Cetaceans - Whales, Dolphins & Porpoises...
... or in short – cetaceans – are marine mammals that have adapted to a life exclusively in the water. In contrast to fish, they do not have gills, but breathe with lungs, like we do. That is also the reason why we can see them: because they have to come to the water surface to breathe. And that’s where we have our chance to have some amazing encounters. They give birth to live young and nurse them, and are warm blooded, just like land mammals. But because they spend most of their lives underwater, they can be really hard to find.
To move through and live in the marine environment, they have developed unique adaptations over millions of years. To propel themselves forward, their tails have turned into powerful flukes. And to direct their movements, their forearms have turned into pectoral fins or flippers, while their hind-legs have reduced almost completely. To make surfacing and breathing easier, their nostrils have moved to the top of their heads and are called blowholes.
25 species of cetaceans have been identified in Irish waters, many of which occur around the Iveragh peninsula. A study in 2015 concluded that common dolphins, bottlenose dolphins and minke whales are the most frequently seen cetaceans in south Kerry. If you get lucky, you might also see Risso’s dolphins, humpback whales or the much smaller harbour porpoises. Of the 28 species seen in UK waters, the Llŷn peninsula shares a few species with Iveragh: Risso’s and bottlenose dolphins, harbour porpoises and minke whales. But pilot whales can occasionally be seen also. Most cetaceans can be observed from land and from the water. However, when observing from a boat, specific guidelines must be followed to ensure the animals and passengers safety.
Mysticetes vs. Odontocetes
Two fancy (scientific) words for the two categories of cetaceans (another fancy word for whales, dolphins and porpoises). These two words describe parts of the animals anatomy and how they feed:
Mysticetes aka baleen whales
Odontocetes aka toothed whales
Surface feeding humpback whale showing throat pleats and paired blowholes – C. Winkler
Porpoising common dolphin showing a slender beak and one single blowhole - C. Winkler
Did you know...
… that cetaceans are conscious breathers? While our breathing is a reflex that we do not need to think about and literally can do in our sleep, cetaceans have to be awake to breathe. But how do they do that? One of the most common assumptions is that only one half of their brain sleeps at a time, while the other half stays awake and controls their breathing and is alert for possible danger.
How do Whales and Dolphins Breathe? - UK.whales.org
Species - IWDG
Ultimate wildlife watching adventures in Llyn – National Trust UK
What is the difference between a whale and a dolphin? - IWC
Fluke Facts - IWDG
How do whales sing? - BBC
Echolocation - IWC