When you think of top ocean predators, you probably think of Sharks. That’s wrong! Ocean hegemony Video
Why are orcas called ‘killer whales’ when they are dolphins?
Dolphins and whales are closely related. Orcas were given the name ‘killer whales’ by ancient sailors’ observation of groups of Orcas hunting and preying on larger whale species. They called them orcas asesina ballenas, or ‘killer whales’ – a term that was eventually transformed into the more comprehensible ‘killer whale’. Their Latin name, Orcinus orca, also reflects this observation of great whale-eating Orcas. Orcinus means “kingdom of the dead” and orca refers to a type of whale. We know that Orcas are top predators, yes, but not as vicious ‘whale killers’ as the ancient marines assumed they were. If you could give orcs another name, what would you call them?
What do Orcas eat?
Looking at all populations, orcas are general carnivores, consuming fish, seals and sea lions, dolphins and porpoises, sharks and rays, great whales, cephalopods (octopuses and squids). , seabirds and more. However, some species of Orcas specialize in eating specific prey, and it turns out that Orcas are picky eaters! Once they know what their family eats, they won’t be able to switch diets.
How do Orcas sleep?
Orcas sleep in a very different way from humans. We have a breathing reflex and when we are asleep or unconscious, we continue to breathe automatically. Orcas cannot sleep this way, they must remain conscious, even when they are asleep! This is because their breathing is not automatic – they have to actively decide when to breathe and so they have to be awake even while sleeping. If, like us, the orcas fell into a deep, unconscious slumber, they would stop breathing and suffocate or drown.
To get around this, orcas only allow half of their brains to sleep at a time; the other half remain alert so they continue to breathe while observing hazards in the environment. They only close one eye when they sleep; The left eye will close when the right half of the brain is asleep, and vice versa. This type of sleep is called monohemispheric sleep because only one hemisphere of the brain sleeps at a time. Orcas periodically alternate which side is sleeping so they can get the rest they need without losing consciousness. When sleeping, Orcas swim very slowly and steadily, close to the surface of the water.
How do Orcas communicate?
In Orca populations, knowledge is passed on to younger individuals from their elders – what to eat and find, how to catch, who to avoid, pronunciation and individual calling of the fruit and group family, and the distinct ‘voice’ of the population.