Bats can use sounds in many complex ways. They can sing and even have different dialects…
When imagining a bat, the first thoughts that come to mind involve flight and their nocturnal nature. Despite the darkness, they fly by in a blur of motion, expertly catching mosquitoes or other insects. The only flying mammal in the world, bats have been extraordinarily successful in nocturnal environments because they have one of the best navigation systems — echolocation. Bats echolocate through the mouth or nose by emitting continuous ultrasonic sound pulses that bounce off objects around them and return to their ears. Instead of relying solely on vision, they perceive surrounding environments auditorily.
A bat’s life is intricately intertwined in multiple ways by use of sounds they vocalize. Studying these sounds has helped scientists learn a lot about bats — their conservation needs and the evolution of their communication systems — which is why I conducted research on bat vocalizations and their associated social behavior.
Research on echolocation has proven to be species-specific, enabling each species to be identified by its vocalizations. Scientists have recorded bats using special ultrasonic audio-equipment, called bioacoustics recorders. Each bat species has distinctly-shaped sound waves, pitch, and frequency that differentiate it. This enables species identification. The discovery that bats have different echolocation patterns has provided valuable insight on how different ones can fly in the same area, while catching different types of prey, without disrupting each other.
Bat echolocation calls are mainly used for orientation and navigation, but there is evidence that bat echolocation calls can also carry social information, including: identification of roosting and mating sites, foraging activity, and information about sex, age and other individual characteristics. Since 1960, there has been increased research on the social lives of bats, describing complex vocalizations. These facilitate group formation and cohesion, location of resources, cooperative care of young, mating, and defense of territories – all supporting long-term group stability. The fact that bats are social animals, forming colonies comprising millions as well as having long life spans, make them a promising model for studying the evolution of communication systems. There are also multiple types of information contained in bats’ social vocalizations, under varied circumstances.
Like echolocation calls, social vocalizations are often ultrasonic and species-specific. The difference is they are used only in social contexts — mainly between individuals of the same species to carry different types of information.
For at least a few bat species, studies have revealed that males are able to produce songs to attract females and/or defend their territories. Other social vocalizations have been observed in their defense of a food patch, during aggressive or warning interactions, in mother-infant communications, and to call other bats to help in repelling a predator. Although research on social vocalizations in bats has advanced rapidly in the last 15 years, exhaustive descriptions of species-specific social vocalizations are still limited. The small number of studies, especially for African species, makes it challenging to compare communication behaviors of bats and to develop a standardized system for classifying bat vocalizations.
To help fill this gap, I conducted research aimed at assessing and describing the vocal repertoire of two different bat species in the Gorongosa National Park in Mozambique, Africa. I studied Egyptian slit-faced (Nycteris thebaica) and the Sunduval’s roundleaf (Hipposideros caffer) bats. In order to compare them, I collected sound and video recordings, both in wild colony roosts and in captivity. My research was the first to reveal eleven different types of social vocalizations for the Sunduval’s roundleaf bat. I was also able to describe four additional types of social vocalizations for the Egyptian slit-faced bat, adding to the two social calls previously reported in 1990.
Although my findings added valuable information, there is still much to be discovered. Since both species are widespread in Africa, our growing knowledge of their vocal communications is opening potentially exciting doors into possible geographical variations or dialects.
My research on these two species’ social vocalizations has potentially important implications for their conservation. For instance, the Egyptian slit–faced bat is challenging to record in the wild due to its low-intensity echolocation calls. However, my study established that its social vocalizations can be more easily recorded and identified, offering a tool for monitoring population changes. Additionally, the research highlights the importance of preserving undisturbed roosts in protected areas like Gorongosa, where large colonies still exist. This may permit additional studies that could deepen our understanding of bat communication and its evolution.
“The Voice of the Bats” a short film featuring Cesária Huó and her research on bat communications and vocalizations.
About the Author: Cesária Huó, is a Mozambican scientist with a Master’s in Conservation Biology. During her Master’s degree, she conducted research on insectivorous bat social vocalizations at Gorongosa National Park, documenting complex social acoustic behavior. She intends to expand her research to also focus on bat ecology. (One of her future projects is related to the sustainable use of bat guano — an excellent organic fertilizer for agriculture.)
Love our content? Support us by sharing it!
It was a long road to Austin, Texas. More than five years after my first introduction to Merlin Tuttle’s Bat Conservation as a teenager, I packed
On warm summer evenings, as the hum of insects fills the air, it’s common to hear someone exclaim, “We could use some bats to handle
Thanks to all the Join the Nightlife: Bats and Agriculture attendees who joined us out in the field this year! Guests got hands-on experience with
Supporter and friend of MTBC, Australian conservation and animal welfare photojournalist Doug Gimesy, had his images recognized in two categories at the recent Siena International
2024 © Merlin Tuttle’s Bat Conservation. All rights reserved.
Madelline Mathis has a degree in environmental studies from Rollins College and a passion for wildlife conservation. She is an outstanding nature photographer who has worked extensively with Merlin and other MTBC staff studying and photographing bats in Mozambique, Cuba, Costa Rica, and Texas. Following college graduation, she was employed as an environmental specialist for the Florida Department of Environmental Protection. She subsequently founded the Florida chapter of the International DarkSky Association and currently serves on the board of DarkSky Texas. She also serves on the board of Houston Wilderness and was appointed to the Austin Water Resource Community Planning Task Force.
Michael Lazari Karapetian has over twenty years of investment management experience. He has a degree in business management, is a certified NBA agent, and gained early experience as a money manager for the Bank of America where he established model portfolios for high-net-worth clients. In 2003 he founded Lazari Capital Management, Inc. and Lazari Asset Management, Inc. He is President and CIO of both and manages over a half a billion in assets. In his personal time he champions philanthropic causes. He serves on the board of Moravian College and has a strong affinity for wildlife, both funding and volunteering on behalf of endangered species.
