Scholarly Article - Self-Control in Sea Lions

In 2005, a study was conducted to analyze self-control in sea lions and compare their results to that of primates. Four sea lions were tested on a reverse-reward contingency task. Each was presented with a choice between two amounts of food (fish), one which was larger than the other. They then received the opposite amount from the one they chose. Every sea lion chose the larger amount on the first trial, but three of the four were able to learn to choose the smaller amount with consistency.

A sea lion stands before the testing apparatus, anxiously awaiting his dinner.

Although primates are amoung the most social of animals, their self-control measured lower in tests than did that of sea lions

Similar studies have been conducted on sevearl species of primates, including, Japanes macaques, squirrel monkeys, lemurs, chimpanzees, tamarins and orangutans, and this study sought to examine self-control in a non-primate species. The study states, "Marine mammals are of special interest because their brain is broadly comparable to that of primates (Jerison 1973) and their learning skills have often been exploited in animal shows and military experiments." In addition, few cognitive studies have ever been conducted on sea lions, or similar marine species. It turns out that the sea lions were able to learn to choose the lesser amount more quickly than any primate, performing most similarly to the orangutans, which performed the best out of the primates. It is believed that primate self-control is realated to their social structure and hierachy, in which lower ranking individuals may have to wait their turn. Sea lions have a harem type of social organization, but theyhunt alone during the day and thus do not have to compete directly with conspecifics for fish; therefore they do not need to be impulsive. This could explain their stellar performance in self-control.

Eight Enticing Eating Habits of California Sea Lions

California sea lions are an intriguing and well-known aquatic animal that most individuals have been exposed to.

However, here we reveal eight eating habits of California sea lions that most individuals wouldn't expect:

1.  California sea lions get all of their food from the sea!

Rather than obtaining food when roaming the shores, California sea lions choose from over 50 species of fish to feed on, including hake, anchovy, and herring.

2.  Sea Lions eat about 5% to 8% of their body weight each day, which for most sea lion is over 15 pounds of food!

3.  Sea lions use their sensitive whiskers called vibrissae to explore and locate food.

4.  Sea lions do not chew their food at all.  They either tear it into chunks or just swallow it whole!

5.  Sea lions do not drink water as a source of hydration.  Instead they obtain all the water they need from their food consumption!

6.   Male sea lions will fast for weeks at a time!

During breeding season, males are required to maintain a territory in which they can attract a mate.  If they were to leave their territory and try to get food, it would allow another sea lion to potentially take their territory and their mate.

7. Sea lions feed from the top of the ocean to depths of 80 feet!

8.  Sea lions have been found to swallow stones over the span of their lives.  During the autopsy of one particularly large sea lion, 60 pounds worth of stones were found in its stomach.  Scientists have discovered no evolutionary or practical reasons to describe this behavior.

Sources:


Multiple Authors. California sea lion eating habits. Retrieved from http://www.seaworld.org/animal- 
           info/info-books/california-sea-lion/diet.htm

Territorial Behavior

California sea lions do not have a stable social organization during the non-breeding seasons. Territorial behavior in sea lions seems to be strongly correlated to their mating behavior. When the breeding season begins, males establish breeding territories with the use of barking, chest-to-chest pushing, grappling, stares, bluff lunges, and biting. Once a male sea lion has established his territory he will defend it with different boundary displays. Males will often open their mouths and shake their heads from side to side to warn other males who may be trying to intrude. Size is a key factor when it comes to winning fights and defending established territory. The bigger the male, the more blubber he can store and the longer he can go without returning to the water for food. The male’s increase their chances of breeding when they have an established territory so the longer they stay on the rocks the better their chances are of reproducing. A male sea lion can only hold his territory for up to 29 days. The sea lions territories only exist when females are present. The females pay no attention to the male’s territories and move freely between them. Sea lions are highly social and usually only become aggressive during their mating season. California sea lions normally peacefully coexist with other marine mammals during the non- breeding seasons. When in the water sea lions often travel in small groups and when on land they often aggregate in protected areas near the shore. 

Young, J., & Gerber, L. (2008). The influence of social composition on reproductive behavior of territorial male California sea lions. Aquatic Mammals, 34(1), 102-108.

http://en.wikipedia.org/wiki/California_sea_lion
http://www.seaotter-sealion.org/stellersealion/factsssl.html