Here you can read more about the most fascinating species on the planet: sperm whales! Learn more about what they look like, how they live, what they eat and why they are the most amazing whales of them all! You can also read about sperm whale migrations and what is known about their strandings.
Sperm whales (Physeter macrocephalus) are record holders. For example, they are the largest animals on the planet that have teeth. The only animals that are larger are other whales, but they all have baleens instead of teeth. Sperm whales have the biggest brain of all animals, and they produce the loudest sound ever recorded in the animal kingdom. Sperm whales are also among the deepest diving animals, although they share this title with some other whales. They can dive to depths of more than 2000 meters, into a world of complete darkness and immense pressure. Their longs collapse (in a controlled way) during their descent, in order to deal with this pressure.
Just like dolphins they use echolocation to find their prey in the darkness. The problem is that their diet consists mostly of squid (including occasionally the illusive giant squid, which can leave scars on the skin of sperm whales). Squid is mostly made of soft tissue which is difficult to distinguish from water with echolocation. That is one reason why the echolocation of sperm whales has to be very loud. In general, squid is thought to be much faster than a sperm whale, so although we know how sperm whales can find the squid (echolocation), we don't know how they actually manage to catch them. In any case, the fact that sperm whales hunt on individual prey, arguably makes them the largest predators on the planet.
Males can be up to 20 meters long, although there are some claims of sperm whales measuring up to 24 meters. Females are a lot smaller, up to 13 or 14 meters. Males can also be more than three times heavier than the females, and weigh as much as 50.000 kg!
Size is not the only difference between male and female sperm wales; females generally stay in relatively warm waters, which means that in Europe, female sperm whales are usually not found north of Portugal. The males on the other hand travel further towards the poles as they grow older. In the northeast Atlantic, sperm whales can be found as far north as 80° (around Svalbard)! In fact, one of the best places in the world to see sperm whales is off the coast of Andøya, Northern Norway (69° North), where you will only find large, adult males. Nobody knows exactly why adult males travel so far away from the females, perhaps it has something to do with food, even though the females are perfectly capable of finding food without having to travel all the way to Northern Norway. Whatever the reason, male sperm whales have to migrate over long distances in order to reproduce. It was long believed that this was an annual event, and that sperm whales would feed in the far north during the summer, and travel southwards during the winter. However, male sperm whales can be found in Northern Norway throughout the year, and some sperm whales have been seen in Northern Norway for several years, without disappearing once (at least no longer than one or two months at a time). The migration of the males is therefore still a great mystery.
The video shows what we know about sperm whale migration and sperm whale strandings in the North Sea.