24. April 2019
Cetaceans are very special animals and during our tours we try to explain as much as possible about them in the time we have. Of course there's always something left to say!
Let's share some of these curiosities:
1. There are 92 different cetaceans species, being distributed throughout the world's oceans and many of its rivers. Some are exclusively marine, some exclusively freshwater animals and some manage to live in both environments.
2. They are "warm-blooded" animals, producing heat. Their body temperature is similar to ours (~ 37 ° C), even for those who live in cold waters.
3. They are mammals like us, which means they breathe through lungs, they give birth as we do and some species are even born with hair!
4. The Blue Whale (Balaenoptera musculus) is the largest animal that ever existed on the planet, measuring more than 30 m in length and 180 t in weight. There is the idea that some dinosaurs would be larger than the blue whale, but this is not true. If hypothetically there had been dinosaurs larger than the blue whale, they would not be able to move on land because of the gravity, they would be crushed under their own weight. Water is what allows the blue whale to move freely.
5. Cetaceans have a very special way of sleeping: as they have to stay close to the surface to breathe, they can not sleep like us. So they "sleep" resting half the brain at a time. While one half is awake to ensure that the cetacean breathes and is alert to any danger, the other half sleeps. This is why one hears that "dolphins sleep with one eye open and one eye closed."
6. They have an excellent hearing, since the sound propagates better in the water than light. For example, toothed whales (which include dolphins and porpoises) use echolocation to find food, which involves emitting sounds to determine the distance, size, shape, and texture of an object.
7. They are animals that live a long time, and there are records of whales over 200 years old, like the Bowhead whale (Balaena mysticetus).
8. Cetaceans give birth to only one calf per pregnancy, there are no records of twins.
9. Although in Portugal, whales have not been hunted for over 30 years, the truth is that there are several places in the world where they are still hunted. Despite this, that is not the major cause of death of these animals. Pollution, ship strikes, "ghosting nets" and by-catch have a major impact on cetacean populations.
10. Of the 92 species of cetaceans, 15 are baleen whales, that filtrate the water, and 77 are toothed whales, that are hunters. This last group includes sperm whales, dolphins, beaked whales and porpoises.