Due to its isolated locale far from the mainland, that Galapagos Islands boast only six species of land mammals. This unique ecosystem supports two types of bat and two types of rice rats, all of which you are not likely to encounter on your journey. In contrast, the two other species— Galapagos sea lions and Galapagos fur seals—will typically appear often during your Galapagos adventure.
Click on the links below to navigate to each species.
The most common native mammal that you will see during your journey is the Galapagos sea lion, a subspecies of the Californian sea lion, which inhabits most islands. There are an estimated 50,000 individuals in the Galapagos. Territorial bulls can reach up to 550 pounds and have exhibited aggressive behavior, including chasing swimmers from the water and biting people if harassed, so do not approach them too closely. On the other hand, females and pups are extremely spirited, and will often have fun swimming with snorkelers. Typically, sea lions live to the age of 20. Females reach sexual maturity at age 5; males are capable of mating then too, but usually do not do so until they are older. Dominant males patrol and guard particularly attractive beaches, territories which may contain up to thirty females. The dominant male will have mating access to these females, but only for as long as he is able to keep other males at bay. Defending a territory is very demanding work, and males may go for days without getting much food or sleep. After several weeks putting up this front, a harem-master may become weary and susceptible to defeat causing him to lose his position to a new, well-rested male.
You will see the endemic Galapagos fur seals less frequently than the sea lions, which they resemble only superficially. Upon closer inspection, however, fur seals are quite different from sea lions. They are smaller and have a wider and shorter head shaped like a bear. A fur seal’s ears are also more prominent, and their front flippers are bigger than sea lions. Fur seals and sea lions share many similar mating and social behaviors. One main difference is that male fur seals tend to defend territory from the land, while male sea lions defend from the water.
During the 1800s, the sperm whale was hunted to the brink of extinction. The upwelling waters around the islands are perfect feeding grounds for these animals, which were hunted by the thousands as the industrial revolution demanded more oil. When humans began extracting oil from the earth, the sperm whales were spared, but the rich history of the rugged whaling industry remained in the Galapagos Islands. Due to the nature of its diving, it is rare that visitors have the opportunity for an up-close encounter with a sperm whale, but it is not uncommon to see its spout on the horizon or its giant belly rise to the surface in the distance.