Established in 1985 by the late Prof. Peter B. Best, the Mammal Research Institute Whale Unit of the University of Pretoria researches the ecology, population dynamics and behaviour of cetaceans (whales, dolphins and porpoises) in Southern African waters, with the principal objective of providing information that will promote their conservation.
Our flagship project relates to the population monitoring of southern right whales which breed along the southern Cape coast.
Our most important field activity is the annual southern right whale aerial survey. This survey is conducted each year in October during which all female southern right whales with calves between Nature’s Valley and Muizenberg are counted and photographed. These surveys have been conducted since 1979, leading to an uninterrupted data series of nearly 40 years, or one of the longest running datasets of any marine mammal in the world!
Using the photographs of the whale´s unique callosity pattern, we are able to identify each individual female, allowing us to follow them over time. Through this method called “photo-identification”, we are able to derive the main population parameters, such as age of first calving, calving interval (how often the same female has a calf), calf survival rates, number of calving females, total population size and population trend over time.
Based on these surveys, it was estimated that the South African population of southern right whales contains 6,116 individuals and is currently increasing at a rate of 6.5% per year.
Since 1979, these surveys are being conducted using helicopters due to their hovering capabilities. However, we are exploring options to conduct these surveys using drones in the near future.
Identifying a southern right whale
Southern right whales are individually identifiable through the callosity pattern on their heads. These patterns are unique and stable for life. Additionally, distinct dorsal colouration patterns can aid in the identification of individuals.
Using an identification software, the callosity pattern of an individual whale can be extracted on the computer, and automatically matched against previously identified southern right whales, collated in the national South African catalogue.
As the callosity pattern of calves are not yet fully formed, calves can only be identified from birth if they have a distinct dorsal colouration pattern.