Specialised drone technology is helping researchers at the University of Pretoria Mammal Research Institute (MRI) make waves in marine conservation research.
In an effort to conduct critical research on the body and behaviour conditions of the southern right whales, the Endangered Wildlife Trust (EWT) has partnered with the university.
When assessing the potential threat of global warming to the southern right whale population, important factors to look at are their body condition and calving rate.
Drones are used to observe and assess the southern right whales in a way that is cost-effective and also non-invasive.
Research Manager of the MRI whale unit, Dr Els Vermeulen, said drone technology has helped them gain access to overhead views of marine mammals.
“We can observe behaviour better, we can get photogrammetry images, and we can obtain photo-ID images, in the case of southern right whales at least,” she said.
She added: “By using drones, we can approach whales not only relatively cheaply, but also non-invasively as they pose no disturbance to the whales.”
Vermeulen explained that these images allow them to measure the whale and its body contours, using the pixels.
“In knowing the altitude of the whale over the drone and the focal length of the camera, we can get metric measurements of the whale,” she said.
The research manager explained this allowed them to calculate the body volume and the body condition index of a whale.
“This measures how fat or skinny a whale is. In doing this over time, it allows us to observe things like how female whales’ body condition changes while lactating,” she said.
She added: “That would help us measure the energy costs of lactation on a whale.”
Using drones, the research can be completed while still protecting the whale species. Vermeulen said that before drones existed, helicopters were used.
“Helicopters and aeroplanes are expensive, complicated and more time-consuming. Flying a drone gives access to a wider range of research and is so much easier,” she said.
“The advantage is that you can collect much more data in a cheaper and more accessible way.”
The use of drones means that each year, researchers can collect additional photo-identification data. This allows them to assess the residency time of individual animals on the South African breeding ground. Vermeulen said an aerial view can also reveal more information compared to viewing whales 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.”
Vermeulen said the applicability of drones exceeds photogrammetry and that in future, they want to attach Petri dishes onto the drones.
“This will capture samples which allow us to analyse hormones and bacterial load for diseases.”
She added: “We want to film mating behaviour and how mating groups are formed. These images also help us measure their age.”
Drone technology is a silent form of observation, allowing researchers to observe these mammals in their natural environment, without disturbing them.
Southern right whales have been extensively studied through annual photo-identification surveys in South Africa since 1979, said Vermeulen.
“This study showed that southern right whales have decreased 24% in body condition or ‘fatness’ over the past two decades, and confirms that food availability has decreased for these animals.”
“We are currently busy assessing the environmental changes that lie at the basis of this.”