Cal i fornia Sea L ion

(Zalophus ca l i forn ianus)

Institute for Marine Mammal Studies

P.O. Box 207

Gulfport, MS 39502

Phone: 228.896.9182

Fax: 228.896.9183

Email: contactus@imms.org

Website: www.IMMS.org

Male sea lions reach sexual maturity at 5 years of

age. Females reach sexual maturity at 3 years.

The gestation period is approximately 11 months,

with females having only 1 pup at a time. Pups

are exposed to the mother’s vocalizations and

smell at birth, both of which play an important

role in the mother-pup relationship. A pup will

nurse from its mother for 5-6 months. Pups grow

very quickly because of the richness and high fat

content of the mother’s milk. Pups will begin to

eat fish at about 3-4 months of age and are com-

pletely weaned between 6-12 months of age.

Reproduction

The Institute for Marine Mammal Studies (IMMS)

is a non-profit organization established in 1984 for

the purposes of public education, conservation and

research of marine mammals in the wild and under

human care. Located in Gulfport, MS, IMMS has

been an active participant of the National Stranding

Network since its inception. IMMS is the premiere

organization in the Mississippi-Louisiana-Alabama

sub-region of the Gulf Coast with the capability and

expertise to care for sick and injured marine mam-

mals. Additionally, IMMS promotes public aware-

ness of marine conservation issues through its in-

volvement in the community.

Distribution

California Sea Lions live in the Central and North

Pacific coastal habitats of the North and South

American continents.

Education • Conservation • Research • Recreation

www.IMMS.org www.IMMS.org

**FUN FACTS**

** Males typically grow 7-10 feet in length and

weigh 500-700 pounds. Females typically grow

5-7 feet in length and weigh 150-250 pounds.

** The average life span of a California Sea

Lion is 15-25 years.

** Sea lions were once hunted by man for their

skin and oil.

The flippers of the sea lion are highly vascular and

have significantly less fur and insulating blubber than

the rest of the body. The flippers can be used for

warming and cooling the animals in the process of

thermoregulation. When the sea lion is too cold, it will

bask in the sun to warm itself. When the sea lion is too

warm, it will swim or float in the water with its flippers

held above the water’s surface so that heat can escape

from the surface of the flippers.

Seal or Sea Lion?

Diet Scientific Classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Pinnipedia

Family: Otariidae

Genus: Zalophus

Species: californianus

Dive Masters

www.IMMS.org www.IMMS.org www.IMMS.org

Sea lions are mammals just like us! They breathe air,

are warm-blooded, give birth to live young, nurse their

young and they have hair.

Sea lions, also known as eared seals, are often confused with true seals. There are several distinguishing character-istics that separate the two groups. FRONT FLIPPERS: Sea lions have large powerful front flippers; seals have short, weak front flippers. REAR FLIPPERS: Sea lions have a rotating hip bone that enables them to tuck their rear flippers under their body and walk around on all four flippers. Seals do not have a rotating hip bone, and therefore must crawl rather than walk on land. NAILS: Sea lions only have nails on their rear flippers. Seals have sharp powerful nails on their front flippers which enable them to dig into rock or ice when exiting the water. Seals also have nails on their rear flippers. EARS: Sea lions have external ear flaps, called pinna, that cover the ear hole. Seals do not have external ear flaps and are often called earless seals.

NECK: Sea lions have long, flexible necks. True seals have short necks with limited flexibility.

California Sea Lion Harbor Seal

Physiology

Sea lion basking in the sun

Sea lions are excellent swimmers. They use their

front flippers to propel themselves through the

water. Sea lions can hold their breath 10-15 min-

utes and can reach swimming speeds of 15-20

miles per hour. They can even dive up to 600 feet!

Sea lions have great eyesight above and below the

surface of the water. However, it can be dark in the

deep ocean. Sea lions use their sensitive whiskers,

or vibrissae, to help them find food in areas where

their vision is impaired. Each whisker can move

with the underwater currents, enabling the sea lion

to "feel" any food swimming nearby.

Food sources in the wild are inconsistent. Sea

lions are opportunistic predators of over 50

species of fishes and cephalopods including

octopus, squid, herring, northern anchovy and

opaleye. Sea lions, like most marine mam-

mals, swallow their fish whole or in chunks.

They do not chew their food.

Sea lions generally obtain all the water they

need from the fish they consume.

During breeding season, male sea lions will

fast up to 3 weeks to defend their territory.

Leaving to search for food would necessitate

re-establishing territorial boundaries and

would result in a loss of mating opportunities.

Sea lion rookery

Sea lions generally eat between

10-30 pounds of fish each day.