http://www.ck12.org Chapter 11. Understanding Biodiversity: Animals: Mammals
Evolution
Some things that have changed in general with almost all animals is a symmetrical body, a complete digestive system,
a brain and sensory organs, tissues, organs, and organ systems, a body divided into segments, and a fluid-filled body
cavity.
Ecology
The elephant seals like to eat sharks and squid. The elephant seal is a carnivorous animal, which means they only
eat meat. The elephant seal can go an extended period of time not eating. One animal that preys on an elephant seal
is the killer whale, better know as the orca.
Anatomy and Physiology
The elephant seal males can mate at age nine, and females can at age four. The elephant seal, like all other mammals,
feed milk to their young from mammary glands. Mammals have many other characteristics that define them as
mammals, such as hair, which is a typical feature. Elephant seals have hair on their eyebrows and nose. A chain
of three tiny bones transmits sound waves across the middle ear. A strong diaphragm separates the heart and lungs
from the abdominal cavity. All mammals were born alive. All the young are carried in the mother’s womb. The
male’s nose helps attract females and helps the males keep in more moisture when they are not in the water. With
this nose, they can stay out of the water for more than three months. The females do not have the big nose, just the
male. The females have a short, stubby nose.
Behavior
Elephant seals can be very aggressive. The male elephant seal fights over the female seal because it wants to mate.
Sometimes they trample and kill the babies when they are fighting over the female elephant seal. They make each
other bleed. In the breeding season, the males defend their territories. In a year, the seals will migrate about 11,000
to 13,000 miles, making two round trips between the offshore feeding areas. The females travel to foraging areas
and feed over a wide area ranging from the Gulf of Alaska to Baja California and as far as 3,000 miles off the coast
of California to the Aleutian Islands. In May and April they go back to their southern rookeries to haul out and molt.
They go back to their foraging areas in late June and May to spend the next six to eight months feeding. They return
to their pups and breeding in January.
References
- http://www.animals.nationalgeographic.com/animals/mammals/elephantseal
- http://www.bigsurcalifornia.org/elephantseal.html
- http://www.ck12.org/biology/Animal-Evolution/lesson/Animal-Evolution/
- http://www.eol.org
- http://www.faculty.stcc.edu/AandP/AP/AP2pages/Units18to20/blood/redblood.htm
- http://www.naturebytesvideo.com
- http://www.parks.ca.gov
- Kalman, Bobbie. "What Is a Marine Mammal?" Alibris Marketplace. N.p., n.d.