Northern Elephant Seal
Latin Name: Mirounga angustirostris
How often and when do we see them
These animals are frequently sighted on our tours during the fall and winter periods, often lethargically lying around on the exposed rock beds at Race Rocks. This can, at times, be good and bad as they are so large. However, their lack of movement can make them appear to be just a large boulder.
Size & Description
These animals are named after the shape of their nose, also known as a rostrum or proboscis, which resembles that of an elephants’ trunk. These Pinnipeds are the second largest seal in the world, second to the southern elephant seal. It is a part of the Phocid or true seal family, as it has no external ear flaps and moves on land, less than gracefully, by flopping around on its belly.
Males weigh up to about 8,800 lbs (4,00kg) and can be over 20ft (6m) in length. Females, being significantly less in size, only weigh up to 1,500 lbs (600kg) and can grow to 10ft (3m) in length. Besides there relative size easily indicating their sex, another recognisable feature to distinguish between males and females is the large noise, rostrum or proboscis that only males have.
Diet & Feeding
Northern Elephant seals are incredibly deep divers and it is assumed that they do not feed in water less than 200m (800ft) deep. Their prefered prey include squid, rays, sharks and certain ratfish species.
Diving – The northern elephant seal has the deepest recorded dives in the seal family, over 1500m for over a 2 hour duration under the water! One way they are able to complete such long and deep dives is due to their amazing ability to dramatically reduce their metabolic rate below resting levels – this basically means they are spending an incredibly small amount of energy whilst diving.
Dimorphism – This marine mammal has the largest phenotypic (physical) difference between the sexes of any other in the world. The male’s well developed nose or rostrum is a clear distinction that it is a mature male. The other clear characteristic is their actual, overall size – males are up to eight times larger than the mature females! This phenotypic (physical) difference between the sexes of the same species is known as dimorphism. Elephant seals have the largest!
Threats & Conservation
In the early 20th century, elephant seals were hunted almost to extinction for their blubber, specifically for lamp oil. It is assumed that the population was reduced to around 100 Northern Elephant Seals around the 1900’s. However, today's population exceeds 100,000 seals along the North-eastern Pacific coastline. A great conservational story!