Sardine Run Animal Fact File

Every year during the winter months, hundreds of thousands of sardines migrate from the Eastern Cape coast to the southern coast of KwaZulu Natal. These cold-water fish are usually found in deeper, cooler parts of the ocean, but nutrient-rich currents draw them out of the depths. The annual sardine migration is also often referred to as the “greatest shoal on earth” and it not only attracts many avid fishermen, snorkelers and scuba divers, but also a whole host of marine predators.

The sardines’ natural predators

There are a number of predators that can be found during the sardine run. This includes various oceanic birds, mammals, sharks and other predatory fish. Here is a list of predators you can expect to see at the annual sardine run:

Sardine Run - pelagic /oceanic birds

Cape gannet

Arguably the most visible hunters during the sardine run are the Cape gannets. Known for their spectacular aerial acrobatics and dive-bomb hunting techniques, these beautiful birds can be identified by their snow-white plumage, bright yellow face and neck, blue beak, and black tail feathers. They have relatively large bodies and wings - they weigh around 2.6kg and have a wingspan of 171 – 185cm. They hunt their prey by doing spectacular vertical dives into the sardine shoals (also called sardine bait balls), catching fish as they enter the water.

What do Cape gannets eat?

Sardines, anchovies, saury (fish)

What are Cape gannets’ natural predators?

Cape fur seals, great white pelicans, kelp gulls

Indian yellow-nosed albatross

The Indian yellow-nosed albatross is another regular during the sardine run. They can identified by their black and white wings, as well as a dark patch over the eye. They are slightly larger than the Cape gannet in size but not weight, averaging 81cm in length with a wingspan of 180 – 215cm and weighing in at about 2.2kg. By locking their wings in place, they soar gracefully overhead while eyeing their prey. Once located, they glide elegantly along the water’s surface, plucking fish out of the water as they fly.

What do Indian yellow-nosed albatrosses eat?

Squid, Fish, Crustaceans

What are Indian yellow-nosed albatross’ natural predators?

Albatrosses are rarely prey for other animals due to the remoteness of their breeding and feeding grounds

Greater crested tern

The greater crested tern, also known as the swift tern, has a lighter build than most ocean birds. They have a sharp, pointed yellow beak, black legs and a bushy lustrous black crest at the back of the head. Their forehead and underbody is covered in white feathers. Their back and wings are dark grey and black. They have a wingspan of 125 – 130cm and weigh about 340g. These birds mostly feed by swiftly diving or dipping into the ocean to catch their prey. Their main source of food is cephalopods, crustaceans and insects.

What do greater crested terns eat?

Sardines, Australian anchovies, leather jackets

What are greater crested terns’ natural predators?

Threats include foxes, cats, dogs, rats and silver gulls

Seagulls

Seagulls can be found all over the world, with approximately 50 different species, 6 of which can be found in South Africa, including the kelp gull, Hartlaub's Gull, swift tern, Sandwich tern, little tern and parasitic jaeger. Large flocks of gulls are very common during the sardine run and their harpy-like cries are often heard before they are seen. Most have heavy cumbersome-looking bodies, long necks and a large wingspan, with a white body and head, dark grey to black wings and tail, and a yellow or orange bill.

What do seagulls eat?

Fish, terrestrial arthropods, insects, earthworms, rodents, eggs, carrion, reptiles etc.

What are seagulls’ natural predators?

Large birds of prey such as eagles and large predatory fish

Sardine Run – marine mammals

Various marine mammals also capitalise on the sardine run as a source of food, including common dolphins, seals and whales. Dolphins in particular take full advantage of the sardine run, as the plentiful sardines make for easy pickings. They herd the sardines into a bait ball and then dive through the shoal of fish. The common dolphin and bottlenose dolphin are two of the most commonly seen dolphin species during the run.

Larger mammals like the Bryde’s whale, humpback whale and minke whale are also present at the sardine run. These sea giants are simultaneously intimidating and breath-takingly majestic. You can expect to see these gorgeous goliaths both underwater and from the water’s surface. Be sure to have your cameras ready for breaching whales, as this sight makes for a great addition to your adventure photography collection.

Seals

The Cape fur seal (also known as the brown fur seal, South African fur seal and Australian fur seal) gets its name from its thick pelt, which is much thicker than those of other seal species. Cape fur seals have broad heads, a pointed snout, small extended ears and long whiskers which help them navigate in the water, find food and other seals, and sense predators nearby. Males are significantly larger than females, with males weighing about 200 – 300 kg and averaging at 2.3m in length, while females weigh about 120kg and are 1.2 – 1.8m in length. Seals will typically swallow their prey whole underwater if it is small enough, else they surface and consume their catch bit by bit.

What do seals eat?

Fish, eels, squid, octopus, lobster, crabs, penguins

What are seals’ natural predators?

Killer whales (orcas), polar bears, leopard seals, large sharks

Dolphins

Dolphins are abundant at the sardine run. In fact, the common dolphin is considered to be the sardines’ primary predator. Dolphins are known for their underwater agility and hunting prowess, with the pod working together as a team to hunt. They hunt by herding the sardines in a tight bait ball which makes it easier for them and the other hunters to feed on the fish, including sharks, seals, birds and whales. The common dolphin ranges between 1.9 to 2.5m in length and weighs anything between 80 to 235kg. Their bodies have an atypical colour pattern. Their backs are dark grey and their bellies are white, with light grey and yellow patterns on the sides. Sharks tend to be the biggest threat to dolphins.

What do dolphins eat?

Fish, squid, crustaceans, shrimp

What are dolphins’ natural predators?

Bull shark, dusky shark, tiger shark, great white shark

Bryde’s whale

The Bryde’s whale usually treks through the ocean alone or in pairs, but can be seen in gathering in small, loose groups in feeding areas. They can be identified by large expanding throat grooves on their underside, and the hundreds of baleen plates which they use to feed. Like most whales, they suck in large quantities of water with the baleen plates act as a filter, separating the food from the water. Thereafter, the whale expels the filtered water. The males are usually a bit smaller than females but on average, these wales grow to a length of 13 to 14 m and can weigh up to 25 metric tons.

What do Bryde’s whales eat?

Fish, shrimps, crabs, lobsters, octopus, squid, cuttlefish

What are Bryde’s whales’ natural predators?

Killer whales (orcas)

Humpback whale

The humpback whale, alongside the Bryde’s whale, is also part of the baleen whale species. They can be identified by their massive, dense bodies, large hump and long black and white tail fins - the longest fins of all cetaceans. The head and lower jaw are covered in knob-like hair follicles that they use as weapons during confrontations with killer whales. They can reach lengths of 13 to 16m and weigh up to 40 metric tons. Humpback whales are usually gentle giants and can be quite friendly and they love to interact with bottlenose dolphins. You will often see them breaching, exposing almost two-thirds of their bodies and splashing down on their backs.

What do humpback whales eat?

Fish, krill, plankton

What are humpback whales’ natural predators?

Killer whales (orcas)

Minke whale

The minke whale is the second smallest of the baleen whales, being only slightly larger than the pygmy right whale. They have about 240 to 360 baleen plates on each side of their mouths. Their skin is black, grey or purple in colour and they have a white band on their flippers. The males are shorter than females, reaching a length of 6.9m. whereas females can reach a length of 8m. Both male and female whales can reach a weight of 4 to 5 tons. This species is migratory, moving between the north and south pole between seasons. Although the minke whale is commonly hunted by humans, its global status seems to be secure.

What do minke whales eat?

Fish, krill, copepods

What are minke whales’ natural predators?

Killer Whales)

Sardine run – Salt-water sharks

Sharks are very common at the sardine run, and their presence is a major attraction. Now, you might think that interacting with them could potentially be very dangerous, but the truth is that the sharks are so preoccupied with the abundance of sardines that humans are not top of the list of food items. That said, you should always be vigilant around these predators as they are still apex predators. Always listen to your diving instructor or guide when diving during the sardine run.

There are several shark species to look out for at the sardine run including the copper shark (bronze shark), blacktip shark, dusky shark and the spinner shark.  Other predatory gamefish that can also be seen at the sardine run usually include the swordfish, geelbek, shad and garrick. Also, be prepared to see shoals of anchovies swimming your way.

Copper shark

The copper shark, also known as the bonze whaler or narrowtooth shark, is the only one of its species that is found in temperate waters rather than tropical waters. They can be identified by their slender bodies, long pointed snout, and large pectoral fins. They rarely show aggression to humans, but some non-fatal attacks have been reported by spear fishers and swimmers. They can grow up to 3.3m in length and 305kg in weight. Their upper skin ranges from bronze to olive-grey in colour with a metallic sheen at the bottom. This shark is extremely fast and sometimes hunts in groups but tends to live a solitary life.

What do copper sharks eat?

Fish, squid, octopus, jellyfish, crustaceans

What are copper sharks’ natural predators?

Killer whales (orcas)

Blacktip Shark

Blacktip sharks are fast, energetic hunters that usually travel in groups. Like the copper shark, they have streamlined bodies and a pointed snout with small eyes. The upper skin of their bodies are a grey/brownish colour, and their bellies are white. The dorsal and pectoral fins both have black markings on the tips. Their jaws have 15 tooth rows on either side. They can reach a maximum length of 2.8m and a maximum weight of 123kg. Blacktip sharks are extremely curious and will approach to divers to have a better look at what they are doing. These sharks are known to leap out of the water and rotate multiple times before re-entry.

What does blacktip shark eat?

Fish

What are blacktip sharks’ natural predators?

Larger sharks, killer whales (orcas)

Dusky shark

Dusky sharks can be found worldwide. They can be identified by the bluish, bronzy skin at the top of their bodies and a white belly. They are the largest members of the requiem shark species and can reach a length of 4.2m and a weight of 160 to 180kg. Although dusky sharks usually hunt near the bottom of the ocean floor, they love taking part in the sardine run near the water’s surface, feasting on the shoals of sardine. While their large size means they are potentially dangerous to humans, there have been no confirmed dusty shark attacks, and reports of attacks can most likely be attributed to the Galapagos shark.

What do dusky sharks eat?

Fish, rays, cephalopods, crustaceans, sea turtles

What are dusky sharks’ natural predators?

Killer whales (orcas)

Spinner shark

Spinner sharks get their name from the manner in which they hunt. They swim into a shoal of fish in a spiralling motion, snapping at fish on all sides as they swim. They are grey in colour with a bronze sheen and white belly. Like other requiem sharks, they have a pointy snout with small eyes. They can grow to a maximum of 3m in length and can weigh up to 90kg. Spinner sharks mostly feed on small fish like sardines, herring, bluefish and anchovies. Like all other requiem sharks, the spinner shark gives birth to live pups, rather than laying eggs in a pouch colloquially known as a ‘mermaid’s purse’.

What do spinner sharks eat?

Fish, stingrays, squid, octopus

What are spinner sharks’ natural predators?

Killer whales (orcas)