Khao Chong Pran’s Bat Economics

Poachers were killing huge numbers of Khao Chong Pran’s bats and selling them to restaurants until guards were hired to protect the bats. In Thailand bats were killed for the restaurant trade before a law made it illegal.

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.



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Thailand Bat Cave Revisited

Merlin meeting with the head monk at Wat Khao Chong Pran who was happy to see him again.
Merlin meeting with the head monk at Wat Khao Chong Phran who was happy to see him return.

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.

Merlin at the cave entrance with our guide Pongsanant interpreting, while he explains to the head guard and a monk which trees and vines need trimming for the safety of the bats as they emerge each night.

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.







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Angkor Wat and Bats

Angkor WatLiterally 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…)

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Bat caves of Battambang, Cambodia

Battambang Bat Cave
Wrinkle-lipped bat emergence at one of the caves (Tarum) in Battambang, Cambodia

We spent two nights at the Battambang Bat Caves in Cambodia to photograph the incredible emergences of the Asian wrinkle-lipped bats (Chaerephon plicatus). With help from Thona, our colleague and interpreter, Merlin interviewed the owner of the guano harvesting permit for one of the caves (he called it Tarum). He advised the man to never again use pesticides inside the cave (apparently to kill insects that bothered the guano collectors) and recommended removal of a large dead tree in the emerging bats’ flight path. The tree was causing a traffic jam of bats that greatly increased injuries and predation. This was done immediately. (See the remaining stump, lower left of photo).

Merlin interviewed the guano miner of the Tarum bat cave, Battambang, Cambodia
Merlin spoke to the owner of the guano harvesting permit for the cave he called “Tarum” in Battambang, Cambodia


Jeff Acopian videotaped the bat-watching tourists. Just before the emergence, I perched myself on the small hill under the entrance to photograph the bats. An incredible thunderstorm came through, turning my umbrella inside out. Once it passed, the bats finally emerged. At this same time, Merlin took shelter from the rain beneath a ledge in the cave entrance where he had just seen an approximately seven-foot unidentified snake enter a hole about a meter away. He could only hope the snake wasn’t poisonous.



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Cambodian Cave Conservation Workshop

In Phnom Chhnork Cave, Cambodia, our cave workshop group photo was taken outside the 7th century Hindu temple within the cave dedicated to Shiva.
In Phnom Chhngauk, Kampot Province, Cambodia, our cave workshop group photo was taken outside the cave’s 7th century Hindu temple dedicated to Shiva.

Merlin and Dr. Neil Furey, a conservation biologist who’s worked in Cambodia for the past six years with extensive knowledge of SE Asian bats, co-led a cave conservation workshop preceding the Association for Tropical Biology & Conservation–Asia-Pacific Chapter Annual Meeting in Phnom Penh, Cambodia.

Cave Conservation Workshop, Kampot, Cambodia


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Vihear Luong Cave, Cambodia

Merlin sits inside the Vihear Luong Cave entrance photographing the Asian wrinkle-lipped bat (Chaerephon plicatus) emerging at sunset along the high ceiling of the cave.
Merlin sits inside the Vihear Luong Cave entrance photographing the Asian wrinkle-lipped bat (Chaerephon plicatus) emerging at sunset along the high ceiling of the cave.

Following our field trip to the bat farms along the Mekong River south of Phnom Penh in Kandal Province, Merlin and Neil Furey of Cambodia put on a two-day cave workshop for about 10 participants. They lectured with slide presentations to students who already had more than basic knowledge and experience with bats. After lunch, we drove to several caves. At the Phnom Chhngauk limestone mountain the students trapped bats at one of the cave entrances, and Merlin demonstrated bat portrait photography onsite. (more…)

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Bat Pollinators of the Americas Lecture

Merlin presented his lecture, Bat Pollinators of the Americas, to an enthusiastic, sold-out audience today at the Texas Pollinators PowWow, hosted by the Ladybird Johnson Wildflower Center in Austin, Texas, despite a winter weather advisory and freezing rain. He introduced a wide variety of nectar-feeding bats and their ecological and economic contributions to habitats from the Sonoran Desert of the North American Southwest to Central American rain forests, Caribbean Islands and the Andean páramo of South America, ending with a summary of bat contributions worldwide. His next speaking engagement, titled The Amazing World of Bats and a Novel View of Conservation, will be given to a plenary session of the 2015  Asia-Pacific Biodiversity Conference in Phnom Penh, Cambodia on April 1.676A3026

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Fanged pitcher plants and other shelters

Woolly bat inspects fanged pitcher plant for roosting suitability.

Our captive Hardwicke’s woolly bats (Kerivoula hardwickii) preferred pitchers of bat-adapted Nepenthes hemsleyana  plants (see previous blogs), and all woolly bats radio-tracked by Michael and Caroline Schöner in their primary study area consistently returned to the preferred N. hemsleyana pitchers. However the Schöners also found woolly bats in other kinds of plants. Even in their study area they occasionally found an apparently desperate bat roosting in fanged pitcher plants (Nepenthes bicalcarata). This amazing plant relies on a pair of sharp, fang-like, nectar-producing structures above its entrance to facilitate capture of ants that climb down to reach nectar. Approaching ants lose their footing near the tips of the narrowing “fangs,” falling into the water-filled pitchers. Bats can use these pitchers only if they are first drained.  This requires a drain hole near the base. No one yet knows whether these holes are made by inventive woolly bats short on alternative shelter or by birds or other animals, perhaps seeking a meal of captured insects.


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Woolly bat personalities

Caroline Schoner protecting Merlin's camera from rain, while photographing pitcher plants Photo taken by Michael Schoner
Caroline Schoner protecting Merlin’s camera from rain.
Photo by Michael Schoner

Heavy and unpredictable rains made field photography in Brunei difficult. It was a great relief when we were finally able to obtain mealworms so we could keep tiny woolly bats (Kerivoula hardwickii) in our studio. Weighing less than a US nickel, they had been considered too small to be kept in captivity longer than overnight. But under Merlin’s watchful eye, we were able to tame and keep a cast of four. In fact, they turned out to be some of the most fun bats we’ve worked with.  By the second night they had learned to come to our hands for mealworms without our even trying to teach them, and soon learned to get Merlin’s attention when hungry by literally getting in his face.

Hardwicke's woolly bat
Hardwicke’s woolly bat
Woolly bat emerging from a Nepenthes hemsleyana pitcher
Woolly bat emerging from an N. hemsleyana pitcher


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