Baleen Whales
There are 10 species, or kinds, of baleen whale.
Some of them are the: Blue, Finback, Right, Sei, Humpback, and Grey, or Gray, whales.

Baleen whales have plates of baleen growing down from the upper jaw, in rows down each side of the mouth. Baleen is made of keratin, which is what human hair and fingernails are made of. Baleen grows continuously because the lower part wears off. The stiff outer edge is smooth and the inner edge is frayed, forming a mat which acts as a strainer during feeding.

Humpback whale feeding: see the baleen plates on the upper jaw.

Most baleen whales spend the summer feeding continuously before migrating. Whales that feed in the Antarctic travel north, and those that feed in the Arctic travel south, to warmer waters for breeding. They eat little on the journey and while they are in warm water. Blubber (a layer of fat about 30 cm thick) gained during the feeding season gives them nourishment.

Feeding
When feeding, baleen whales swim with their mouths open, taking in vast mouthfuls of water. Grooves on the outside of the throat expand, increasing the mouthful. Tiny creatures called plankton and krill are sucked in through a gap in the front baleen. The whale closes its jaws, the grooves on the outside of the throat squeeze together, forcing the water out through the baleen at the sides of the mouth, leaving the food inside on the baleen.

Blue whale: the expanding grooves on its outer throat can be seen as it takes in a huge mouthful of water containing krill

Bodies
Baleen whales have 2 blow- holes on the top of their heads. When they breathe out, a spout of air and water can be seen as the spout bursts high into the air.

Baleen whales are some of the largest animals ever. This size protects them from predators and makes it easier to keep body heat. Living in water, they do not have to support their huge weight, as an animal on land does.

Baleen whales in the northern hemisphere are usually slightly smaller than those found in the southern hemisphere. All have a similar torpedo-shaped body for efficient swimming. Most are black or grey. Some are darker on top than underneath, which is good camouflage. Some species, such as Grey (also spelt Gray) and Sei whales, have white or faintly colored markings.

Each of the two sections of the tail is called a fluke. Baleen whales use their pectoral flippers (front) to steer and, with the help of the flukes, to stop.

Some baleen whales have a fin on top of the back called a dorsal fin. Grey whales have a dorsal hump followed by a series of bumps. Dorsal fins are often scarred or marked.

Some baleen whales have huge heads about 1/4 or 1/3 of their body length.

Life Cycle
Baleen whale calves are born in warm waters, which ensures their survival until they develop a layer of blubber as insulation.

Depending on the species, females give birth about 10 to 14 months after mating with a male. Twins are extremely rare. Most females have a calf every 2-4 years.

Newborn calf size depends on species: newborn Pygmy Right whales (the smallest) are about1.5 m, and Blue whales about 7 m.

Northern Right whale and calf

Whale calves stay close to their mothers. The calf's movement is helped by the current created by its mother's swimming. Whale mothers protect their young fiercely. Calves are born with small soft baleen plates. They suckle underwater, drinking milk from teats hidden inside a slit in their mother's belly.

Whale milk has a high fat content so calves grow fast and develop blubber quickly, ready for the cold waters when the whales return to the Antarctic or Arctic.

Go here for
Toothed whales

Whale Strandings

Threats to Marine Mammals

If you use any part of this, acknowledge it in your bibliography like this:
Whales (2002). [Online], Available: www.kidcyber.com.au

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Updated October 2007