Dolphins are marine mammals that are related to porpoises and whales. They are beautiful, intelligent and highly social animals and, like humans, they can communicate with one another, are playful and curious. Many animal researchers agree that dolphins are among the smartest animals and are capable of using tools and practicing learned behavior—something that was once thought only humans and some apes could do.
There are nearly 40 species of dolphins and they range in size and weight from 4 feet (90 pounds) to 30 feet (10 tons). Despite their generally gentle nature, dolphins are carnivores and their diets consist mostly of squid and fish. They can be found in oceans worldwide, making them an animal that has appeared in art and folk legends globally. Furthermore, humans adore the dolphin due to its generally cute appearance and “smiling” mouth-line. Dolphins have been observed jumping over waves and many animal behaviorists firmly believe this is a playful action that dolphins perform simply for the purposes of fun—a concept that is largely only attributed to humans.
Dolphins are excellent swimmers due to their body shapes. The tail fin of a dolphin is known as a “fluke” while the two side fins (that somewhat resemble arms) are called “pectoral fins.” The defining fin on top of dolphins back is called a “dorsal fin” and all of these fins work together to make the dolphin more agile in the water. All dolphins breathe through a blowhole on the top of their head. Most dolphins have a two-toned gray coloring; dark on top and light on bottom. Most dolphins have excellent eyesight and their hearing is incredible—it is said that dolphins can hear frequencies ten times more than humans can. Some species of dolphins have 250 teeth that double as “natural antennas” to receive incoming sound to help dolphins pinpoint the location of objects while under the water. Dolphins also have a good sense of taste and prefer certain kinds of fish over others. Interestingly, despite having many well established senses, dolphins are believed to lack the ability to smell. Dolphins are hairless and they are sleek to the touch. They also have an acute sense of touch due to their skin that is packed with nerve endings and this might help to explain why they seemingly enjoy being touched (or outright “petted”) by humans.
Dolphins have incredible healing capabilities, although the reason for this is not well known. They have been known to recover from serious injuries like being hit by boats or bitten by sharks. Even deep wounds do not cause dolphins to hemorrhage, they are not susceptible to infections, and they heal at a rapid pace compared to human beings. However dolphins are not infallible. The U.S National Marine Mammal Foundation discovered that dolphins can develop type 2 diabetes; yet another similarity with humans.
Dolphins are highly social and live in groups, known as “pods,” that range in member size from half a dozen to over 1,000. Dolphins can form close bonds and they will stay will ill or injured individuals until they either recover or succumb. Dolphins have an elaborate language of communication that consists of vocalizations that sound like whistles and clicks. Dolphins have even been known to come to the aid of other species. For example, in New Zealand a dolphin named Moko has been seen helping a Pygmy Sperm Whale and her calf escape from shallow waters where they were in danger of getting stranded. Dolphins have also long been considered protectors of humans. They have been observed protecting swimmers from sharks by swimming in circles around the humans until the sharks back away. Furthermore, some cruises offer “swim with the dolphins” tours since some ocean locations are known as hotspots for dolphins approaching and interacting with humans.
Although dolphins are usually considered friendly creatures, they do occasionally fight among each other. Males will bite other males in competition over females. Although these fights are usually not fatal, they do leave lasting scars and the loser of the fight sometimes goes into exile as a result. The gestation period for female dolphins varies by species. The shortest gestation periods are around 11-12 months and the longest is around 17 months. Typically, all species of dolphin give birth to only one calf at a time (although twins are not unheard of) and the baby remains with its mother for milk and protection for approximately 18 to 20 months after birth.
Dolphins have a few natural enemies such as sharks and orcas (“killer whales”). Ironically it is human beings, who have much in common with dolphins and with whom dolphins can have fun and friendly encounters, that are dolphin’s biggest threat. Dolphins are hunted for food, killed by human fishing nets (often unintentionally), and fall ill due to toxins that have been released into the water by human pollution. Under water construction has also been a source of dismay for many dolphins. Luckily, human beings are as capable of kindness and they are cruelty so many “Save the Dolphin” organizations have been established to preserve these delightful creatures. OceanConservation.org, SaveJapanDolphins.org, and Bluevoice.org are just three of the many organizations that seek to protect dolphins.
Although dolphins look very different from humans, our species have much in common. By learning more about these incredible creatures we learn to respect their similarities and also their differences.