Photographic Identification
Some species of cetaceans have naturally occurring markings on their bodies, flukes, or dorsal fins. In 1955, David K Caldwell realised that it was possible to tell individual bottlenose dolphins apart and by the 1970s, photo ID was being used to study a number of different cetacean species.
Photographic
records of these scars, nicks, notches, or colour patterns can be used to
uniquely identify individuals and can be associated with other sightings data,
e.g. location, group size/ structure and behaviour. By tracking individuals
over time and between location, long term photo-identification studies now
provide insight into habitat use, movements and life history characteristics of
individual cetaceans.
Risso’s dolphin (Grampus griseus)
Risso’s Dolphin are frequent visitors to
Orkney waters but very little is known about their movements in the region,
whether they are simply passing through or why they visit Orkney at all.
OMMRI’s development of a photographic ID catalogue for Orkney individuals, will
enable us to work with other organisations, such as WDC, to track the movements
of identified individuals and develop useful data about a species that is so
poorly understood within the UK.
We are actively seeking photos of Risso’s
dolphin taken within Orkney to help with these efforts. Even if you think they
may not be suitable, if you have photos then please get in touch with us at
sightings@ommri.org.
Killer whale (Orcinus orca)
The Scottish Killer Whale Photo
Identification Catalogue 2021 is available online and can be downloaded here (external link)