Animal: Dolphin

Scientific Name: Numerous, depending on the type and species

Animal Type: Mammal

Habitats: Coastline, Ocean and Tundra

The Dolphin:

The dolphin is one of the smartest non-human animals known to exist. As a sea-faring animal, they are also unique in that they are mammals. We as humans tend to be fascinated by this creature for its intelligence, friendliness and its reputation for helping those lost at sea. Many species exist, including the well-known bottlenose dolphin and the killer whale.

Physical Characteristics:

Dolphins vary in size from 1.2 metres (4 ft) and 40 kilograms (88 lb), up to 9.5 m (30 ft) and ten tons. Dolphins have a streamlined body, adapted for fast swimming. The basic coloration patterns are shades of grey with a light underside and a distinct dark cape on the back. It is often combined with lines and patches of different hue and contrast.

The head contains the melon, a round organ used for echolocation. In many species, the jaws are elongated, forming a distinct beak; for some species like the Bottlenose, there is a curved mouth which looks like a fixed smile. Teeth can be very numerous (up to two hundred and fifty) in several species. The dolphin brain is large and has a highly structured cortex, which often is referred to in discussions about their advanced intelligence.

Most dolphins have acute eyesight, both in and out of the water, and their sense of hearing is superior to that of humans. Though they have a small ear opening on each side of their head, it is believed that hearing underwater is also if not exclusively done with the lower jaw which conducts the sound vibrations to the middle ear via a fat-filled cavity in the lower jaw bone. Hearing is also used for echolocation, which seems to be an ability all dolphins have. Their teeth are arranged in a way that works as an array or antenna to receive the incoming sound and make it easier for them to pinpoint the exact location of an object. The dolphin's sense of touch is also well-developed. However, dolphins lack an olfactory nerve and lobes and thus are believed to have no sense of smell, but they can taste and do show preferences for certain kinds of fish. Since dolphins spend most of their time below the surface normally, just tasting the water could act in a manner analogous to a sense of smell.

Dolphins are social, living in pods (also called "schools") of up to a dozen individuals. In places with a high abundance of food, pods can join temporarily, forming an aggregation called a superpod; such groupings may exceed a thousand dolphins. The individuals communicate using a variety of clicks, whistles and other vocalizations. They also use ultrasonic sounds for echolocation. Membership in pods is not rigid; interchange is common. However, they can establish strong bonds between each other. This leads to them staying with injured or ill individuals.

Food Chain:

Various methods of feeding exist, not just between species but also within a species various methods may be employed, some techniques being used by only a single dolphin population. Fish and squid are the main source of food for most dolphin species, but the False Killer Whale and the Killer Whale also feed on other marine mammals.

One feeding method employed by many species is herding, where a pod will control a school of fish while individual members take turns plowing through the school, feeding. The tightly packed school of fish is commonly known as bait ball. Corralling is a method where fish are chased to shallow water where they are more easily captured.

In South Carolina, the Atlantic Bottlenose Dolphin takes this one step further with what has become known as strand feeding, where the fish are driven onto mud banks and retrieved from there. In some places, Orcas will also come up to the beach to capture sea lions. Some species also whack fish with their fluke, stunning them and sometimes sending fish clear out of the water.

Habitat features:

Dolphins are found throughout the world's oceans. The Amazon River Dolphin and others can also be found in many rivers as well.