tropical durian fruit is highly prized throughout its native region. A ubiquitous icon of Southeast Asian culture, it is also a lucrative industry, generating millions of US dollars in local and international trade. And these economic profits owe a huge debt to bats.
Commonly referred to as flying foxes, 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.
On top of this, 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 severe declines in flying fox populations worldwide.
Yet these bats actually play very important roles as seed dispersers and pollinators in rainforests, especially on islands. The disappearance of flying foxes could thus have disastrous repercussions for tropical ecosystems. Now, this international team of researchers from Malaysia, France, India, and Thailand, in collaboration with Tree Climbers Malaysia, has found that Southeast Asia’s durian supply could be affected too.
Dr. Sheema Abdul Aziz, who led the study in Malaysia as part of her PhD under the Muséum National d’Histoire Naturelle (France), said: “These are very important findings because they shed more light on the crucial ecosystem services provided by flying foxes. Previously it was known that the smaller, nectar-feeding bats are pollinators for durian – but many people believed that flying foxes were too large and destructive to play such a role. Our study shows the exact opposite: that these giant fruit bats are actually very effective in pollinating durian trees.”
According to Dr. Sheema, who is currently President of the Malaysian NGO Rimba, and a Visiting Academic at the University of Southampton, cave nectar bats are already being affected by limestone quarrying. How much has durian production already suffered due to declines in bat populations?
This is something Rimba plans to investigate further to initiate conservation action. “The island flying fox is already classified as ‘Endangered’ on Malaysia’s National Red List,” Dr. Sheema explained. “We want to reverse this downward trend. If people end up hunting flying foxes to extinction, it’s not hard to see that there could be serious implications for Southeast Asia’s beloved King of Fruits.”
Access the article here:
Aziz SA, Clements GR, McConkey KR, Sritongchuay T, Saifful P, Muhammad Nur Hafizi AY, Campos-Arceiz A, Forget P-M, and 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: doi: 10.1002/ece3.3213.
For further information, or to obtain versions of the press release in Bahasa Malaysia or French, please contact Sheema.
Update 6 October 2017:
Our press release has been picked up by local and international media! Check out the extensive coverage below (in English, Malay, and Mandarin):
Dwindling flying fox numbers a thorny issue (video story)
Malaysia Gazette: Raja buah terancam jika keluang pupus
Berita Harian (Singapore): Industri durian Malaysia terancam dek kelawar berkurangan
The Malay Mail Online: Fruit bat decline turns durian harvest into thorny issue
National Geographic: World’s smelliest fruit might not exist without this giant bat
Podcast of Sheema’s radio interview with Business FM station: The role of flying foxes in durian pollination ecology
Update 10 October 2017: Our study just got a brief mention in a Nature News article about another recently published study that sequenced the entire durian genome: How the durian got its sulfuric stench
Update 28 December 2017: Full-page infographic by Singapore’s Straits Times featuring our study: What have bats got to do with durians?
Update 19 February 2018: Generous coverage by Jeremy Hance for The Guardian‘s ‘Radical Conservation’: World’s most controversial fruit may depend on giant bats for pollination
Other coverage online:
Asian Scientist: Durians depend on endangered fruit bats