The Buddhist temple at Khao Chong Phran 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.
The value of Khao Chong Phran’s bats goes far beyond guano sales, though this is the most noticeable contribution that people see. Our video shows workers bringing bags of guano from the cave, dumping it on a floor where it is graded for quality and loaded into labeled bags for sale, mostly hauled off by the pickup load by wholesalers, but also sold to some local residents. Harvests occur once a week under strict supervision by monks and town officials.
Recently, a team of U.S. and Thai scientists collaborated on a study of these bats at Khao Chong Phran Cave, investigating their value in controlling white-backed plant hopper pests that attack rice. Although these bats feed on a variety of pests, including moths, the scientists concluded that the bats’ impact in reducing just this one pest was even more valuable than their guano production. Based on this research the bats from Khao Chong Phran Cave are Wanger et al 2014_Bat pest control Thailand in addition to the guano sales.
The spectacular bat emergences also attract many tourists, additionally supporting the local economy, as can be seen by their popularity in local business advertising.