QuestionNorthern elephant seal
How Big Is an Elephant Seal? Size of Bulls, Cows and Pups
Elephant seals are the biggest seals in the world. An adult male northern elephant seal is usually 4–5 m (13–16 ft) long and weighs about 1,500–2,300 kg (3,300–5,100 lb), while southern elephant seal bulls reach about 3,700 kg (8,200 lb). Females are far smaller, often a third of a male’s weight or less.
Contents
How big is a northern elephant seal?
The northern elephant seal of the eastern Pacific is the largest seal in the Northern Hemisphere. Its size depends above all on sex and age.
| Northern elephant seal | Typical length | Typical weight |
|---|---|---|
| Adult male (bull) | 4–5 m (13–16 ft) | 1,500–2,300 kg (3,300–5,100 lb) |
| Adult female (cow) | 2.5–3.6 m (8–12 ft) | 400–900 kg (880–2,000 lb) |
| Newborn pup | — | About 35–45 kg (75–100 lb) |
| Weaned pup, about 4 weeks old | About 1.5 m (5 ft) | About 120–180 kg (260–400 lb) |
NOAA Fisheries describes fully grown males as reaching over 4 m (13 ft) and nearly 2,000 kg (4,400 lb), and females as about 3 m (10 ft) long and up to roughly 590 kg (1,300 lb). Other sources give slightly larger maximums, partly because elephant seals gain and lose so much weight through the year.
Southern elephant seals: the giants of the family
The southern elephant seal of the sub-Antarctic is bigger still. It is the largest seal and the largest member of the order Carnivora, the group that also includes bears, big cats and dogs.
| Southern elephant seal | Typical length | Typical weight |
|---|---|---|
| Adult male (bull) | 4.6–5.8 m (15–19 ft) | 3,000–3,700 kg (6,600–8,200 lb) |
| Adult female (cow) | 2.6–3 m (8.5–10 ft) | 350–900 kg (770–2,000 lb) |
Southern bulls are typically about four to five times heavier than females, one of the largest size differences between the sexes of any mammal. Size also varies by region: seals from South Georgia in the South Atlantic average heavier and longer than those from Macquarie Island south of Australia. The longest bull on record, killed at South Georgia in 1913, measured about 6.5 m (21 ft) after its blubber had been stripped, but its weight was never recorded.
Bulls versus cows: an extreme size gap
In northern elephant seals, males typically weigh three to four times as much as females, and in the southern species the gap is wider. Bulls are not just heavier; they are longer and much bulkier at the front, with a thick neck and a shield of tough, scarred skin across the chest. Only adult males grow the famous trunk-like nose, described in Why do elephant seals have big noses?
The reason is competition. During the breeding season, bulls fight for access to groups of females, and a small number of dominant males father most of the pups. Bigger males win more of these contests, so natural selection has favored ever-larger males. Males also keep growing for longer. Females usually have their first pup at about four years old, while bulls rarely win a place among the females before they are about nine or ten.
How elephant seals gain and lose weight
Elephant seals spend much of the year at sea, feeding almost nonstop on squid and fish and building up a thick layer of blubber. They then live off that fat for weeks or months on land, where they neither eat nor drink.
- Breeding bulls stay on the beach for up to three months and can lose up to 36% of their body weight, according to NOAA Fisheries.
- Nursing mothers fast for about five weeks. Because they turn their own fat into milk for their pups, they can lose a third or more of their body weight.
- Molting seals also fast for about a month while they shed their skin and fur.
This means a bull at the start of the breeding season can be hundreds of kilograms heavier than the same animal at the end. Size records for elephant seals always depend on when the animal was weighed.
How big are elephant seal pups?
A northern elephant seal pup weighs roughly 35–45 kg (75–100 lb) at birth, about the weight of a large dog. It then nurses for about four weeks on milk that is extremely rich in fat, and by weaning it weighs around 120–180 kg (260–400 lb), roughly three to four times its birth weight.
After weaning, the pups stay on the beach for up to about three months without eating, living on their fat while they learn to swim. A few pups, nicknamed “super weaners”, grow even bigger by sneaking milk from other mothers as well as their own. Southern elephant seal pups follow a similar pattern, nursing for about three weeks before their mothers return to sea.
How do elephant seals compare with walruses and other big animals?
Elephant seals are the heaviest pinnipeds, the group that includes seals, sea lions and walruses. The walrus is third, after the two elephant seals, as explained in How big is a walrus?
| Animal | Typical adult male weight |
|---|---|
| Southern elephant seal | 3,000–3,700 kg (6,600–8,200 lb) |
| Northern elephant seal | 1,500–2,300 kg (3,300–5,100 lb) |
| Pacific walrus | 800–1,700 kg (1,800–3,700 lb) |
| Steller sea lion | 450–1,120 kg (990–2,470 lb) |
| Polar bear | 350–700 kg (770–1,540 lb) |
A southern elephant seal bull can weigh as much as two or three small cars, and more than five times as much as a male polar bear. Even so, elephant seals are dwarfed by the great whales. For the biggest creatures on land and at sea, see the largest animals in the world.
Frequently asked questions
How much does an elephant seal weigh in tons?
A typical adult male northern elephant seal weighs about 1.5–2.3 metric tons (1.7–2.5 US tons), and a southern elephant seal bull about 3–3.7 metric tons (3.3–4.1 US tons). Females of both species usually weigh well under one ton.
Which is bigger, a walrus or an elephant seal?
Elephant seals are bigger. Male walruses usually weigh about 800–1,700 kg (1,800–3,700 lb), while male northern elephant seals weigh about 1,500–2,300 kg (3,300–5,100 lb) and southern elephant seal bulls up to about 3,700 kg (8,200 lb). The walrus is the third-largest pinniped.
How big is a baby elephant seal?
A newborn northern elephant seal pup weighs roughly 35–45 kg (75–100 lb). After about four weeks of drinking very fatty milk it weighs around 120–180 kg (260–400 lb) and is about 1.5 m (5 ft) long.
Are elephant seals the biggest seals?
Yes. The southern elephant seal is the largest seal and the largest member of the order Carnivora, which also includes bears and big cats. The northern elephant seal is the second-largest seal and the largest in the Northern Hemisphere.
How long is an elephant seal?
Adult male northern elephant seals are about 4–5 m (13–16 ft) long, and southern elephant seal bulls about 4.6–5.8 m (15–19 ft). Adult females of both species are usually about 2.5–3.6 m (8–12 ft) long.
Why are male elephant seals so much bigger than females?
Males compete fiercely for access to groups of females, and bigger, stronger bulls win more fights and father more pups. Size also lets a bull survive months on the beach without eating, living off his blubber while he defends his position.
Sources and further reading
- NOAA Fisheries, "Northern Elephant Seal"
- Animal Diversity Web (University of Michigan), "Mirounga angustirostris"
- Animal Diversity Web (University of Michigan), "Mirounga leonina"
- Le Boeuf, B. J. and Laws, R. M. (eds.), Elephant Seals: Population Ecology, Behavior, and Physiology, University of California Press (1994)
Cite this page
“How Big Is an Elephant Seal? Size of Bulls, Cows and Pups.” Animal Atlas, https://animals.bigworldlist.com/questions/how-big-is-an-elephant-seal/.
