7/12/2023 0 Comments Orca whaleThis cookie is managed by Amazon Web Services and is used for load balancing. This cookie is set by the Google recaptcha service to identify bots to protect the website against malicious spam attacks. This cookie is used to detect and defend when a client attempt to replay a cookie.This cookie manages the interaction with online bots and takes the appropriate actions. This is an anti-forgery cookie used for preventing cross site request forgery attacks. This cookie is set by web application built in ASP.NET MVC Technologies. These cookies ensure basic functionalities and security features of the website, anonymously. Necessary cookies are absolutely essential for the website to function properly. They hunt specific prey and live in different parts of the world. Find out more about them. Scientists now recognise several kinds of orcas (called ecotypes). Now these groups are genetically different, in addition to their unique appearance and cultures. Having multiple prey items to choose from probably led to the niche specialisations we see today – millions of year ago, different groups started eating different things to avoid competing for the same food. Orcas in the Pacific waters off Russia are still captured and sold into captivity. The Southern Residents were extensively targeted and still struggle to recover – they have never come close to regaining their pre-capture population numbers. Historically, populations in the Pacific Northwest and North Atlantic were targeted for live captures to be sold to oceanariums like SeaWorld. In some regions – Greenland, Japan, Indonesia, and some Caribbean islands – they are still victims of whaling efforts. Increase in boat traffic can result in collisions with orcas and an increase in underwater noise pollution. They get caught in fishing nets and gear accidentally, face problems with toxic waste and pollution in the sea. Orcas worldwide face a number of threats. In orca populations, knowledge is passed down to younger individuals from their elders – what to eat and were to find it, how to catch it, who to avoid, vocalisations and calls unique to pods and family groups, and the distinct ‘accent’ of the population. When sleeping, orcas swim very slowly and steadily, close to the surface. Orcas periodically alternate which side is sleeping so that they can get the rest they need without ever losing consciousness. This type of sleep is known as unihemispheric sleep as only one brain hemisphere sleeps at a time. They only close one eye when they sleep the left eye will be closed when the right half of the brain sleeps, and vice versa. To get around this, orcas only allow one half of their brains to sleep at a time the other half stays alert enabling them to continue breathing whilst looking out for dangers in the environment. If like us, orcas went into a deep unconscious sleep, they would stop breathing and suffocate or drown. Orcas cannot sleep in this way, they have to remain conscious, even when they are sleeping! This is because their breathing is not automatic - they have to actively decide when to breath, and so they must be conscious even when sleeping. We have a breathing reflex and when we sleep or become unconscious, we continue to breath automatically. Orcas sleep in a very different way to humans. However, some orcas specialise on specific prey, and it turns out orcas are picky eaters! Once they’ve learned what their family eats, they aren’t likely to switch diets. Looking at all populations, orcas are generalist eaters, consuming fish, seals and sea lions, dolphins and porpoises, sharks and rays, large whales, cephalopods (octopods and squids), seabirds and more. If you could give orcas another name, what would you call them? What do orcas eat? We know that orcas are top predators, yes, but not the vicious ‘whale killers’ that the ancient mariners thought them to be. Orcinus translates to ‘of the kingdom of the dead,’ and orca refers to a kind of whale. Their Latin name, Orcinus orca, also reflects this observation of orcas feeding on large whales. They called orcas asesina ballenas, or ‘whale killer’ – a term that was eventually flipped around to the easier ‘killer whale’. Orcas were given the name ‘killer whale’ by ancient sailors’ observations of groups of orcas hunting and preying on larger whale species. Why are orcas called 'killer whales' when they are dolphins?ĭolphins and whales are closely related.
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