«

»

Dec 22 2015

Print this Post

California sea lion (Zalophus Californianus) – Key characteristics – interactions with humans – communications (Video)

I filmed this video in the Sea World, Saint Diego, California, USA during December 2014.
Source: www.fishconsult.org

 Sea lion (Part one)

 

Introduction: California Sea Lion,  Zalophus Californianus  belongs to the family “Otariidae” is found along the coast of the eastern North Pacific, from southern British Columbia to western Mexico including Baja California. California sea lions breed on islands off the coasts of California and Baja California, including the Channel Islands, Guadalupe, San Benitos, and Cedros. They inhabit rocky and sandy beaches of coastal islands and mainland shorelines. They may frequent sandbars; sheltered coves; tide pools; and structures such as piers, jetties, and buoys. California sea lions live for an average of 15 to 25 years. However, they can live 30 or more years.

Key characteristics: Male California sea lions reach about 2 to 2.5 m and 200 to 400 kg while female reaches about 1.5 to 2 m and 50 to 110 kg. Their bodies are tapered at both ends giving them a sleek, fusiform shape.

Generally, adult males are chocolate brown, females and young males are tan, and pups are darker in color than the adults. As adult males age, the hair around their heads lightens to a light tan.

The foreflippers of California sea lions are large and wing-like which are modified and used in an up-and-down, wing-like motion to propel themselves through the water. The hind flippers are smaller than foreflippers and when rotated underneath they body, they support the sea lion weight and enable them to walk and stand on all four limbs.

The California sea lion has visible external ear flaps on either side of its head. Adult male California sea lions have a raised forehead while females have a lower, smoother forehead.

Like all mammals, California sea lions have short stiff hair covering their bodies. They shed their hair once each year. This molt usually occurs after the breeding season.

Interactions with humans: Sea Lions are considered to be highly intelligent animals. Some species of sea lions are readily trainable and are often a popular attraction at zoos and aquariums. Far important, sea lions have been trained by the U.S. Navy Marine Mammal Program, to help the Navy in water needs especially training them to detain scuba divers.

It is very unusual for sea lions to attack humans and the reported incidences of such attacks or biting has been suggested as territorial acts.

The Moche people of ancient Peru who worshipped the sea and its animals, often depicted sea lions in their art.

Communications: It is believed that Sea Lions are among the most social animals in the world. They are very active when it comes to communication having plenty of ways to send and receive messages to and from each other.

California sea lions are among the most vocal of all animals, through vocalization they produce sounds include barks, growls, and grunts whether above and below water. Roaring is a way that sea lions use to protect their territory when they feel threatened and to keep humans and other animals away. The sea lions also bark and often use do that to interact with each other. Male sea lions barking is when they are looking for and attracting females before mating occurs. Females use a specific vocalization during the mother-pup recognition sequence.

In regard to hearing, sea Lions are believed to have excellent hearing both on land and in the water being the most important senses especially in water where hearing is probably acute. For example, the pups are able to identify the calls and sounds on their mother’s instinctively. It is believed that from birth they are able to memorize what their mother sounds like.

California sea lions have are very sensitive eyes with rounded lenses that allow their eyes to focus on light that is refracted upon entering water. They enjoy the light-gathering ability of the rod cells. In the water, their eyes adapt easily to decreasing light levels while on lad, their visual acuity is the dramatically decreased.

The smell is important to sea lions especially on land, in particular in female-pup recognition and male recognition of estrous females. Sea lions may be able to detect a human by smell from hundreds of meters away.

The sea lions use their sensitive vibrissae to explore objects on land and in the water. They seek out physical touch with other sea lions and form groups and lye with each other on land.

Permanent link to this article: http://fishconsult.org/?p=13053