September 28, 2020   •  
Bottlenose dolphin

Species Identification

Identification hints
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.

Common dolphin outline

Dolphin species have a prominent dorsal fin in the middle of the back

Minke whale outline

Baleen and beaked whales have a small dorsal fin two-thirds along the back

Long-finned pilot whale outline

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.

Whale and dolphin dorsal fins

Head shape
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.

 Whale and dolphin head shapes

Other identification features to look out for:

  • Animal size
  • Surfacing pattern
  • Blow: presence, shape, direction?
  • Colouration: uniform, patterned , scarred?
  • Tail flukes: lifted, colour, shape?

Behaviours

A range of behaviours can be used to help identify animals. Whether or not an animal breaches out of the water; how many animals were in the group; could you see a cloud of vapour (blow) when the animals surfaced; did the animal lift the tail fluke as it dived?

Bottlenose dolphin breach

Bottlenose dolphins are very surface active, often seen breaching and leaping out of the water.

Harbour porpoise at surface

Harbour porpoise display a characteristic rolling motion as they move through the water and are not surface active like many dolphin species.

Bottlenose dolphin and orca tailslap

Orca and bottlenose dolphin tail slapping.

Pilot whale and orca spyhop

Long-finned pilot whale and orca spy hopping.

Choose a species

Further information

WDC Species Guide • Adopt a dolphin