The Southern Elephant Seal
The southern elephant seal, one of two species of elephant seal, belongs in the family of true seals known as pinnipeds. They are the largest of the pinnipeds. They can be found in the southern hemisphere and are named for their massive size and large noses that resemble an elephant’s trunk. Below are interesting southern elephant seal facts.
The males are much larger than the females. Males average 20 feet in length and weigh 8,800 pounds. Females average 10 feet in length and weigh 2,000 pounds. Both have strong, sturdy bodies with thick necks and broad heads, but only the males have the large, inflatable nose. Both sexes have short front flippers and strong, webbed back flippers which allows them to swim through the water with exceptional speed and agility.
Southern elephant seals spend most of their lives in the water. When they do come on land, it is to occasionally rest, molt and breed/give birth. Molting happens around January and lasts about 30 days. When breeding/giving birth, the males stay on land for about two to three months and females stay about one month. During these times, they do not eat and can lose quite a bit of weight. Males can lose up to 40 percent of their weight and females can lose up to 35 percent.
Once back in the water, these seals will spend most of their time diving for food to make up for their weight loss while on land. They can dive over 4,900 feet deep, stay underwater for up to two hours and need only a short period of time to breathe between dives. They eat mostly large fish and squid but will occasionally prey on penguins.
Females reach sexual maturity between two to four years of age. Males reach sexual maturity between three to six years of age, but they do not begin to breed until they are about 10 years of age. When the breeding season begins in August, the males come on land first to fight for breeding rights, striking each other with their trunks and teeth. This competition can be very aggressive and quite bloody. Only two to three percent of males win the breeding rights to a ‘harem’, consisting of up to 100 females.
Females give birth to one pup annually (twins are rare). At birth, pups measure about 4 feet long and weigh roughly 100 pounds. In about three weeks, when weaned from their mother’s fat-rich milk, they will weigh around 300 pounds. After the pups are weaned, the females return to the sea and the pups are left on land to fend for themselves. In about three to eight weeks, the pups will become hungry and find their way to the ocean. They learn to swim and feed on their own.
A few days before the pups are weaned, the females will mate again. Implantation is delayed for about three months and the gestation period lasts about eight months. This helps maintain the yearly birthing cycle.
The following are more interesting southern elephant seal facts:
- These seals were once hunted for their oil. One typical male could produce about 90 gallons of oil.
- Today, they are protected by the U.S. Fish and Wildlife Services. Approximately 600,000 exist.
- Known predators include large sharks. The leopard seal and killer whale are known to prey on pups.
- Females live about 23 years and males about 15 years.
Antarctic Connection: https://www.antarcticconnection.com/antarctic/wildlife/seals/s_elephant.shtml
Marine Bio: https://marinebio.org/species.asp?id=296
The Encyclopedia of Earth: https://www.eoearth.org/article/Southern_elephant_seal?topic=49540