Oct21

Name that cetacean!

Categories // Survey & Sightings News

Name that cetacean!

Inspired by a great new field guide, we've got some top tips for helping you to identify cetaceans at sea! 

Identifying cetaceans at sea can be a real challenge – so how do ORCA surveyors tell different species apart?

With so many different species of cetacean there are many who can be devilishly difficult to tell apart, particularly when spotting them at sea. We’ve pulled together a list of our top tips for telling species apart so that you can tell your bottlenose dolphin from your sperm whale when you are next out at sea!

  1. All creatures great and small: Size and shape are the first clue to look at when spotting marine mammals at sea – with a blue whale over 23 times the size of a vaquita, there’s a huge range in size in the whale and dolphin world! Obviously animals seen at a distance are likely to be larger, but to get a sense of scale you can also use landmarks or even other animals (such as sea birds) to give you a more accurate estimate at size.
  2. There she blows!: A visible blow is a great clue to help distinguish a species. Blows at a distance are usually a sign of large whales, and some species can have a fairly distinctive shape. For example, sperm whale blows are at an angle as a result of their blow being on the left side of their head, whilst blue whale blows are very tall and columnar. Be warned though – sometimes wind can deceive you so always use blows along with other features to get a confirmed identification!
  3. Fin-tastic features: The size, shape and position of the dorsal fin is one of the best ways of identifying a species at sea. Whales tend to have smaller dorsal fins around two thirds of the way down their body, whilst dolphins and porpoise usually have a larger fin relative to their body size, most often found in the centre of their body. The shape, colour and even angle of the dorsal can all also be used to make a positive identification.
  4. Colour me cetacean: Colouration and patterning are also a great way of telling different species apart. From the distinctive blue of the blue whale to the iconic black and white of an orca, many species can be quickly and effectively identified by their patterning so keep your eyes peeled for those rainbow clues!
  5. Behave yourselves: Finally, keeping an eye out for distinctive behaviours is another fab clue to help make a clear identification. Some species are known for their breaching, whilst others are seen fluking, tail slapping or spy hopping. However, be careful here also – behaviour should always be used alongside other features to make a positive ID as sometimes cetaceans like to mix things up a little and behave a little unusually!

There is a lot to learn about all of the species you can encounter in Europe alone, so it’s really important to make sure you’ve done your research. ORCA worked this year on a brand new field guide with WILDGuides called “Europe’s Sea Mammals” which is the perfect companion to take with you when you go to sea. The book also includes data collected by ORCA volunteers over the past 15+ years, so it’s a great way to see our work in action.

Europes Sea Mammals front cover

So next time you are out at sea, make sure to keep your eyes peeled and hopefully you’ll be better prepared to accurately identify whales and dolphins on your travels on the waves!