Elephant seals
About:
- Elephant sealsare very large, oceangoing earless seals in the genus Mirounga.
- Both species, the northern elephant seal and the southern elephant seal were hunted to the brink of extinction for oil by the end of the 19th century, but their numbers have since recovered.
- They are the largest extant carnivorans, weighing up to 5,000 kilograms.
- The northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S., Canada and Mexico.
- Elephant seals spend up to 80% of their lives in the ocean.
- They can hold their breath for more than 100 minutes longer than any other noncetacean
Northern Elephant Seal Distribution
Southern Elephant seal Distribution
- Elephant seals are shielded from extreme cold more by their blubber than by fur.
- Their hair and outer layers of skin moltin large patches.
- The skin has to be regrown by blood vessels reaching through the blubber.
- When molting occurs, the seal is susceptible to the cold, and must rest on land, in a safe place called a “haul out”.
- Northern males and young adults haul out during June to July to molt; northern females and immature seals during April to May.
- Elephant seals have a very large volume of blood, allowing them to hold a large amount of oxygen for use when diving.
- They have large sinuses in their abdomens to hold blood and can also store oxygen in their muscles with increased myoglobin concentrations in muscle.
- In addition, they have a larger proportion of oxygen-carrying red blood cells.
- These adaptations allow elephant seals to dive to such depths and remain underwater for up to two hours.
- The IUCN lists both species of elephant seal as being of least concern, although they are still threatened by entanglement in marine debris, fishery interactions, and boat collisions.
Syllabus: Prelims
