Bats in Focus: Francis

08.19.26

By Wendy K. Probst

Birding can easily become a life-long preoccupation. And when you go searching for birds, in less obvious, duskier, “cavey” places, sometimes life gives you (pause for effect) bats. What are the key ingredients to capturing both in a vivid, visual format? Flight, light, timing, a sense of adventure, and a sizeable portion of patience.

Enter: Charles M. Francis, a wildlife biologist with the Canadian Wildlife Service, author, and adjunct research professor at Carleton University whose long field career has included describing several new bat species. He has collaborated with fellow mammal enthusiasts to author field guides to the Mammals of Borneo and Southeast Asia and has contributed to the North American Bat Monitoring Program (NABat). Charles’s extensive research on bat taxonomy, distribution, monitoring, and conservation has appeared in journals including Journal of Mammalogy, Zootaxa, and PLOS ONE. He’s also a longtime bat photographer and contributor of wildlife images that reflect decades of dedicated fieldwork. And, this is key, he has an infectious fondness of bats. And birds, which is where it all started.

Why bats?

I have been interested in wildlife ever since I took up bird-watching as a young child, when I had to persuade my father to drive me to the top local birding sites in Ottawa, Canada on weekends. (He was very pleased when we met a birder just down the street who was keen to bring me birding with him!)

I developed an interest in Asian bats in the summer of 1979, when I had a chance to spend a month netting and banding birds at Pasoh Forest Reserve in peninsular Malaysia, where we incidentally captured many species of bats in our nets at dusk and dawn. Two years later, I started a three-year placement as a Cuso International volunteer with the wildlife branch of the Sabah Forest Department, studying birds — particularly the nesting ecology and distribution of the Edible-nest swiftlet’s whose nests are harvested for sale to make birds’ nest soup.

These birds nest in large caves, which, of course, were also occupied by many species of bats. I developed a new design of harp trap using four banks of fishing lines, instead of the original one or two, which proved to be very effective at catching a wide variety of Asian bats. Small insectivorous bats manage to fly through one or two layers of the trap before sliding down into the bag at the bottom which has plastic flaps to stop them from climbing out. These were so effective, I caught many species not previously known to occur in Borneo, including several species that proved to be new to science (these traps are now widely used by bat researchers throughout Asia).

Photographing bats was particularly challenging in the era of slide film, as I never knew whether my photos turned out until they were developed, sometimes weeks later. Few of those early photographs have stood the test of time, but they were nevertheless very useful as reference material.

The Story Behind the Photo

A portrait of a tailless roundleaf bat (Coelops frithii) from Thailand taken in 2006 a few years after I started using digital cameras. These fascinating small bats remain very poorly known in South-east Asia, with relatively few records, possibly because their extremely high echolocation calls, sometimes over 200 kHz, enable them to easily detect and avoid most nets and traps.

You collaborated on some very specific field guides to Asian mammals. How did that happen?

While in Sabah, I soon got to know most of the other wildlife biologists, including John Payne, who had been surveying primates and other larger mammals, as well as Karen Phillipps, a very talented natural history artist. John and Karen had been thinking about a field guide for a while, but when I offered to write the section on bats (nearly 40% of the species in the book) this was the incentive for us to get started. With support from the staff of the wildlife branch, we set out to capture as many of the small mammals and bats as possible for Karen to draw. With a couple of visits to the Natural History Museum in London to see specimens of species we hadn’t captured, we were able to publish A field guide to the Mammals of Borneo in 1985, the first fully illustrated guide to all the known mammal species of any region in Asia, including 93 species of bats (though subsequent research has brought the total to over 100 species).

Later, when working in peninsular Malaysia and Laos, I found there was also a need for a similar, comprehensive guide to mammals in mainland Southeast Asia, so I prepared a Field Guide to the Mammals of Mainland Southeast Asia with support from New Holland publishers and several very talented artists, though this time they had to work largely from photographs and museum specimens as we didn’t have the chance to work together in the field.

How did the birds lead you to the the bats in Malaysia?

Gomantong Caves is one of the most spectacular caves in Sabah, Malaysia, being home to over one million bats of many different species and similar numbers of swiftlets of four different species. I spent many months working there in the early 1980s, following the nesting cycle of the swiftlets, and I try to return there every time I’m visiting Sabah. This is a challenging cave for photographing bats in flight as the caves are so big. Many of the bats live in the lower cave, Simud Hitam, which is up to 50 meters tall in some places. Most of the bats fly high along the ceiling of the huge, 10-meter-high entrances. However, there are several smaller entrances to the caves, where it is possible to set up a camera system with a trip beam and flashes to capture photos in mid-flight.

The Story Behind the Photo

This photo shows the distinctive “wrinkled” lips that give the wrinkle-lipped bat (Mops plicatus) its common name as well as its narrow wings and the thick protruding tail of bats in the family Molossidae.

The Story Behind the Photo

On many nights, most of the wrinkle-lipped bats fly out from the cave before dark in an impressive stream, heading out to distant feeding grounds that may be tens or hundreds of kilometers away. This attracts predatory birds such as this Wallace’s hawk-eagle, allowing me to combine my interests of bird and bat photography in the same picture.

How on earth did you learn to photograph bats in flight so well?

I had long admired many of the flight photographs I had seen from pioneering bat photographers such as Merlin Tuttle. In 2014, I signed up for an afternoon workshop organized by Merlin and bat researcher and photographer Brock Fenton in conjunction with the North American Symposium on Bat Research to learn the basic techniques. But it was a couple of years later that I finally started to acquire the necessary equipment, particularly infrared trip beams and a set of flashes. My initial attempts were not particularly successful, but with a few more tips from Brock, I was able to upgrade some of my equipment and started getting some very satisfying results. Of course, the more photographs one takes, the more one learns about ways to make them better!

And those beautiful bats in the caves of Cuba?

In June 2024, my wife and I had a chance to join a bat photography workshop in Cuba with Merlin Tuttle. The highlights of that trip were two visits to Caverna Santa Catalina, an extensive cave network that extends underground for many kilometres just north of Matanzas. Over four million bats of 11 species, roost deep inside the cave, but we just had to wait near one of the many entrances to see them.

When I asked our guides where the bats would fly, the response was, “everywhere!” Not being entirely confident of that answer, I chose a spot where the cave passage narrowed to ensure I’d have lots of bats fly past my cameras. I picked some sparkling limestone as background, set my infrared trip beam pointing vertically about a metre from the cave wall, set up several flashes for lighting, then focused three cameras at different angles on the beam and waited. Soon there were tens of thousands of bats all around us, with flashes being triggered by a bat every few seconds. In two hours, my cameras had collected close to 4,000 images — it took many hours back on the computer to sort through them!

The Story Behind the Photo

One of the thousands of Antillean ghost-faced bats flying towards the entrance of Caverna Santa Catalina in Cuba.

The Story Behind the Photo

A few days later, we had a chance to return to the same cave and setup in a new spot, next to some spectacular limestone formations. One of the more intriguing photos was this Cuban fruit-eating Bat, (Brachyphilla nana) performing aerial acrobatics as it flew among the stalactites.

The Story Behind the Photo

I asked fellow workshop participant and wildlife photographer, Madelline Mathis to come and take a photo of our camera setup, suggesting she keep the shutter open until the flashes went off. There were so many bats that the flashes were actually triggered twice during this brief exposure, so each bat appears in two different places.

Where have your photographic adventures taken you recently?

One of the easiest and most rewarding photo series I took was on a recent trip to Brunei, where we noticed long-tongued nectar bats (Macroglossus minimus) feeding on Sonneratia mangrove flowers right next to an open-air restaurant and a well-lit public walkway. All I had to do was set up my camera with a few flashes, focus on a suitable flower, and then wait for the bats to appear. Every few minutes another bat would arrive, and I’d take a burst of pictures. Over the course of an hour or two, between eating dinner at the restaurant and telling passing Brunei residents about bats, I managed to get many photos of bats flying up to the flower, diving in to drink nectar, then flying away covered with pollen.

The Story Behind the Photo

A long-tongued nectar bat flying up to a mangrove flower.

Climbing in to drink the nectar . . .

. . . then flying away covered with pollen to find another flower.

The Story Behind the Photo

One of my favorite bats (although I have many favorites) is the least woolly bat (Kerivoula minuta). This tiny bat is one of the smallest bats in the world, weighing only two grams, about the weight of a dime. In flight it looks like a fluff-ball with wings; the small eyes are only visible when the bat is facing the camera. It always flies with its mouth open as it shouts out its echolocation calls, but the mouth is partly hidden by fur from the side. These bats are often looking upwards in search of potential prey — and must fly very carefully through the forest understory to avoid colliding with the many sharp thorns that could easily impale them.

Can you tell us about trip beams, flashes, and lugging equipment in Vietnam?

Setting up cameras over small ponds or quiet sections of a stream can be a great way to photograph bats, as many species of bats will fly in low to get a drink. This works particularly well in dry areas where there are only a few water sources, but even in tropical rainforest where the bats may have many places to choose from, it can be worth a try, though success is not guaranteed. One evening, at Cat Tien National Park in Vietnam, we set up my trip beam, all my flashes, and three different cameras across a very promising area of smooth water in a small stream. As the cameras were not far from the park road, we sat by the roadside in the dark to keep an eye on them and watch what happened. A few hours later, we had only seen the flashes go off a few times; two of them turned out to be leaves floating down the stream and only one proved to be a bat. Other setups have been more successful, though they’ve had their own challenges.

The Story Behind the Photo

At a small stream near Gomantong Caves in Malaysia I captured a nice photo of a fawn roundleaf bat (Hipposideros cervinus), just after a drink, with its tongue still out and water dripping from its mouth.

What is your perspective on studio photography?

Photographing bats in the wild in their natural environment is always the most rewarding, but many species of bats forage or roost in areas where it is difficult or impossible to get close enough to photograph them in flight. Also, some bats are hard to identify to species unless they are captured, measured, and examined closely. Some species can only be confirmed by examining teeth. As a result, I believe studio photography is a valuable approach for building up a library of high-quality portrait and flight photographs of the world’s bat species.

Studio shots can also provide angles or behaviors that are challenging to capture in the wild. Some of my most successful studio sessions involved collaborating with researchers who were capturing bats as part of a field survey or scientific study. For example, during a six-day session in southern Thailand, with Pipat Soisook, one of the top bat researchers in the country, we captured and photographed more than 30 species in the studio.

My studio consists of a portable tent that can be quickly and easily setup in the field, with a black cloth on one side for a background. The cameras and flashes are all aimed at an invisible infrared beam pointed vertically in the middle. When I’m ready to photograph a bat, I release it from where I’m standing, so that it flies across the beam to trigger the flashes. Of course, the bats don’t always fly in the desired direction, so I usually have to recapture them and try again a few times. Whenever possible, I photograph bats at night, soon after they are captured, and release them as soon as I’m done.

The Story Behind the Photo

A studio photograph of a Malayan hollow-faced bat (Nycteris tragata) from southern Thailand, showing off its very long ears, distinctive face pattern, and unusual long tail with a forked tip.

Come on back to the Bat Pub as we train our lens on more bat photography.

Wendy K. Probst is the editor of The Bat Pub, and a freelance editor and writer who has devoted her career to working with stellar conservation organizations like Bat Conservation International. She is both driven and anchored by her desire to dream, create, preserve, educate, and empower others.