Thailand
Loss of Nectar Bats Threatens Durian Farmers

The story of Cave Nectar Bats’ contributions and requirements is complex and only beginning to be fully understood. These bats traditionally formed huge colonies in caves, 100,000 individuals in a single cave. However colonies are extremely vulnerable, and few large colonies remain. People commonly set nets over cave entrances, capturing large numbers to be eaten as a delicacy. Also, limestone quarries pose constant threats of permanent destruction of essential caves, and durian growers themselves sometimes kill large numbers.
Documenting Billion-Dollar Bats

Dr. Sara Bumrungsri, a leading bat ecologist, invited us to help document the essential roles of Cave Nectar Bats (Eonycteris spelaea) in pollinating some of SE Asia’s most ecologically and economically valuable plants near Hat Yai in Thailand’s Songkhla Province. We set up our bat photo studio in Sara’s lab at the Prince of Songkhla University, caught two cave nectar bats in mist nets set beneath durian flowers in an orchard, tamed them so they would go about their normal activities in Merlin’s enclosure, then brought them fresh flowers so he could photographically document their importance as pollinators.

Thai Temple Flying Fox Photography

Large flying foxes are always difficult to photograph, especially since they’re intensively hunted over their range. But in Thailand there are still several colonies of Lyle’s flying foxes (Pteropus lylei) that are protected by Buddhist monks. The bats have learned that they are safe when close to the monks’ quarters. And by also remaining close to the monks’ quarters we were able to photograph them much closer than usual, though it still required a great deal of searching for just the right individuals.

Khao Chong Pran’s Bat Economics

The Buddhist temple at Khao Chong Pran is said to have been built largely from guano fertilizer sales. When Merlin first visited the site in 1981, monks were alarmed by a precipitous drop in guano production and asked his advice on the problem. He discovered that poachers were killing large numbers of bats by setting nets over the cave entrance late at night when the monks weren’t looking. The bats were sold to restaurants as a food delicacy. After Merlin convinced the monks to hire a guard in 1981, bat guano sales increased from $12,500 U.S. annually to $89,000 within 10 years, and by 2002, annual sales had reached $132,000 U.S. Recently, the guano producing bats had been in gradual decline despite 24-hour protection by a team of four guards, so Merlin was quite pleased to discover several evenings ago that the most likely cause of renewed decline was simple to remedy–remove gradually encroaching vegetation.

Thailand Bat Cave Revisited

We arrived at Wat Khao Chong Phran unannounced and surprisingly the head monk agreed to see us immediately on the same porch where we met him with Daniel Hargreaves in 2012 (See Sept. 20 blog Guano happens). Merlin even wore the same shirt, his favorite field shirt! Pongsanant, our BatThai guide and interpreter then and now, told us the monk was quite happy to see us again. We had a short visit and were granted permission to go up to the cave entrance to photograph the emergence. We made an appointment to see him the following morning to discuss our findings.

The wrinkle-lipped bat (Chaerephon plicatus) colony had been slowly declining in recent years, despite protection, so Merlin was concerned to discover why. After climbing to the cave we noticed that trees and vines had gradually grown up around the entrance, disrupting the bats’ emergence, as thousands collided with obstacles. We saw clear problems that in other free-tailed bat caves have caused abandonment and reported this the next morning. Merlin was happy to provide an on-site explanation and delighted when the tree trimming was promptly ordered. The cave managers are now aware that this should be repeated every couple of years in the future as a routine part of protection.
Given Merlin’s involvement in gaining the first protection for these bats 34 years ago, he’s especially interested in ensuring their continued safety.

Angkor Wat and Bats
Literally thousands of temple ruins are near Siem Reap to explore, and at least three days is recommended to see most of them. In one day we visited ten, and were pleased to find bats in most of them.
The complex of temples known as Angkor was built from the 9th to 13th century by successive Khmer rulers, and the mother of them all is the Angkor Wat Temple, the largest (first Hindu, later Buddhist) temple in the world. Between the 12th and 13th century, when London had a mere population of about 50,000, it is estimated that Angkor had 1,000,000, making it the largest city in the world at the time. They were the people, under successive Khmer kings, who built these massive construction projects on the scale of the Egyptian Pharaohs’ pyramids.
If you’ve ever seen the Angelina Jolie movie Lara Croft: Tomb Raider, many of the scenes were filmed at Angkor. I join the chorus and recommend you see Angkor Wat before you die!
At nearby Phnom Kulen National Park, we set up a four-panel bat trap over a small stream in the forest for about an hour, and caught five species of bats. (more…)