fieldnotes

Tragedy and Triumph in Comoros

A fruitful search for Livingstone’s fruit bats
by Stefanie Waldek
Close-up photograph perspective of a Livingstone's fruit bat with a GPS tracker at night; The data collected by the tag provides insight into the bat's movements for up to six months.
Livingstone’s fruit bat with a GPS tracker. The data collected by the tag provides insight into the bat’s movements for up to six months.
Photo: Dr. Isabella Mandl
After spending the last decade researching endangered species on various Indian Ocean islands, Dr. Isabella Mandl knows her subjects. But on each of her recent trips to the remote islands of Comoros, the locally native Livingstone’s fruit bats have surprised her.

For weeks at a time, Dr. Mandl, Bat Conservation International (BCI) Endangered Species Interventions Research Fellow, heads to Comoros to tag the Critically Endangered Livingstone’s fruit bat (Pteropus livingstonii) with GPS trackers. Because little is known about the habits of these bats, which have a maximum wingspan of four feet, the tracking data provides crucial information about their day-to-day lives.

“For the first time, we have data on this species’ movements during the rainy season, a period with higher temperatures and lots of rain.” —Dr. Isabella Mandl
Landscape photograph perspective of Dr. Isabella Mandl (middle right) with Dhoulkifle Attoumane, Badrane Ben Ali Abdou, and Nadia Ambdi Keldi, as well as Ismaeel Janoo and Dr. Ryszard Oleksy, two colleagues from the NGO Ecosystem Restoration Alliance on Mauritius who came to support the catching efforts as they all pose for a picture together grinning outside
Catching bats requires teamwork: Dr. Isabella Mandl (middle right) with Dhoulkifle Attoumane, Badrane Ben Ali Abdou, and Nadia Ambdi Keldi, as well as Ismaeel Janoo and Dr. Ryszard Oleksy, two colleagues from the NGO Ecosystem Restoration Alliance on Mauritius who came to support the catching efforts.
Photo: Ismaeel Janoo
Dr. Mandl’s most recent foray into the field was a four-week stint at the beginning of the wet season in late September and early October, and she was eager to get to work during a period for which she had little data. But the excitement leading up to the trip turned to sorrow. Just a month before deployment, Nadia Ambdi Keldi, a team member from BCI’s local nonprofit partner, Dahari, suddenly passed away.

“Needless to say, it was difficult to get things back on track and figure out how to deal with the situation, both from an emotional and a logistical perspective,” Dr. Mandl says. But the team persevered, heading into the mountainous, forested terrain that the Livingstone’s fruit bat calls home.

A black minimalistic digital icon illustration of three short small trees situated on top of the ground
Livingstone’s fruit bats can have a wingspan of up to four feet and are notoriously difficult to catch.
On a previous Comoros trip, Dr. Mandl easily caught the bats in large nets, noting them to be relatively calm when handled. But on her last trip to Comoros, Dr. Mandl found the bats unexpectedly evasive, avoiding the nets. This time, fortunately, the bats cooperated again.

“The bats took pity on us, and we found a great spot where it was relatively easy to catch a few,” she says, acknowledging that setting up 59-foot-long nets in trees on a steep slope is, arguably, not very easy. Ultimately, the team caught seven bats, bringing the total number of tagged bats to 17.

“For the first time, we have data on individual bats’ movements during the period when it rains a lot and gets very hot,” Dr. Mandl says. “I wasn’t necessarily expecting many different things, but it turned out the bats had other plans and started becoming much more mobile and explorative.”

In May, Dr. Mandl returned to Comoros on another month-long trip, where she worked on tagging more bats. She will also experiment with techniques for gathering fecal samples and work with Dahari to identify the trees preferred by Livingstone’s fruit bats. “The GPS data helps us identify the specific trees the bats visited, ultimately leading us to find likely feeding trees,” says Dr. Mandl.

In addition to studying Livingstone’s fruit bats, Dr. Mandl and BCI’s Endangered Species Interventions group are researching new projects across Africa. “I was fortunate enough to be able to go to Kenya and Mozambique to visit caves and habitats under immense pressure of disturbance and destruction, ultimately threatening the many bat colonies living there,” says Dr. Mandl. “We are trying to set up conservation actions with local collaborators in those countries to make sure the bats can keep their homes.”

Back to Issue