Galapagos Costal Life - Mikey Oh

Mike Oh

Galapagos Winter Term

Photo Essay: Coastal life of the Galapagos

Galapagos fur seals are endemic to the Galapagos Islands.  They are the smallest of the eared seals, or otariids. They live on rocky cliffs by the water where shade is provided to protect them from the sun.  The picture is showing habitat of the fur seal, and a fur seal pup.  Fur seals have the longest nursing period than any other seals, and the adult fur seals leave their offspring behind for up to four days while they go hunt for food.  Their usual diet is fish or squids, and they usually hunt at night.  Reason they usually hunt at night is because their diets are easier to hunt during night; squids rise near the surface during nighttime. They live in colonies, but during mating season (mid-August to mid-November), female seals have their own territory to breed in.  In order to reproduce, females must protect their territory; therefore extremely violent to other pups that are not their own.  Large amount of pups die during the time of El Nino because of starvation.  During El Nino, fur seal population decreases by large percentage.  However, fur seal do not face constant danger of predators.  Sharks and orcas can be recognized as their predator, but it is very rare.

Galapagos penguin is endemic to the Galapagos Islands.  They are primarily seen on Fernandina and Isabela Island, but they also appear on other islands such as Bartolome Island or Santiago Island.  They are third smallest penguin, and only penguin to cross the northern hemisphere.  They feed on small fish, hunt during the day and stay on land during the night.  They don’t stay too far from their breeding sites, and mainly depend on the cold currents for their food.  Their breeding pattern is very interesting that during El Nino, they put off breeding in order to raise the chances of survival.  They usually put off breeding unless the surface temperature of the ocean is below 24°C.  Since the Galapagos is located on the equator, the strong sun becomes major problem for Galapagos penguin.  They have developed behaviors to stay cool on land, although main method is going into the water.  They hunch over to provide shadow for their feet, where they can lose heat due to the blood flow.  Also, they are able to pant to cool the throat.  Their small size resulted in having many predators, on land and under water.  Hawk, owl, and snakes attack penguins, and sea lions, fur seals, and sharks hunt penguins.  Also, El Nino destroys Galapagos penguin’s food source, resulting decrease in population. 

Red-footed boobies are the smallest of all types of boobies.  They can be differentiated from other boobies by its red foot and blue and pink beak.  They are not endemic to the Galapagos Islands, but found on many tropical islands.  They feed at sea, with their great diving skills.  They are also strong fliers that they can travel about 150km to hunt. They are well adapted for diving with their closable nostrils, long bills, and long wings to wrap the body before the diving.  Once under water, they use their feet to swim.  They nest on land around coast.  They have several morphs, such as white morph or brown morph, which describes their body color.  Red-footed boobies live longest out of 3 boobies in the Galapagos.  However, their reproduction rate is slower than Blue-footed or Nazka boobies.  Unlike other two boobies, Red-footed boobies lay their eggs on the tree.  They mate in large mass, and both parents takes care of the egg. 

Marine Iguana is endemic iguana to the Galapagos Islands, and has unique ability to be underwater.  Their ancestor is thought to be the green iguana of South America, taken by the current leading to the Galapagos Islands.  It dives about 10 m into the water, and uses its tail and body movement to swim.  Their tails are flat on the sides unlike round tail of land iguana, which helps them swim. They dive to eat marine algae or seaweed, and they shoot out excess salt from their body using special gland in their nostril.  Because of the cold seawater, they must warm their body with sun before diving.  This is why it is common to see marine iguanas sunbathing on rocks by the coast.  Their black body color also helps them absorb heat quickly, which helps them minimize the danger of losing too much heat after emerging from water.   Marine Iguanas cannot move effectively if their body heat is low.  They are very vulnerable after eating underwater, therefore becomes aggressive before warming up.  Another time Marine Iguanas are aggressive is during mating season.  Males are highly territorial while mating season, protecting group of females. 

Galapagos sea lions are descendent of California sea lions.  The current leading to the Galapagos has brought some of the California sea lions to the archipelago.  They are slightly smaller than California sea lions, and they are around 1.5m~2.5m, and weigh up to 400kg.  They live around the coast forming community with one alpha male.  Other males who lost the competition live in separate community consisted of other males without power.  They challenge alpha male, fighting for the territory.   Because of this challenge system, male sea lions develop many different traits.  Their forehead grows larger and pointier to use during the fight, and their necks get thicker and tougher to protect its vital organs.  Most dominant males don’t last over few months.  One that loses gets chased off from the community, moving in with other males.  The alpha male constantly patrols around their territory, checking both underwater and land.  The female recognizes its cub through its smell and bark.  The female can spot its cub’s bark within large number of other cubs barking.  The cow nurtures its pup up to 3 years, having a very strong bond between the mother and the cub.  Large part of their daily life is lying around the beach sunbathing in large groups.