Everyone knows dolphins are those smart, amazing, and lovable mammals of the waters. You may have seen them in movies such as Flipper, Zeus and Roxanne, or Ace Ventura: Pet Detective. Those movies give you a good look at the dolphins, but they don't give much insight on their behavior, or a lot of information about dolphins in the open waters. They pretty much show dolphins in captivity or by themselves. Besides, these dolphins are not being shown as they would be in the oceans, in a pod. So, here's the REAL stuff on dolphins!
The dolphin is part of the Cetacea family, so it is a (small!) relative of the whales. It is also related to the black and white orca (otherwise known as a killer whale)! It's one of the many animals that use echolocation. For all of you people who don't know what that is, it's sending out high frequency sound waves that bounces off of anything in front of them. The sound waves bounce back to the sender and by the way they come back, the animal will know what is in front of them, how far it is from them, and how to avoid it, or how to capture and eat it. The dolphin is one who uses this method. Other creatures are sharks, bats, and whales. Dolphins have a diet that consists pretty much of one thing: fish. Fish, fish, and more fish! Can you imagine eating fish (prepared the same way: raw) every day? Dolphins have round, conelike teeth that help them chow down on fish, but they're not sharp enough for tearing the flesh of bigger prey. For that, you would need very big, sharp teeth, like sharks have.
This sleek water mammal lives in pods, which is what you call a group of dolphins. These pods live together, swim together, feed together, sleep together, and play together. The human equivalent of the dolphin pod would probably be a family. There are many benefits of living in these pods. The dolphin has only one main predator: the shark. Keeping together means that they have a greater chance of spotting the shark before it can attack. And, dolphins bunched together can drive away a shark. It's like the saying, "There's strength in numbers." When another dolphin is hurt, the pod will protect, take care of, and nurse the sick or injured dolphin back to health. Sometimes, dolphins are caught in huge fish nets spanning a narrow channel or mouth of a river or something that are cast illegally by fisherman to catch tuna or other kinds of fish. Dolphins swim close to these fish because that is their main food source, so they sometimes get caught in these nets, too. When this happens, they can't swim or get to the surface for air, so they usually drown. Thousands of dolphins are killed this way. A lot of the time, however, the dolphin's pod will help the tangled dolphin up to the surface for air. That's what a family's all about: support.
Dolphins are mammals, so they have to breathe air, not water. On top of their heads, dolphins have a blowhole used to breathe so they can get air without showing their whole heads. They often spout out water from these blowholes when they come up for air. When they go underwater again, they close these blowholes so water can't get into their system, and make them drown. Since dolphins cannot breathe water, they ARE able to drown if they do not get air in time. They are also endothermic, or warm-blooded. When I say endothermic, I mean that their body has a regulated body temperature that is based on their metabolism rate. Unlike reptiles, amphibians, birds, and fish, mammals (including dolphins) do not have a surroundings-based body temperature. Take, for example, a lizard. When it gets cold outside, their bodies become cold. When it gets hot outside, their bodies get hot. We stay the same temperature throughout these temperature changes. Oh, sure, we may FEEL cold, but our body temperature stays the same. That's what being "warm-blooded" is all about. They give birth to live babies, and baby dolphins drink their mother's milk. Dolphins are also very close relatives of the whales. They are both members of the Cetacea family, but dolphins are much sleeker and better shaped for speed in the water. They can be called small whales, though, since they are members of the same family.
Dolphins have amazing hearing. Arguably, they "are the best users and perceivers of sound in the animal kingdom." If they are able to use echolocation, which requires being able to detect any difference (no matter how slight) in very high-pitched sounds, this is no real surprise. Dolphins can even recognize different melodies from the varied changes in octave and pitch. They use a language of whistles, which includes many, many whistles of different tones and pitch. They use this language to communicate with each other. (well, duh!) Although they have very good vision in both water and air, they do not have color vision, but they can distinguish between light and dark shades. Dolphins are really amazing animals!
