Who doesn’t love these friendly creatures? But there is so much more than meets the eye when it comes to dolphins. They are a highly variable and intelligent species. Here are some interesting facts about our fishy friends.
1. There are approximately 43 species of dolphins, consisting mainly of marine dolphins
and a few river dolphin species. There are slight differences between the marine and river dolphins, mainly due to the differences in their hunting styles.
2. They usually consume a diet of fish and squid, although this varies amongst species.
3. The average dolphin reaches about 6 to 13 feet in length and can weigh up to about 100 lbs or even more.
4. Dolphins are mammals and therefore require air to breathe. They breathe through blowholes on the top of their heads and not through their mouths, as to prevent drowning while hunting and consuming food. A dolphin seals its blowhole when it goes underwater and can hold its breath for up to 7 minutes.
5. Breathing could become a potential problem while sleeping but they have managed to find a very creative solution. They only sleep with one brain hemisphere at a time, allowing the other hemisphere to keep them awake enough to breathe and watch out for potential predators. Unlike humans, they cannot breathe autonomously but need to actively remind themselves to breathe, therefore it is essential to always have one hemisphere of the brain active.
6. Dolphins in captivity do, however, sleep with both sides of their hemispheres and can breathe autonomously. These dolphins exhibit a tail kick reflex which forces them forward, and their blowholes to remain above water and prevent them from sinking while sleeping.
7. Female dolphins are referred to as cows and male dolphins are called bulls, with the babies being called calves.
8. Calves are born with their tail being expelled first, which is an uncommon phenomenon in the ocean world. As they are air-breathing, they would die if they were birthed head first.
9. It takes 17 months for gestation to be completed and a calf can nurse on his milk-producing mother for up to 2 years and remain in her care for up to 8 years. It has even been observed that dolphin mothers play and cuddle with their calves.
10. Dolphins are very social animals and communicate with each other by using clicking and whistling noises. They even develop unique whistles that they use so that other dolphins can identify them, similar to humans having names.
11. Being able to identify each other is important as dolphins travel in groups of approximately 15. These groups are referred to as pods. Some pods even combine temporarily when they inhabit the same area for a period of time and are then called Superpods.
14. While hunting they use special high-pitched clicks, called echolocation, that allows sound to bounce off of objects like fish and travel back to them as echoes. This allows them to determine the location, size, and shape of the object or prey.
15. Dolphins do not have many enemies. Some of the more dangerous shark species, like the bull or tiger sharks, do hunt dolphins, however. Some larger dolphins have been found to consume smaller dolphins, although this is a rare occurrence. The main threat to dolphins is humans. Water pollution poses a great risk to dolphins and many other ocean creatures. Overfishing is also a great concern, as many dolphins’ main food supply includes fish.