An international team of scientists has used the signature whistles of individual bottle nose dolphins off the coast of Namibia to estimate the size of the population and track their movement.

The research, led by Stellenbosch University and the University of Plymouth, marks the first time that acoustic monitoring has been used in place of photographs to generate abundance estimates of dolphin populations.

They are now working to refine the technique, in the hope it can be used to track other species – with a current focus on endangered species such as humpback dolphins.

Listen here to a dolphin whistle:

You can read more about the research .

Images: Dr Tess Gridley, Dr Simon Elwin
Video: The Namibia Dolphin Project