People often get freaked out when they spot bats. After all, they’re usually linked to vampires and thought to be bloodsuckers. But that idea is just a production of wild imagination.
The reality is, bats are actually the main carriers of rabies, one of the oldest diseases known to humans. And that’s scary because once you are infected and if you are not vaccinated against rabies, you are most likely to die from it.
However, there’s really no need to be scared of bats. Not all bats carry rabies. In the wild, only a small percentage of bats have the rabies virus. A 2011 University of Calgary study found that less than one percent of bats carry rabies.
Despite this fact, the US Centers for Disease Control and Prevention urged people to always treat any direct contact with a bat as a potential risk. But they should not be feared or killed.
In fact, bats deserve some serious credit for their role in food production. Take Enrique V. Cadayona, a 63-year-old farmer from Calinan, Davao City, for example.
His farm isn’t your average farm; it’s an agroforestry setup. Half of his 11-hectare farm is filled with around 30 species of lauan trees, while the other half is dedicated to various fruits like durian, lanzones, and mangosteen.
He has about 100 durian trees. In the last few years, he has noticed that when a lot of bats come around during the flowering season, his fruit production skyrockets. But when there are fewer bats, the yield drops.
During a visit by a group of journalists to the Monfort Bat Sanctuary Cave in the Island Garden City of Samal, owner Norma Monfort explained that the high production of durian in Davao City is attributed to the fruit bats residing in the sanctuary.
At that time, the sanctuary was home to approximately 2.5 million bats, which earned it the Guinness World Record in 2010 for hosting the largest fruit bat colony globally.
“Durian trees depend on bats for pollination during their short flowering periods,” Monfort explained.
Pollination is just one of the several tasks bats do. “I believe bats are very important in farming because they provide several ecosystem services that directly benefit farmers,” says Amy G. Ponce, a zoologist and the project lead of the Integrated Approach in Management of Major Biodiversity Corridors in the Philippines or BD Corridor Project-Eastern Mindanao Biodiversity Corridor” under the Global Environment Facility, United Nations Development Program and Department of Environment and Natural Resources. “They act as natural pest controllers, pollinators, and seed dispersers.”
But that’s going ahead of the story. Actually, bats are classified into two main suborders – microbats and megabats – with over 1,400 species around world.
Microbats are typically smaller, insectivorous bats that depend significantly on echolocation for navigation and hunting during the night. In contrast, megabats, often referred to as fruit bats or flying foxes, are larger and mainly consume fruit, nectar, and pollen. They rely more on their vision than on echolocation and are essential for pollination and seed dispersal.
The Philippines hosts a variety of remarkable microbat species, such as the Philippine tailless leaf-nosed bat (Coelops hirsutus), dusky leaf-nosed bat (Hipposideros ater), fawn horseshoe bat (Hipposideros cervinus), Philippine forest horseshoe bat (Rhinolophus philippinensis), and the great bent-winged bat (Miniopterus magnificus).
“Bats that consume insects play a crucial role in managing agricultural pests during the night,” Ponce remarks. She describes them as nocturnal hunters.
“They use echolocation to find insects in total darkness and consume a variety of night-flying insects, such as mosquitoes, moths, beetles, and other insects whose larvae could turn into agricultural pests,” she emphasizes. “This is especially significant since numerous crop pests are active during the night.
“By preying on adult insects, bats can assist in reducing pest populations prior to those insects reproducing and generating another generation of larvae that can damage crops,” Ponce asserts.
It has been reported that microbats can consume between 40% and 50% of their body weight in insects each night. “For farmers, this essentially represents a form of free biological pest control,” she explains. “It can enhance integrated pest management strategies and may reduce the reliance on chemical pesticides.”
Among the prevalent megabat species are the giant golden-crowned flying fox (Acerodon jubatus), large flying fox (Pteropus vampyrus), and the Philippine bare-backed fruit bat (Dobsonia chapmani).
Ponce notes that nectar- and fruit-eating bats assist agriculture through the process of pollination, which involves the transfer of pollen grains from the male part of a flower (the anther) to the female part (the stigma), enabling plants to produce seeds and fruit. They perform this essential function during the night.
“In this regard, bats serve as the ‘night shift’ of our agricultural ecosystem,” she remarks. “While birds, bees, and other beneficial creatures are active during daylight hours, bats continue to provide vital ecological services throughout the night.”
Ponce references durian as a quintessential example. The case of Cadayona comes to mind. “Durian flowers bloom at night, and bats that visit these flowers for nectar can significantly contribute to pollen transfer,” she states.
Bats are also linked to the pollination of mangoes and mangosteens, in addition to agricultural crops such as agave, kapok, and certain wild banana varieties. The presence of bats is a key factor in the successful banana cultivation in the Davao region.
According to Ponce, the mechanism by which bats pollinate is relatively straightforward. “When nectar-feeding bats approach a flower to consume nectar, their face, head, chest, and fur come into contact with the pollen of the flower,” she elaborates.
“The pollen adheres to the bat’s fur,” she continues. “When that bat subsequently visits another flower, some of the pollen is transferred to the reproductive structures of the new flower. This process enables bats to promote cross-pollination, which can ultimately lead to fertilization and the development of fruit.
“I think it is important not to generalize that bats are the main pollinators of all tropical fruits,” Ponce clarifies. “Their importance depends on the crop, the bat species, and the locality.”
Bats are particularly fascinating as pollinators due to their capacity to cover extensive distances in flight. “Their ability to visit flowers from various trees within a single night enables them to facilitate pollen transfer across a relatively broad area,” states Ponce.
Regarding their flying capabilities, most bats typically travel short distances of under 320 kilometers for daily foraging or during seasonal migrations. Consequently, they serve as exceptional seed dispersers.
“Generally, there are two ways they do this,” Ponce says. “For fruits with relatively large seeds, a bat may pick up the fruit and carry it away from the parent tree to a feeding area. It eats the pulp and later drops the seed. For fruits containing smaller seeds, bats may swallow the seeds together with the fruit and later excrete them in another location.”
The ability of bats to fly over significant distances allows them to carry seeds far from the parent plant. “This minimizes competition between young plants and the parent tree, facilitating the colonization of new or disturbed areas,” Ponce notes. “This is why fruit bats play a crucial role not only in agriculture but also in forest regeneration and the restoration of degraded landscapes.”
In addition to the various services they provide, bats are also the primary source of guano, or bat droppings. “Bat guano serves as an excellent organic fertilizer due to its rich content of essential plant nutrients, especially nitrogen, phosphorus, and potassium,” she states. “These nutrients play a crucial role in various aspects of plant growth, such as vegetative development, root formation, flowering, and fruit yield.”
However, she cautions farmers against the excessive application of highly concentrated or fresh guano on their crops. “It is vital to ensure proper processing, composting, and adherence to suitable application rates,” she advises. “Thus, while I would characterize bat guano as a valuable natural fertilizer, it should not be applied indiscriminately.”
Unknown to many, bats are the frontline warriors against climate change. “They are pollinators,” said Monfort. “They maintain so many species of plants, trees and fruits that are habitats for other important species. If we lose them completely, we stand a great chance to never again enjoy the wonderful fruits and plants we have today.”
Unfortunately, since bats are misunderstood and most people don’t care about them, they are now considered threatened species. “The threat to bats in the Philippines is quite serious considering that very little literature and research have been published about them,” Monfort lamented.
In the Philippines, there are some laws that prohibit the possession, catch, kill or trade of bats. Republic Act No. 9147 or the Wildlife Resources Conservation and Protection Act of 2001 prohibits doing all these.
Penalties for these crimes range from imprisonment of between 10 days and 12 years, and/or a fine of one thousand pesos to one million pesos, depending on the nature of the offense and whether the wildlife species is threatened.
