There are 28 species found in UK waters; some more common than others. With so many species of cetaceans found in Scotland it is important to know how to identify one animal from another. There are a number of features that can be used to help identify cetaceans. Some of these features may be more readily apparent than others but even with just a few features visible it is possible to identify an animal to a species.
Dorsal Fin shape, size and position
The dorsal fin is the most visible part of the animal and is sometimes all that you will see when the animal surfaces to breath. Helpfully dorsal fin shape, size and position vary between whales, dolphins and porpoises and even between individual species.
Dolphin species have a prominent dorsal fin in the middle of the back
Baleen and beaked whales have a small dorsal fin two-thirds along the back
Long finned pilot whales are unusual and have the dorsal fin towards the front of the body
The shape of the dorsal fin can also help you to identify if the animal is a whale, dolphin or porpoise. In some cases you can even identify the species from the fin shape. For example the iconic shaped fin of the Orca and the long finned pilot whale are easy to differentiate from other whale and dolphin species. Dolphin species have a very sickle shaped dorsal fin which curves backward in a crescent shape, whereas harbour porpoises have a less curved more triangular shaped fin.
If the animal lifts its head out of the water the shape of the head can help you to identify the animal. Is there a beak, is the head rounded or sloping, can you see throat groves? Baleen whales (like the Minke whale below) have torpedo shaped heads and visible throat grooves. Many dolphin species have and obvious beak such as the bottlenose dolphin but some animals like the Risso’s dolphin have no noticeable beak and a rather blunt head shape.
Other identification features to look out for:
- Animal size
- Surfacing pattern
- Blow: presence, shape, direction?
- Colouration: uniform, patterned , scarred?
- Tail flukes: lifted, colour, shape?