Dolphins are very smart animals. The have the IQ as a thirteen-years-old child. There are many kind of dolphins, like common bottlenose dolphin, atlantic spotted dolphin, chilean dolphin and other kind.Dolphins sizes are vary from 1.2 m (4 ft) and 40 kg (90 lb) up to 9.5 m (30 ft) and 10 tonnes (9.8 long tons) orca.

Orca also refer as killer whale is actually a kind of dolphin. Orca’s black body with a white spot around its eye is the symbol of a orca. There are  four kinds of killer whales. Type A looks like the typical whale in movies and pictures, large, black and white with a medium-sized white eye patch. It lives in open water and mostly catches minke whale.

Type B is smaller than Type A; it has a bigger eye patch, most of the dark parts of its body are medium gray instead of black, and the white area are stained slightly yellow. It lives close to the ice pack Arctica or North Pole, which are a major area that have a huge amount of algae.For food it relays on seals also known as pinniped. Type C is the smallest kind of killer whale it lives with groups instead of separate they live around antarctica. Its eye patch is distinctively slanted forwards, rather than parallel to the body axis. Like type B, it is primarily white and medium gray, with a dark gray cape and yellow stain patches.The food source it relies on is  the Antarctic Cod, a kind of big fish that lives in deep ocean around antarctica.Type D has a extremely small white eye patch, shorter than usual dorsal fin, and round head . It lives around latitude 40 degrees and 60 degree latitude.

Killer whales are the largest extant members of the dolphin family. Males typically range from 20 to 26 ft long and weigh in excess of 6 tonnes. The largest male orca in record was 32ft. Females are smaller, generally ranging from 16 to 23 ft and weighing about 3 to 4 tonnes.The largest male killer whale on record was 32 ft, weighing over 10 tonnes , while the largest female was 28 ft, weighing 7.5 tonnes. They have significantly larger pectoral fins than females. At about 5.9 ft  the male's upper fin is more than twice the size of the female's and is more of a triangular shape—a tall, elongated isosceles triangle—which is shorter and more curved. Adult males have longer lower jaws than females, and have larger occipital crests.

Killer whales have good eyesight above and below the water, excellent hearing, and a good sense of touch. They use Echolocation Echolocation to find object in the water. Animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects and as detecting the location and characteristics of prey and other objects in their environments by emitting clicks and listening for echoes.Their main body temperature of the orca is 97 to 100 °F. Like most marine mammals, orcas have a layer of insulating blubber ranging from 3.0 to 3.9 in thick beneath its skin.

Female killer whales mature at around age 15. Pregnancy time varies from 15 to 18 months. To avoid inbreeding, males mate with females from other group. Mothers calve, with usually a single offspring, about once every five years. In resident pods, births occur at any time of year, although winter is the most common. Mortality is extremely high during the first six to seven months of life, when 37–50% of all calves die. Weaning begins at about 12 months and completes by the age of two. According to observations in several regions, all male and female killer whale group members participate in the care of the young
Females breed until age 40, meaning on average they raise five offspring. The lifespans of wild females average 50 years, with a maximum of 80–90 years. A female named Granny is the oldest known orca estimated to be 103 years old. Males sexually mature at the age of 15, but do not typically reproduce until age 21. Wild males live around 29 years on average, with a maximum of 50–60 years. One male, known as Old Tom, was reportedly spotted every winter between the 1840s and 1930 off New South Wales, Australia. This would have made him up to 90 years old. Examination of his teeth indicated he died around age 35,but this method of age determination is now believed to be inaccurate for older animals. One male known to researchers in the Pacific Northwest was estimated to have been 59 years old when he died in 2010.

Also not all killer whales are “killer whales” most of them eat fish, some of them eat big animals like seal or minke whales. They normally don’t attack people, but if people attack them or try to harm them, they will attack . Or the other situation is they are hungry and thought the boat smell like food or they misunderstand and believe that the boat as a big whale.

The humans learn a very important thing from the orca, or the dolphin. Which is  the radar. It use the same concept as the Echolocation Echolocation. The airplane or ship send out a signal, when this signal touches any solid object it bounce back, report to the airplane/ship there is something around us. The radar can help the boat evade many reef. It also help the rescue team to find missing boat from a long distance. For example like the air plane that crash a few months ago. Both  rescue airplane and ship use radar to search the signal that is from that black-box.

Source:http://animals.nationalgeographic.com/animals/mammals/killer-whale/
http://www.orcanetwork.org/Main/index.php?categories_file=Babies
http://www.orcanetwork.org/Main/index.php?categories_file=Orca%20Lifespans