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Killer Whale
The orca or killer whale is a toothed whale that is an efficient predator, even attacking huge young blue whales. Their only enemy is human beings. Orcas live in small, close-knit, life-long pods and have 1 blowhole. The killer whale belongs to the family of dolphins and is the biggest dolphin. It is sometimes called the "wolf of the sea" because its behavior is similar to that of wolves. 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).

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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 breathe air at the surface of the water through a blowhole located near the top of the head. Their blow is a single, low bushy cloud. Orcas are very fast swimmers. They can swim up to 30 mph (48 km) in bursts in order to catch prey. Orcas whales live in waters ranging from tropical to arctic, and both coastal and deep oceanic waters. They are found in all the world's oceans and most of the seas. Orcas sometimes enter estuaries, but don't go far from the sea.

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Orca breeding occurs mostly in the winter to early spring while near the surface and in warm waters. The gestation period is about 16-17 months and the calf is born tail first (this is normal for cetaceans) and near the surface, usually between October and March. The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 6.5-8 feet (2-2.5 m) long, weighing up to 400 pounds (180 kg). Twins are extremely rare; there is almost always one calf. The baby is nurtured with its mother's milk. The mother and calf may stay together for a year or longer. Female orcas reach maturity at 6-10 years old, and males at 12-16 years old. Male orcas have a life expectancy of 50-60 years. Females have a life expectancy of 90 years.