What the South American sea lion is

The South American sea lion — Otaria flavescens — is a large pinniped of the eared seal family. In Spanish it's called lobo marino de un pelo. In the Beagle Channel it's the most visible marine mammal: dark-brown bulky silhouettes on rocky islets are visible from any boat leaving the port of Ushuaia.

The name "sea lion" comes from the males: an adult male grows a thick mane on the neck and shoulders.

Size and appearance

Sexual dimorphism is very pronounced:

  • Males: up to 2.7 meters long, up to 350 kg. Massive head, powerful neck, pronounced mane, dark-brown, sometimes almost black coloring.
  • Females: about 2 meters long, 140–160 kg. Color lighter — yellowish-brown.
  • Pups: born about 80 cm long and 10–15 kg, dark grey, almost black.

Where sea lions live in the Beagle Channel

  • Isla de los Lobos — "Sea lion island," the main and most famous colony. Several hundred individuals year-round.
  • Isla de los Pájaros — "Bird island." Here sea lions cohabit with an imperial cormorant colony.
  • Several small reefs and rocks near Les Éclaireurs lighthouse.
  • Islands further east, toward Estancia Harberton and the Mackinlay strait.

Total population in Tierra del Fuego waters is estimated at about 30,000; in the Beagle Channel about 2–3 thousand at one time.

How to tell a sea lion from a southern fur seal

Feature Sea lion (Otaria flavescens) Southern fur seal (Arctocephalus australis)
Adult male size Up to 2.7 m, up to 350 kg Up to 2 m, up to 200 kg
Fur One layer, smooth, short Two-layer, dense, with thick underfur
Snout Wide, blunt Narrow, pointed, "fox-like"
Mane on males Pronounced, visible from afar Almost absent
Ears Small, pressed Longer, more visible
Behavior on haul-out Often lies "log-like" on its side Sits "upright," supported by flippers

Rule of thumb: if the silhouette is massive and the animal lies flat — almost certainly a lion. If the animal is smaller, sits vertically, and the fur looks "coat-like" — that's a fur seal.

Feeding and hunting

The South American sea lion is an opportunistic predator. In the Beagle Channel its main menu:

  • small schooling fish — southern blue whiting, jack mackerel, hake;
  • squid and octopus;
  • crustaceans;
  • occasionally — Magellanic penguins and even pups of other pinnipeds.

An adult male eats up to 20 kg of fish and squid per day, diving to depths of 60–80 meters.

Breeding and life cycle

  • November. Males arrive at haul-outs first and claim plots, sorting things out in loud clashes.
  • December. Females arrive. Each strong male gathers a harem of 5–15 females. Females give birth to pups conceived a year earlier, and a few days later mate again.
  • January. Peak activity: pups are just learning to walk, males guard harems. The loudest and most spectacular month on the islands.
  • February — March. Harems break up, pups start swimming.
  • April — October. Mixed groups remain on the haul-outs: females with grown pups, sub-adults.

Lifespan in the wild — about 20 years.

Smell and sound of the colony

The first thing tourists notice as the boat approaches Isla de los Lobos — the smell. Strong, sharp, fishy-ammonia aroma carries hundreds of meters. You get used to the smell quickly.

Soundscape: bass roar of dominant males, females' bleating, pups' thin squeals and the chorus of cormorants from the neighboring island.

Conservation and history

Globally the species has Least Concern status by IUCN. But that's a recovery: in the first half of the 20th century sea lions in Argentina were hunted for hides and oil.

In the Beagle Channel all haul-outs are inside protected marine areas. Boats and kayaks must stay at least 20–30 meters from haul-outs.

When's the best time to observe

  • Best season: mid-November through late March. In December–January you can see newborn pups and male territorial fights.
  • Shoulder (April — October): animals also present, but no pups and almost no fights.
  • Time of day: morning through midday, light softer and animals more active.

How to see sea lions from Ushuaia

  1. Classic Beagle Channel boat trip — 2.5–4 hours by boat. The base to start with.
  2. Beagle Channel kayaking — paddle trip during which you can approach small haul-outs closer and more quietly.
  3. Long expedition outings to Estancia Harberton and the Martillo Island penguin colony.

Swimming with sea lions in Tierra del Fuego isn't possible: water in the channel stays at 4–9°C year-round.

Photography: what to bring and how to shoot

  • Lens. Optimal — 200–400 mm telephoto on a full-frame camera or 100–300 mm on crop.
  • Stabilization. Shoot at shutter 1/1000 second and faster.
  • Light. Best time — morning and late afternoon.
  • Composition. Look for stories: male with female, mother with pup, two males fighting.
  • Drone. Flights over colonies prohibited.

What to bring on a sea outing

  • Wind- and water-resistant jacket
  • Hat and gloves in November and March
  • Sunglasses and SPF 50 cream
  • 8×42 binoculars
  • Dry bag or ziplock for the camera

Common tourist mistakes

  1. "Let's get closer" — the captain won't go closer than allowed, and that's right.
  2. Feeding — prohibited and dangerous.
  3. "They're sleeping, you can be loud" — noise causes panic in the colony.
  4. Confusing species.

Quick: Beagle Channel sea lions in 60 seconds

  • Species — South American sea lion Otaria flavescens.
  • Main colony — Isla de los Lobos.
  • Males up to 350 kg with mane, females up to 160 kg without.
  • Best season — November–March, peak spectacle December–January.
  • Minimum distance — 20–30 meters, by law.
  • Best way to see — Beagle Channel boat trip or kayaking.