Unique Acoustic-behavioural Research of Humpback Whales set to continue at BCSS

June 8, 2019 | Zoe Whittall

In September last year we had the pleasure at the Bazaruto Center for Scientific Studies (BCSS) of hosting Deep Voice, an Israeli research team studying acoustic social calls of Humpback Whales in the Bazaruto Archipelago. In celebration of World Oceans Day and in anticipation of their next visit in a few months’ time, we share their experience with us.

Text and images by Deep Voice

Last year September, an Israeli research team visited the Bazaruto Center for Scientific Studies to conduct research on Humpback Whales (Megaptera novaengliae). Led by Dr. Oz Goffman, Deep Voice, comprises a handful of individuals – Michael Faran and Michael Moshe from Tel Aviv university and Daphna Stern, a diving instructor and documentary photographer. The delegation studied the acoustic social calls of the whales and their connection to their observed distribution within the Bazaruto Archipelago.

The whale population in the area follows an annual migration route that begins in the Antarctic Ocean and ends in the Bazaruto Archipelago. The whales arrive at the archipelago at the end of August for a period of three and a half months. The archipelago is their breeding ground – a designated place where they mate, give birth to and nurse offspring. The mothers and calves stay mainly inshore, at a relatively shallow depth, whilst the male pods are located in deeper waters.

Watch this short video by Deep Voice on their research expedition at BCSS in September 2018.

We recorded vocal calls and intonations of mother-calf pairs and sometimes the escort males who accompanied them. The recordings were made using hydrophones – designated underwater microphones – with a preamplifier and recorder. Five hour’s worth of recordings were made of the signals from different pods, primarily in order to detect calls of social communications between mothers and calves. In contrast to ‘singing’ of males, which were and still are a subject of extensive and long-term studies by many researchers around the world, there is barely any research into social communications between mothers and calves. 

In addition to acoustic-behavioral research, we documented, identified and photographed thousands of images within the area of study. Individuals in the whale population were identified by photo-identification of the pattern of pigmentation on the underside of the flukes and by the profile of their dorsal fin. About 60 individuals were identified photographically, out of hundreds of whales visiting the area each year. 

We have developed a unique acoustic toolbox for data analysis that will be published to aid the entire bio-acoustical community worldwide, as an open-source code. The analysis of the recorded signals and behavior as well as photo-identification of individuals will contribute significantly to Humpback Whale conservation and future studies.

Our team photographer, Daphna Stern, is currently putting together a feature length documentary feature film of this project. The film will include footage shot in the Bazaruto Archipelago as well as interviews of the Deep Voice team together with experts from BCSS.

We had an extremely successful expedition and our stay at BCSS with Dr Lebrato and his team allowed us to conduct our research in very comfortable conditions with great facilities. Following this, we look forward to expanding our research even further this year when we return in September. For this visit, we are currently looking for a volunteer who is competent at using a filming quadcopter in high-wind conditions as well as an experienced cinematographer with a basic knowledge of sound and directing.

With our professional facilities, BCSS welcomes researchers, volunteers, students, graduates, seniors, media and visitors from any background wishing to immerse themselves into a unique experience, side by side with world leading scientists and environmentalists. You can join the BCSS Volunteer Program for a once in a lifetime opportunity to not only see creatures such as Humpback Whales, but also assist in research that actively helps in their conservation and that of marine ecosystems.

For more information on Deep Voice and their research, visit their website.