No flying foxes, no durians

Study shows that decline of species affects fruit production

PETALING JAYA: Flying foxes are disappearing from our forest, being killed as pests and for exotic meat. And this could hit the multi-million ringgit local durian industry.

Flying fox specialist Dr Sheema Abdul Aziz said the decline in the number of these fruit bats, also known as keluang in Malay, could lead to fewer or poorer quality of durians.

In a research conducted by Dr Sheema and her team, it was found that the giant bats played a crucial role in durian pollination.

“People believe flying foxes eat the durian flowers. However, our study showed that the bats do not destroy the flowers but merely drink the nectar by licking it.

“The pollen from the flowers sticks to its fur while it feeds on the nectar. The pollen is transferred and cross-pollinated when it moves to feed on other trees,” she said.

She said the cross-pollination, from flower to flower of different plant of the same species, is essential to the production of healthy fruit.

The study on this species of bats was made possible with camera traps placed on durian trees in Pulau Tioman, Pahang.

Previous scientific studies had also shown that bats were the most effective pollinators of durian trees.

“The durian industry owes a huge debt to these bats,” said Dr Sheema.

Flying foxes are generally considered to be agricultural pests.

These bats are also hunted and sold as exotic meat. The Chinese believe the bats have medicinal value and can help cure respiratory problems like asthma.

As such, the bats have become a rare sight in orchards across Peninsular Malaysia.

Dr Sheema said that aside from flying foxes, smaller cave bats ( Eonycteris spelaea) also play a big role as pollinators of durian flowers but their population is also being threatened by quarry activities of limestone karsts for cement and marble.

“In Thailand, durian farmers are manually pollinating their trees in areas where there are no bats to help them. The job is expensive and dangerous,” she said.

University of Nottingham Malaysia associate professor Dr Ahimsa Campos-Arceiz, who co-authored the study, hopes the findings would bring urgent attention to flying foxes conservation in SouthEast Asia.

Island flying foxes, of the Pteropus hypomelanus species, and the Malayan flying foxes ( Pteropus vampyrus) are classified as “endangered” under Malaysia’s National Red List.

Worldwide, flying foxes are also severely threatened due to over hunting and deforestation.

Orchard owner Hapsah @ Apisah Abdul Manap said they used to see flying foxes in large numbers across Pulau Tioman but now, there are only occasional sightings of a flock of 20 to 30 bats.

She said it was common to see these giant bats during sunsets two years ago but not anymore.

The durian harvest in her orchard in Kampung Juara has also dropped in the past years,

Desaru Fruit Farm director Steve Er said they put nets to catch bats which ate their crops, especially fruits like water apples (jambu air).

He did not think the poor durian harvest was due to the decline in the number of bats.

Four orchard owners told The Star that this year’s durian harvest dropped between 30% and 80% compared to last year. However, they blamed the prolonged rainy season for the poor yield.