The world’s largest known population of Geoffrey’s Rousette fruit bats (Rousettus amplexicaudatus) is found in the Monfort Bat Cave located in Barangay Tambo, Samal Island, near Davao City in southern Philippines. This fact was established in a scientific survey conducted by American bat scientists Dr. Merlin D. Tuttle and Dr. David L. Waldien under the auspices of the US-based Bat Conservation International (BCI) and was officially recognized by the Guinness World Record in 2010. The cave assessment, conducted in June 2006, established that there are approximately more than 1.8 million bats living in the cave located within the private property of the Monforts over the past six decades. The Monfort Bat Cave is thought to be the only remaining major roost-site of bats that is protected on Samal Island. The scientists also surveyed a number of the more than 70 caves in Samal known to be shelters of bats and found evidence of intense human hunting of bats for food at caves that once housed large population of bats.
With human disturbance in many of their natural roosts, bats on Samal Island and surrounding islands appear to have converged and now roost in large numbers in the protected Monfort Bat Cave where the bat population has increased considerably in recent decades. To protect the Monfort Bat Cave and conserve the bat population on Samal Island which plays a critical role in the pollination of economically-important fruits in the region, such as durian and wild banana, Dr. Tuttle and Dr. Waldien recommended key management measures. The scientists urged the Monforts and local environmental groups to conserve the caves, to launch an active education and awareness-raising campaign among policy-makers and the general public on the life of bats, their habitat, their role in the ecosystem, as well as their economic value in the region’s production of high-value fruits.