Orcas grow to be about 27-33 feet (8-10 m) long, weighing more than 8,000-12,000 pounds (3.600-5.400 kg). The male orca is larger than the female. They are the largest member of the dolphin family.
The Orca's skin is mostly black with distinctive white patches. Orcas have stocky bodies and a rounded head with a distinctive beak. They have a tall, falcate (sickle-shaped) dorsal fin and large, paddle-like flippers. The dorsal fin of the male is taller (up to 6 ft tall) and more upright than that of the female (whose dorsal fin is up to 4 ft tall).
Orcas are efficient hunters that eat a very diverse diet of fish, squid, sharks, marine mammals (including whales and seals), turtles, octopi, and birds (penguins and gulls). They have even been known to attack young blue whales and other large whales. They have 10-13 pairs of large, interlocking conical, enameled teeth distributed in BOTH the upper and lower jaws (for a total of 20 to 26 pairs, so the orca has from 40 to 52 teeth). The teeth curve inwards and backwards - this helps the orca catch its prey. Teeth average about 3 inches (7.6 cm) long and about 1 inch in diameter, but some are even longer. Members of a pod frequently cooperate in hunts. An average-sized orca will eat 551 pounds (250 kg) of food a day.
Orcas live in small pods of 6-40 whales; they are very social animals. The bonds between the close-knit members of Orca pods are strong and last for life. The members of a pod hunt together in a very sophisticated manner, attacking even very large prey and then sharing it. The pod members protect the young, the sick and the injured.
Orcas can dive to a depth of 100 feet (30 m) in order to hunt. Orcas commonly breach (swim at very fast speeds toward the surface in order to rise above the surface of the water and then fall back onto the surface, splashing and making noise). Spyhopping (poking the head out of the water to look around) and tail slapping are also common orca activities. The purpose of these activities is unknown.
Orcas are very fast swimmers. They can swim up to 30 mph (48 km) in bursts in order to catch prey.
Male orcas have a life expectancy of 50-60 years. Females have a life expectancy of 90 years.