Galápagos Sea Lions

Endemic to the Galápagos Islands and Isla de la Plata, Galápagos sea lions are a familiar sight when exploring Ecuador’s spectacular archipelago. Very social and playful by nature, these marine mammals enjoy lazing in the sun or on rocky outcrops, as well as swimming swiftly and gracefully through the surf. As they are not afraid to make their presence known with their loud barking sounds, they have been described as the informal welcoming committee for visitors to the Galápagos.

When the species was first described in 1953 it was thought to be a subspecies of the Californian sea lion (Zalophus californianus), however more recent genetic data confirms that it is a separate species (Zalophus wollebaeki) but closely related. Males of the species are on average larger than females, with well-developed necks, chests and shoulders and slim waists. Females tend to have slender necks and thick torsos. Mature males develop a bump-like protrusion on their foreheads, while juvenile males and females have a nearly flat head. Both sexes have pointy noises with prominent whiskers. Sea lions have external ear flaps, a feature that seals do not have and therefore a distinguishing feature to tell the difference between these sea mammals that are often mistaken for one another.

Their flippers are covered in black leathery skin, with short fur covering the area from the wrist to the middle of surface of the dorsal fin. Although Galápagos sea lions appear very clumsy on land, they are exceptionally agile in water. Their flippers propel their streamlined bodies through the water with ease, as they use individual flippers to steer direction. They feed primarily on sardines and are known to travel up to 15 kilometers to hunt for prey. At this time they are vulnerable to attack by sharks and killer whales.

Sea lions live in colonies, with dominant males having a harem of up to twenty-five females, and non-dominant males forming bachelor groups away from the harem. Males are constantly challenged by other males and need to keep asserting their dominance and protecting their territory. When challenged, the two contestants stretch up their necks and bark loudly as a scare tactic. If this fails to deter the opponent, they begin pushing and biting each other. Their thick, muscular necks protect their vital organs, but nonetheless blood is often drawn and males can be seen bearing the battle scars of these confrontations.

With breeding taking place over a prolonged period, there are always dependent pups in the colonies – and they are a huge attraction for visitors to the Galápagos Islands. Certainly, watching these sea lion pups playing, napping and feeding is a treat. The downside of the sociable nature of sea lions is that they are attracted to humans and this can be to their detriment as they become entangled in fishing nets, hooks and litter. So, when visiting the home of these fascinating marine mammals be sure to respect their space.

Picture attribution: Vince Smith