Making waves – a wacky new way to whale watch


Lourens Leeuwner, EWT, Wildlife and Energy Programme Manager, 

In 2017, after recognising the exciting applications of drone technology to conservation, the Endangered Wildlife Trust (EWT) embarked on a three-year-long process to obtain a license from the South African Civil Aviation Authority (SACAA) to commercially operate Remotely Piloted Aircraft Systems (RPAS). After receiving our licence in early 2020, our initial focus was limited to providing a safer and more affordable means to attach bird flight diverters to power lines than from a helicopter, but in June 2021, Eskom provided a challenging opportunity to employ our drone technology and capabilities to count waterbuck at the Kriel Power Station in Mpumalanga. We used a thermal sensor attached to the drone to look for the heat signatures of the animals at night. The sensor worked well, and after a long search, we eventually found the animals resting in dense Eucalyptus stands that would have been difficult to survey from the ground. We have since been getting requests to work with other conservation organisations and academic institutions to assist with various conservation operations – from vegetation surveys to game counts and even monitoring a hippo on the loose in Johannesburg.

In a game-changer for marine conservation research, the EWT recently partnered with the University of Pretoria’s Mammal Research Institute (MRI) Whale Unit to use drone technology to conduct critical research on the body conditions and behaviour patterns of Southern Right Whales (Eubalaena australis). We are using specialised drone technology and customised processes to observe and assess Southern Right Whales in a cost-effective, non-invasive manner to help protect this species and assess the impacts of a changing climate on sensitive marine ecosystems.


“We are really excited to assist the Whale Unit with this important work by providing a licensed drone pilot, ensuring all work can be conducted in accordance with permit conditions.  This research is a perfect example of why the EWT started the Drone project:  to support conservation work across the country through affordable aerial solutions.”

 Lourens Leeuwner, Endangered Wildlife Trust

The body condition and calving rates of these majestic animals are important factors when assessing the potential threat of global warming to the Southern Right Whale population. Their main food source is krill (a small shrimplike planktonic crustacean), and current research indicates that changes in ocean temperatures affect the abundance and location of these and other creatures, with far-reaching environmental consequences.

In this study, the Whale Unit uses photographs to assess the temporal change in the body condition of South Africa’s Southern Right Whales. These images are a mixture of aerial photographs collected in South Africa in 1988 and 1989 using a helicopter and, more recently, photographs collected using a drone. Drone images from South Africa are also applied in a comparative study with images of Southern Right Whales captured in Australia and Argentina.

Drone technology has revolutionised the way we conduct our research. Using drones, we can gather overhead images of right whales every year, allowing us to track the variation in their body condition over time in a very cost-effective manner, and collect additional photo-identification data, which allows us to assess the residency time of individual animals on the South African breeding ground. Also, an aerial view of these animals reveals more information on their behaviour than viewing them from a boat. It is truly a unique piece of technology that can be adjusted for various research projects, and we aim to apply it in much more of our research going forward.”

Dr Els Vemeulen, Research Manager of the MRI Whale Unit

After data filtering, the selected images are used for photogrammetry purposes. Using a custom-written script, measurements of the total body length and width are made (in pixels) at 5% increments perpendicular to the body axis for each whale. Subsequently, using the altitude data from the drone, these measurements in pixels can be converted to true measurements in meters. Researchers can now calculate the Body Condition Index (BCI) using the established height-width ratio of a Southern Right Whale. A positive BCI means that an animal is in better condition than the average of the sample population and a negative BCI indicate that the animal is in poorer than average condition. Clear images of the head are also used to identify animals, enabling the long-term tracking of several individual whales.

The MRI Whale Unit will be presenting the findings of their research at the 2nd Drone users conference: Conservation & Agriculture, co-hosted by the Western Cape Department of Agriculture, the EWT, and the United Nations Development Project), which can be attended virtually or in person from Monday, 29 November 2021 to Wednesday, 1 December 2021 in Elsenburg, Stellenbosch, Western Cape.  For more details, go to

You can support the MRI whale unit research by adopting a whale at

As a registered RPAS operator, the EWT is committed to the legal, safe, and responsible use of drones while promoting the use of this technology in the conservation sector.  We have an RPAS management team, including a safety manager, quality manager, and flight operations manager.