Gray Whales

By Connor Muilenburg

Gray Whale Topics

• Physical description• Whales are mammals• Feeding• Swimming behaviors• Migration • Breeding• Predators• Population

Physical Description

• Gray whales grow to be 45-50 feet long. • Gray whales weigh about 36 tons. • The gray whale's skin is gray with white

spots and has lots of barnacles.• The gray whale has two flippers, no dorsal

fin, and small ridges along its back. • Gray whales have baleens (not teeth) and

two blow holes.

Gray Whale Diagram

Whales are Mammals

Gray whales are mammals because:

• They have hair (calves have hair on the front of their head).

• They give birth to live young.

• They have lungs to breathe air.

• They are warm blooded.

• Whale calves drink their mother’s milk.

• Gray whales are the only bottom feeding whale.  • They eat shrimp-like amphipods, crustaceans, worms, fish

and squid that live in the muddy bottoms of the North Pacific Ocean.

• They scoop up a mouthful of mud, the baleens filter out the food, then the whale spits out the mud.

• The whale will stay down for 3-5 minutes to eat. • A trail of dents in the ocean floor is left behind where the

whale hit the ground.• A single gray whale is believed to turn over 50 acres of

sediment during a season of feeding.

Feeding

Swimming Behaviors

Breeching is when a whale jumps out of the water and then splashes down.

Sounding is when a whale shows its flukes.

More Swimming Behaviors

Spouting is when a whale blows out air and water drops spray up.

Spy-hopping is when a whale comes out of the water high enough to see.

• Gray whales spend the summer and part of the fall in the Chukchi Sea to feed in the rich Arctic waters.

• Gray whales spend the winter in the warm waters near Baja, CA to calve and mate.

• The round-trip is a 12,500 mile swim.

Migration

• Gray whales breed mostly in warm waters.

• The gestation period is about 13.5 months.

• The newborn calf is about 15 feet long and weighs about one ton.

• Within 30 minutes of birth the baby whale can swim.

• Calves drink milk for 6 to 7 months.

• The mother and calf stay together for about a year.

• Females have a calf every 2 or more years.

Breeding

• Killer whales, large sharks, and humans are the gray whales' only natural predators.

• Killer whales hunt gray whales off the Pacific Northwest coast of the USA.

• There has been an increase in the number of packs of killer whales waiting for the mothers and calves to begin their northward journey. 

• Rogue or wild Orcas follow the gray whales along the migration route.

Predators

• The gray whale population went way down after 1857 because a hunter found the Baja, CA calving grounds. Whales were easy to kill in the shallow water.

• In 1925 factory boats were invented which made whaling easier.

• By 1946 gray whales were almost hunted to extinction.

Population

• In 1946 laws were made so no more whaling was allowed. The gray whale population is now over 20,000 worldwide.

American Cetacean Society (1996). American Cetacean Society Fact Sheet: Gray Whales. Online: http://www.acsonline.org/factpack/graywhl.htm

Baja Jones Adventure Travel (2001). The Gray Whale Advocate. Online: http://www.greywhale.com

Enchantedlearning.com (2001). All About Whales. Online: http://www.enchantedlearning.com/subjects/whales/species/Graywhale.shtml

No Author Listed (1998). California Gray Whale Tutorial. Online: http://www.slocs.k12.ca.us/whale/whale1.html

References

The End