Dolphins: Orcas Essay, Research Paper

Orcas

? Orcas are actually the largest members of the dolphin family.

? The name “orca” means “demon from hell” in Greek. The scientific name is Orcinus Orca

? The Orca was nick named the “Killer Whale when one was seen eating another whale. It was originally called “Whale Killer” and then was later changed to “Killer Whale”. There are no confirmed records of orcas killing a human.

? Orcas are estimated to live 50-60 years

? They are said to be capable of setting an impressive pace of 34 mph and covering 60- 100 miles of ocean in a day.

? Orcas have 48 sharp teeth, that are conical-shaped and three inches long and are known to eat low flying birds and attack whales over five times their own size. They also like squid, herring and some warm blooded mammals. They consume around 100 pounds of fish a day and their favorite food is salmon. The way that they attack their prey is to circle around them.

? The orca is black on the top half of it’s body and white on the bottom half because their dark back blends n with the darker water and the white bellies blend in with the sunlit water above them.

? Male orcas can reach up to 32 feet, weigh over eight tons and have a dorsal fin of up to five feet tall

? Females can grow up to 22 feet tall, weigh about four tons, and have a three foot dorsal fin.

? Orcas are found in all oceans of the world and favor coastal temperate or cool waters. However, they also range into polar areas. Some orca populations remain local and travel along predictable routes and others are transient and move over great distances.

? Mating and birth take place mainly in autumn and winter. Gestation lasts over 12 months and at birth orcas are about 6-7 ft long and weigh almost 400lbs. They are born tail first.

? Females may give birth to four to six young during a lifetime.

? Orcas are very social whales and most pods consist of 5-30 individuals

? Studies have shown that each pod has its own distinctive dialect or accent, and that members of the same pod can recognize each other through this distinctive dialect

? Orcas do not migrate, but have seasonal movements, which are tied into prey movement and environmental changes.

? Capture of orcas for display has become controversial and more restricted. Never before has a captured orca been returned to the ocean.

? Orcas and all whales, along with dolphins use and advanced system of SONAR, which stands for Sound Navigation Ranging. This is called Echolocation. The most frequent are loud bursts; these are used to located prey. The sound waves bounce off the object and are reflected back to the orca. These reflections are received by the jawbone and interpreted into an exact location. The high pitched whistles and shrills are used to communicate with other orcas even at a distance of several miles.