Bats of Miagao. Part 1

Living in the shadow of the enchanted bubog trees and 7,000+ fruit bats 


Jonathan R. Matias
Sulu Garden
Miag-ao, Iloilo Philippines 5023

with Katherine P. Sarabia and Coleen P. Sucgang

Photographs by Nick Foster. Aerial drone video courtesy of Essen Ferranco and Ramil Naciongayo.


Bats living inside the church belfry, inside roof of houses and under bridges used to be commonplace. But, with better housing construction, there are less and less places for bats of all kinds to roost. Recently, the town of Monster –Yes, this is the town’s real name– in the Netherlands just finished constructing a bridge over the Vlotwatering River for both pedestrians to cross and for bats to roost [1]. It is hoped that the bridge will be home to bats that will feed on tons of insects similar to the 1.5 million Mexican free-tailed bats that live under the Congress Avenue Bridge in Austin, Texas. Fruits bats suffer the same fate of a different kind. As urban sprawl and reduced forest cover starts to limit their habitats, fruit bats will soon end up in the endangered list. In the Philippines, fruit bats in Mambukal in the neighboring Negros Island have a sanctuary of their own in the forest. Other islands with roosting bats developed sanctuaries to save the population.

What makes Miag-ao’s fruit bats so different? They live within a real community of people, with an entire village practically under the bat roosting trees. And they have coexisted for the last 70 years; perhaps, longer than that according to other residents. Next to the Church of Miag-ao, one of the four UNESCO Heritage Churches in the Philippines, Miag-ao’s bat population is among the many favorite local tourist attractions.

Photo from drone photography by Essen Ferranco.

Photo from drone photography by Essen Ferranco.

Look at the picture above. Every tree is green except that brown patch in the center of the aerial photo of the town center. That brown patch is not because of brown leaves. It is the color of 7,000+ fruits bats that are, for lack of a better description, simply ‘hanging out,‘ waiting for dusk to fly out of the centennial bubog trees. North of that patch of brown is the Miag-ao Municipal Hall. About 10 meters in all directions from the center of the patch are homes, small restaurants, a billiard hall, and dormitories for university students. At least 500 people live around that patch of brown in two villages (barangays). What is more amazing is that practically under and around the bat trees are about 150 residents of barangay Bolho. The first article we have ever seen about the bats of Miag-ao came from the blog article written by my son, Jason, based on his 2014 visit to Miag-ao [2].

See this video for the ‘home trees’ of Miag-ao’s fruit bats HERE.

The Bats

We have been able to confirm the species as Pteropus hypomelanus with the help of Philippine Bat Champions [3]. More information about this species can be found in the IUCN Red List of Threatened Species [4]. Sulu Garden’s Conservation Project described P. hypomelanus as shown in the entry below [5].

Photos by Nick Foster.

Photos by Nick Foster.

“One of the most unusual new arrivals in Miagao is the fruit bat, Pteropus hypomelanus, also commonly known as the common island flying fox. They are the more gregarious types, normally congregating in trees with populations ranging from a few hundred to a few thousands. The Miag-ao fruit bats appeared on the scene in 2003 (some say as early as 2001) roosting in a giant hundred + year old bubog tree (also called skunk tree) 300 meters from the beach and in the midst of heavily populated area of town. Where they came from is unknown, why they stayed or chosen Miag-ao is even more a mystery. But, the population increased in numbers and became the new residents.”

We were actually wrong in our estimation of the appearance of the bats in the Miag-ao scene. As you will read below, recent interviews conducted with longtime folks living under the bat trees showed that the population had been up the tree since 1958. Perhaps the population was few in numbers back then to be noticeable by those folks like us living away from the roosting environment. The presence of the bats created some debate many years ago whether to drive them away or protect them. However, the municipality decided to pass an ordinance declaring the area around the bubog tree a bat sanctuary.

Fruit bats are relatively benign creatures of the night and adapted to feeding on the juices of fruits. I always thought that they eat the whole fruit. I was mistaken. These bats have sharp fangs to bite the fruit, but actually sip the juices that come out rather than eating the entire fruit. They do occasionally swallow the seeds and mostly pass the seeds through their digestive system. In that way, the bat poop helps in disseminating seeds to different areas. Without bats, many of our native fruit trees will have little chance of having their seeds dispersed.

I know you are so excited to know more about these fruit bats. So, here are few more fruit bat trivia for you [6].

  1. They have the best overall vision of all the world’s bats.

  2. They have unusually long tongues that unroll during feeding and roll back into the rib cage when not eating.

  3. In each roosting trees are sub-colonies that comprise one male and typically eight females (Male fruitphoto bat trivia bats must be among the sexually exhausted organism in the planet)

  4. They typically roost in high trees to avoid predators, such as cats, snakes and other large mammals.

  5. They have only one young at a time.  Typical gestation period is six weeks.  Until they are able to fly on their own, the babies cling on the underfur of the mother during flight.

  6. Last and most kinky – fruit bats like oral sex [7].  I am not kidding!  They do it before, during and after sex.  Scientists are still confused as to whether fruit bats do it for fun or do it for “stimulation, lubrication or sanitation.”  Maybe they just simply enjoy it?

The Roosting Trees

The bubog tree (also called calumpang, skunk tree) is scientifically referred to as Sterculia foetida. This tree has a wide range of habitat from the Middle East and as far as South East Asia and the Pacific islands. It is a soft wood tree that can grow to over 115 feet in height. Coincidentally or it may be just fate that the genus Sterculia was named after the Roman god, Sterquilinus, the god of manure [8]. I think this is so appropriate since bats do make plenty of them. Just stand under the bubog trees and you’ll know what I mean.

The bubog plant’s flowers and fruits.

The bubog plant’s flowers and fruits.

The Bubog Trees.

The Bubog Trees.

Bubog trees are considered enchanted in most parts of Panay Island. Perhaps even much more so in Miag-ao. There are two bubog trees growing side by side located exactly at the boundary between Barangays Sapa and Bolho. The locals say they are considered centennial trees, but no one seems to know exactly how old they are. But, the elders would regale at telling stories of enchantment and hauntings that took place in the past. I’ll tell you about that another time. Maybe this is part of the reason why the folks living under and near the bubog trees leave the bats alone to their own devices, despite the smell and the noise.

The majestic bubog trees viewed from under the bat roost. See the video by Coleen P. Sucgang HERE and also the video by Katherine P. Sarabia HERE.

Why do these fruit bats like the bubog trees?

Fruit bats prefer to live in close proximity to a body of water, such as rivers or by the sea. They also prefer tall trees to escape from predators. Perhaps the enchanted bubog trees just happened to be the biggest tree in the neighborhood. Also, they might prefer to feed on the fruits and seeds of bubog, though likely it is a secondary reason since fruiting is not year-round for bubog trees.

Is the bubog tree in town attractive to fruits bats because it is enchanted?

People here tend to think so. One local folklore is that Princess Olayra anchors her golden ship along the creek (perhaps it was a river long ago) beside the bubog trees before going out to the sea. There were sightings of a white house with bright lights that appeared with Caucasian folks inside inviting out-of-town visitors to come in for dinner. Then later, the white house will vanish into thin air. Or, more recent stories by the people living near the bat trees hearing the sound of an anchor being lifted out of the water in the middle of the night, of abandoned machineries and parts that failed to work beside the bubog trees and magically lifted in the mist. Folks say that the bubog trees are home to underworld creatures and one must seek permission first by whispering ‘tabi-tabi po” before coming close or taking anything from the tree. And there are plenty more of those stories to share. One certain advantage for the fruit bats—people leave them alone most of the time.

Bat People

Can you imagine living under or even close to 7,000+ bats? The smell of bat poop or guano can be overwhelming. Very likely the only one pleased about that is Sterquilinus, the Roman god of manure. The amount of fruit bat poop at the bottom of the hill is much less than I would have expected compared to going into bat caves. It might be because rain and erosion kept washing them off the ground, though the distinctive odor remains in the air.

The community and people living under the bat trees.

The community and people living under the bat trees.

What do the people living under the bat trees have to say?

We went to Barangay Bolho and asked. It’s the only way to find out! Here is what they said [9].

• Fruits bats have resided in the tree for more than 50 years. Earliest sightings date to 1958, as recounted by a longtime resident.

• Other animals aside from the fruit bats also inhabit the bubog tree (or at least near it) such as sawa (pythons and other snakes) and halo (monitor lizard).

• A few fruit bats occasionally circle around the bubog tree. It is said that when a person comes near the base of the bubog, those bats in close proximity would transfer to farther branches. However, if the species makes contact with a person and become agitated (e.g. from being touched), they will react and/or bite the agitator.

• Droppings and urine fall on top of the roof of their houses. Their excretions stain clothes that are left outside to dry. Urine can sometimes be mistaken as rain (NOTE: Synchronization of urination maybe is occurring as a group behavior).

• At night time, fruits and seeds coming from the bats fall on rooftops. (NOTE: The fruit bats bring food back to the tree. This may indicate the adults feed their olders bats and young as they are not able to fly).

• Despite strong winds and unfavorable conditions, the fruit bats don’t seem to migrate away from the bubog tree (e.g., during Typhoon Haiyan, the bats remained in the tree).

• The largest bat (presumably an Alpha male or possibly the bat elder) in the roost is said to remain in the tree after the mass migration at dusk. Accounts from residents say the Alpha calls out to the other fruit bats around 1:00AM and at 5:00 AM. The Alpha’s call is said to be a loud howl-like shriek comparable to the barking of a dog. (NOTE: Departure time from bubog tree to the direction of Antique Province – about 6:00 PM; Arrival time from Antique to the bubog tree – 5:00AM). The Alpha fruit bat according to a witness is around twice as big as the regular fruit bat.

• The residents do not seem to have any major difficulties living with the fruit bats. They are accustomed or are well-adjusted to their bat neighbors.

• Some residents cook and eat the bats that fall off the tree because of fatigue or heat stroke during summer. Testimonies say the fruit bats taste like chicken.

• Dogs eat the corpses of dead bats once they fall from the bubog tree.

• People pick up dead fruit bats and hang them on the nearby tree branches. Some children play with them with lipaks (sticks). There are no accounts of the locals burying them.

• A resident has a garden at the base of the bat tree (composed mostly of sweet potatoes, bananas, and others ornamental plants). She has not encountered problems from the fruit bats. However she experienced headaches after trekking down. She ascribes the headaches to the “supernaturals” who are trying to pay her a visit.

• A few residents believe that the fruit bats came from Miag-ao Church when it was partially destroyed. (NOTE: An earthquake occurred in 1948. The church reconstruction began in 1960 and completed on 1962. The earliest recollection of the residents seeing bats in the bubog trees was in 1958).

• The bat people say there are many tumao (supernatural beings). They show their manifestations or presence through unsettling and eerie feelings as well as general discomfort or uneasiness (malaise) to people. According to the elderly residents, the fruit bats are the “pets of the tumao.”

• On Good Friday, the bubog tree is clear of fruit bats.

• At the barangay creek in the early morning, a “golden boat” docks and the anchor chain is said to echo loudly enough for the whole barangay to hear.

The billiard hall beside the bat trees. Photo by Nick Foster.

The billiard hall beside the bat trees. Photo by Nick Foster.

Fruit bats, bubog trees and medical issues

This section is about good news and bad news. Let’s start with the good news.

It is not suitable for construction because it is soft wood and prone to fast deterioration, particularly in the tropics. Bubog trees turns out to have a plethora of uses. Its leaves, sap, fruit and bark have a wide range of uses [10, 11]. In Philippine folklore, bubog is used for a variety of ailments. Here is a list for you.

• Decoction of bark used in the Philippines for dropsy and rheumatism; as aperient, diaphoretic, and diuretic.
• Decoction of leaves as wash for skin eruptions, used for difficult labor, and as astringent.
• Fruit contains oily kernels which are edible and laxative when raw.
• Paste of oil applied to pruritic conditions.
• Oil from seeds given internally for itching and skin diseases; also applied externally as a paste.
• In Java, decoction of fruit used for blennorrhagia
• In Ghana, seeds used as purgative.

In biomedical sciences, quite a number of research articles have been published that explain the above folkloric uses of bubog plants. Here are a few just in case you are medically inclined:

• CNS Depressant / Anti-Inflammatory / Leaves: Extract of leaves on various animal models showed CNS depressant activity and anti-inflammatory activity. (This would explain the use of leaves to treat skin eruptions)

• Mitogenic Activity: Sterculic acid isolated from Sterculia foetida oil was identified as one of the mitogenic principles.

• Gum / Controlled Release Excipient: Sterculia foetida gum was studied as a hydrophilic matrix polymer for controlled release preparations. Results concluded it can be used as a controlled release matrix polymer.

• Gum / Ophthalmic Drug Delivery System: .Study of SF gum showed it could be good polymer candidate for the formulation of different ocular dosage forms like solution or viscous solution (drops), nanoparticles, nanosuspensions or suspension, micro or nano emulsion, lotion, gels, hydro gels, in-situ forming gels, ointment, inserts, films, minitablets, etc.

• Phytochemicals: Study yielded two new flavonoid glycosides and a new phenylpropanoid glucose ester from the leaves of Sterculia foetida.

• Antimicrobial / Cytotoxicity / Phytochemical Screening: Study yielded tannins, 2-deoxysugars, leucoanthocyanin and benzopyrone nucleus. Results showed extracts with antibacterial activity, inhibiting S aureus and E coli. Antiprotozoal assay also showed inhibition of growth of Entamoeba histolytica. In an in situ cell death detection kit, it showed apoptotic-like changes.

• Toxic and Anti-feedant Activities: Study of the seed crude extract showed S. foetida acted as insecticide to Asian armyworm, S. litura and as anti-feedant to the semilooper, Achaea janata, indicating a dual mode of action against the different pest larvae treated.

• Sterculic Oil / Anti-Obesity: Oil extracted from the seeds of the Sterculia foetida tree may reduce belly fat and help protect against obesity-related issues. The fatty acid content of sterculic oil may inhibit the action of an enzyme associated with insulin resistance, which may indirectly reduce belly fat. The data from rodent studies suggest a potential for developing a natural nutritional supplement.

• Antioxidant / Seed: Study evaluated the phenolic content and antioxidant activity of methanol extract of seeds of S. foetida. The extract yielded 9.5% crude material with a total polyphenol content of 14.32%. Antioxidant activity was assessed by DPPH, ferric reducing power and ABTS.

• Nasal In-situ Gel Using Sterculia foetida Gum as Natural Mucoadhesive Polymer: The nasal mucosa is considered a potential administration route for faster and higher drug absorption. Study shows the S. foetida gum can be successfully used as a mucoadhesive natural polymer in developed thermoreversible mucoadhesive nasal gel of zolmitriptan for use in migraine therapy.

• Anti-Convulsant: Study evaluated the anticonvulsant property of aqueous extract of Sterculia foetida in pentylenetetrazole (PTZ) and MES induced convulsions in experimental rat models. Results showed significant decrease in duration of tonic clonic seizures and recovery time in the MES model. There was delayed onset of seizures and reduced duration of convulsions in the PTZ model.

• Nanoparticles / Antimicrobial / Leaves: Study reports on the extracellular silver nanoparticles synthesis using young leaves extracts as reducing agent. The bio-functionalized silver nanoparticles showed admirable antimicrobial effect. Results suggest an eco-friendly synthetic procedure with a potential for many pharmaceutical applications.

• Anti-Diabetic / Antihyperlipidemic / Leaves: Study of a methanolic extract of leaves in alloxan-induced diabetic albino rats showed significant antidiabetic and antihyperlipidemic effects with restoration of metabolic changes.

We all know that fruit bats are important in disseminating seeds of fruiting plants, particularly our native plants. Now for the bad news. Rabies, SARS, NIPAH, Marburg and Ebola virus epidemics of recent years originally came from fruit bats. Like many other animals (such as rats, mice, dogs) fruit bats are reservoirs of viruses that rarely harm them directly. Why is it an evolutionary advantage for some animals to harbor viruses? Science has yet to figure that one out.

“Bats and other species that chronically harbor viruses, such as rats or mice, are known as disease reservoirs. Most of the time, these reservoirs stay intact, with infected animals rarely showing symptoms of disease. But sometimes they leak, letting a virus infect new, much more vulnerable species. This is almost certainly what happened with the ongoing Ebola outbreak in West Africa, which began with a trickle in December and has since infected at least 8,900 people and killed more than 4,400. Scientists suspect bats are to blame for this epidemic, which has overwhelmed Guinea, Sierra Leone, and Liberia”
—from [13]

Bats, like other bush meat (gorillas and monkeys), are eaten in Africa and other places as well. Although bats are also eaten in the Philippines (and one of the reasons for the near extinction of some bats species), disease outbreaks directly related to bats have yet to occur here or perhaps simply never made it to an epidemic scale. Fruit bats in Miag-ao are also consumed, though this rarely happens these days. Nevertheless, diseased bats consumed by dogs and passed on other animals may yet rear its nasty head one day.

The Future of the Bats of Miagao

Photo by Nick Foster.

Photo by Nick Foster.

The bats and the people living in their shadow are in some sort of balance, for now. However, these bats became quite more visible as the population exploded back about a decade ago. As the local residents also increase their population, conflict will be expected to come as the needs of the people and the bats collide at some point in time.

Is the bat population really increasing? I have walked the environment of the bats for the last two years and noticed something new. The bats are beginning to colonize the other trees around the bubog trees. The centennial trees are already crowded with bats and the leaves are fewer. Perhaps the new leaves could not grow due to the damage created by bats perching on the branches and constantly moving about. Will these trees die? I am afraid these two trees will not last very long. They are quite old, but their demise might be accelerated by the bat’s population explosion.

Tourism potential

Nick Foster and a friend taking photos of fruit bats.

Nick Foster and a friend taking photos of fruit bats.

Miag-ao has many natural splendors, but most require a hike up the hills and mountains. Besides the sea, which might be a common sight for most, the bat roosting trees offer an adventure ‘into the wild side’ but within a 5 minute walking distance from the nearest bus, jeepney or tricycle stop. How to develop this into a tourist attraction while conserving the bats of Miagao is going to be a challenge.


[9] Interviewed: Gloria Nopueto, Ruello Nopueto, Dante Maza, Gloria Nopueto, Ruello Paulma, Dante Maza (39 years old, former San Miguel Beer Factory worker and presently works as a driver), Lovella Francisco-Paulma, Gloria Nopueto (71 years old, housewife, not originally from, married to a resident, Bernardo Nopueto, 68 years old, carpenter]), Ruello Paulma (68 years old, carpenter).

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