Starving African penguins: stones found in the stomachs of rescued chicks

On 3 February 2026, CNN published a report from South Africa's south-western coast on the African penguin, the only penguin species that breeds in Africa, and on how hunger is now shaping its decline. At the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), the country's best-known seabird rescue and rehabilitation group, staff have found stones in the stomachs of seabird chicks that later died. Most of them were cormorant chicks, but stones have also been found in the stomachs of penguin chicks. "The parents were so desperate to feed the babies something that they were feeding them stones," Robyn Fraser-Knowles of SANCCOB told CNN. The report drew on a study published in December 2025 which found that about 62,000 breeding African penguins most likely starved after sardine stocks collapsed off western South Africa.

CNN opened its report on the shore at Betty's Bay where a colony of African penguins stood with their white bellies to the summer sun. Unlike their Antarctic relatives, African penguins live in a warm climate, along the temperate coasts of South Africa and Namibia, and they draw tens of thousands of tourists to southern Africa every year.

The Betty's Bay birds belong to the Stony Point colony, one of the few places where the species breeds on the mainland rather than on an offshore island. Stony Point and Boulders Beach near Simon's Town were both founded by penguins in the early 1980s, starting with one or two pairs each. Mainland colonies are thought to have become possible only as the numbers of land predators fell, and the Betty's Bay colony has still been attacked by leopards. By 2022, Lorien Pichegru of Nelson Mandela University told Mongabay, Stony Point held about 1,600 pairs and Boulders Beach about 1,000.

"We are watching these birds every day coming in (to SANCCOB) with quite severe trauma, with emaciation problems; they are struggling a lot out in the wild," Jade Sookhoo, a rehabilitation manager at SANCCOB, told CNN.

The African penguin (Spheniscus demersus) is also known as the Cape penguin and, from its loud braying call, the jackass penguin. Adults are black above and white below, with a black band across the chest shaped like an upside-down horseshoe and a scatter of black spots whose pattern is different on every bird. Bare pink skin above the eyes helps the bird shed heat: as the temperature rises, more blood flows to the glands there and they turn pinker. The dark back and pale belly are a form of camouflage known as countershading, which makes the bird harder to see from above and below in the water.

The species breeds in colonies on islands between Namibia and Algoa Bay, near Port Elizabeth in South Africa, and on a handful of mainland sites. It hunts in the open sea for small shoaling fish, chiefly sardines and anchovies, along with horse mackerel, round herring, squid and small crustaceans.

Pairs are monogamous and return to the same site each year. A clutch is usually two eggs, laid in a burrow or in a nest under boulders or bushes. Both parents share the incubation, which lasts about 40 days. At least one parent guards the chicks for about a month; after that the chicks gather in a crèche while both parents spend most of the day fishing. Chicks leave the colony at 60 to 130 days old, and when they fledge depends largely on how much food the parents can find.

The birds once dug their burrows into thick layers of guano, the droppings built up on the islands over centuries, which kept eggs and chicks cool and out of reach of predators. People stripped the guano and sold it as fertiliser, leaving many penguins to nest in the open. Penguin eggs were also collected and sold as food: 12,000 eggs were taken from Dassen Island in 1953 alone.

Millions of African penguins once lived along the coasts of South Africa and Namibia. In November 2024, BirdLife International said that fewer than 32,000 remained in the wild, about 1 per cent of the original population, that 97 per cent of the population had been lost, and that the species could vanish from the wild in fewer than 4,000 days without urgent action.

In the mid-1950s there were an estimated 141,000 breeding pairs, or 282,000 mature birds. By 2023 the count had fallen to around 9,900 pairs, or 19,800 birds, a decline of 93 per cent in about 70 years, Mongabay reported in November 2024. The International Union for Conservation of Nature (IUCN) assessment of July 2024 put the numbers at about 1,200 pairs in Namibia and 8,750 pairs in South Africa. South Africa's own count had stood at 15,187 pairs in 2018. Over the last 30 years alone the population is estimated to have fallen by 80 per cent, CNN reported.

The species had been listed as Endangered since 2010. In 2024 the IUCN moved it to Critically Endangered, the last category before Extinct in the Wild. Natalie Maskell, SANCCOB's chief executive, said in response that SANCCOB would "continue to fight for the future of this iconic species; we must remain optimistic that their trajectory can be reversed." Richard Sherley, an ecologist at the University of Exeter, said the listing "highlights a much bigger problem with the health of our environment."

Alistair McInnes, who manages BirdLife South Africa's seabird conservation programme, told BirdLife that the main problem lies out at sea, out of sight: "when people visit colonies at Stony Point or Boulders, they see the birds in large groups and don't understand the level of threat or what's affecting the penguin populations."

The study CNN cited was published online on 4 December 2025 in Ostrich: Journal of African Ornithology (volume 96, issue 4) under the title "High adult mortality of African Penguins Spheniscus demersus in South Africa after 2004 was likely caused by starvation". Its authors were Robert Crawford and Azwianewi Makhado of South Africa's Department of Forestry, Fisheries and the Environment, Richard Sherley of the University of Exeter, Lynne Shannon of the University of Cape Town, Alistair McInnes of BirdLife South Africa and Tegan Carpenter-Kling of Nelson Mandela University.

The researchers looked at two of the most important breeding islands, Dassen Island and Robben Island, off the west coast near Cape Town. In the early 2000s Dassen held about 25,000 breeding pairs and Robben about 9,000. About 95 per cent of the penguins that bred on the two islands in 2004 died over the following eight years, the paper estimated, a loss of about 62,000 breeding birds. "These declines are mirrored elsewhere," Sherley said.

The authors concluded that the birds most likely starved around their annual moult. An African penguin replaces all its feathers once a year to keep its insulation and waterproofing. The moult takes about 21 days, and because the new feathers are not yet waterproof the bird cannot go to sea and must fast on land, losing nearly half its body weight. Before the moult, adults weigh on average 31 per cent more than breeding adults, and the study notes that worn feathers slow a penguin down: about 14 km an hour against 19 km an hour in fresh plumage, and only about 10 km an hour just after the moult.

"If food is too hard to find before they moult or immediately afterwards, they will have insufficient reserves to survive the fast," Sherley said. "We don't find large rafts of carcasses; our sense is that they probably die at sea." The share of penguins that fail to moult rises when forage fish are scarce, the paper notes.

African penguins depend on small shoaling fish, above all sardines (Sardinops sagax) and anchovies. In every year except three since 2004, the study found, sardine biomass off western South Africa was below 25 per cent of its maximum abundance. Changes in sea temperature and salinity made sardine spawning less successful, while fishing pressure stayed high. Sherley said the share of the sardine stock taken by the fishery briefly reached 80 per cent in 2006, which probably made penguin deaths worse.

Off Namibia, once a stronghold of the species, rising ocean temperatures, changes in salinity and overfishing have caused the sardine population to effectively disappear, CNN reported. Where sardines are scarce, penguins have shifted partly to anchovies, which carry less fat and protein, and they have to swim farther offshore to find food, which costs both adult survival and the chicks waiting at the nest.

Azwianewi Makhado, a co-author, said Cape gannets are a good "sampler" of how many sardines and anchovies are available, because they forage widely across these fish stocks. Smaller colonies face a higher risk of dying out, the Mail & Guardian noted in its report on the study, because penguins forage less efficiently when there are few of them.

"Fisheries are a huge business, and we don't want fishing to stop completely; it is a vital part of our economy," Fraser-Knowles told CNN. No single factor explains the fall in fish stocks, she said, but "if we don't start fishing less, we're going to end up with a collapsed ecosystem."

SANCCOB was founded in 1968 and runs round-the-clock care for penguins and other seabirds hurt by injury, oil, disease and other problems. It admitted 948 penguins in 2025, and they were typically "thin, at best" when they arrived, Fraser-Knowles said. One adult brought in shortly before the CNN report weighed only 1.9 kg, less than half the ideal weight of about 4 kg. "The bodies that wash up and the ones that we treat, we can see this very, very strong trend," she said. "You don't find penguins in the wild that are the ideal body weight anymore."

The food crisis is hitting other seabirds too, among them cormorants; the Cape cormorant is itself an endangered species. SANCCOB researcher Albert Snyman keeps a small pile of stones in his laboratory as a reminder of how serious things have become. The stones were found in the stomachs of cormorant chicks that had been admitted to SANCCOB and later died. They help explain why those chicks did not thrive: the stones blocked them from absorbing the nutrients in the food that staff were feeding them. Stones have been found in the stomachs of penguin chicks as well, and Fraser-Knowles said abandoned chicks also often eat stones and sand.

Abandonment is a growing problem in its own right. African penguin parents normally take turns, one staying with the chicks while the other fishes. With extreme weather, more predators and longer fishing trips, parents are abandoning eggs and chicks more often, Fraser-Knowles said. When one parent does not come back, because it has been killed or held up by the search for food, the other may leave the nest to feed itself, in effect deserting the chicks.

Hunger affects the moult as well, said Dr David Roberts, a clinical veterinarian at SANCCOB. Penguins stay on land and fast for up to three weeks while they replace their worn feathers, which keep them warm, buoyant and able to hunt in cold water. Without enough fat the moult can be delayed or fail. "They come in (to SANCCOB) with really old, damaged feathers and we have to feed them and kickstart that molt cycle because they just can't do it in the wild anymore," Roberts told CNN.

Most of Roberts' surgery is for trauma, from pollution and plastic entanglement to, most often, bites from predators such as seals and sharks. Injuries and deaths from predators rise when fish are scarce, because hungry penguins are weaker and less able to escape.

Many colonies lie along major shipping routes or near harbours, where oil pollution remains a serious threat; noise from ships and injuries caused by vessels add to the pressure. Highly pathogenic avian influenza, a very contagious form of bird flu, and avian malaria are further dangers. "They don't breed successfully, they don't feed successfully and everything becomes more difficult for them," Fraser-Knowles said of birds living with habitat loss and disturbance.

Oil has hit the species hard before. After the MV Apollo Sea sank in 1994, about 10,000 oiled penguins were collected and cleaned, and fewer than half survived. On 23 June 2000 the iron ore carrier MV Treasure sank between Robben Island and Dassen Island and oiled about 19,000 adult penguins; another 19,500 un-oiled birds were taken from the islands and released about 800 km to the east so that the coast could be cleaned before they swam home. The rescue, run by SANCCOB with the International Fund for Animal Welfare, took more than three months. SANCCOB is the only organisation mandated by the South African government to respond to seabird emergencies along the country's coast.

The most important recent step concerned fishing. In 2022 the environment ministry had set interim closures to purse-seine fishing around six key breeding islands, to last until 2033. In March 2024 BirdLife South Africa and SANCCOB, represented by the Biodiversity Law Centre, sued the minister, arguing that the closures were "biologically meaningless" because they did not protect the birds' food from the commercial sardine and anchovy fleet.

In February 2025 the two industry bodies in the case, the South African Pelagic Fishing Industry Association (SAPFIA) and the Eastern and Southern Cape Pelagic Association (ESCPA), asked to meet the conservation groups. The settlement that followed, endorsed by the environment minister, was made an order of the Pretoria High Court on 18 March 2025. It replaced the interim closures with new ones around six colonies: Dassen Island, Robben Island, Stony Point, Dyer Island, St Croix Island and Bird Island. The closures run for 10 years, with a scientific review after six.

Kate Handley, executive director of the Biodiversity Law Centre, said the boundaries struck "the sweet spot between benefits to penguins and costs to industry". The closure around Robben Island went further than the NGOs had asked, the one around Stony Point covers nearly the whole core foraging range of that colony, and a 20 km closure was set around Bird Island in the Eastern Cape. The industry associations called it "a middle of the road compromise", with closures about halfway between the interim ones and what the conservation groups had sought. The six colonies hold about 76 per cent of the world's African penguins, the Mail & Guardian reported in December 2025.

CNN described the areas as no-take zones that keep extractive activity away from the feeding grounds. "According to the data, the no-take zone around Robben Island should stop the decline of that population just on that island by 2033, we hope, but of course, there are all these other factors at play," Fraser-Knowles said.

Since 2006, SANCCOB's chick bolstering project has taken in abandoned chicks, hand-reared them and released more than 10,000 penguins back into the wild, CNN reported.

Some of those birds have gone to De Hoop Nature Reserve on the southern Cape coast, where BirdLife South Africa, working with SANCCOB and CapeNature, set out to create a new colony; CNN called it the world's first man-made protected penguin colony and dated its establishment to 2021. Penguins had tried to breed at De Hoop from 2003 to 2008, reaching 18 pairs, before a predator thought to be a caracal killed several birds and the rest left. The project put up a 2.4-metre electrified fence, monitored around the clock, which a leopard breached in 2019 before the weak spot was fixed. Cement decoys and penguin calls played through a solar-powered speaker were used to draw birds in, and more than 140 hand-reared young penguins from SANCCOB were released there from 2021.

In late October 2022 the first two chicks hatched at the site. "I was speechless," said Christina Hagen, who leads the project for BirdLife South Africa. Pichegru cautioned at the time that colonies grow slowly and that the long-term answer was protecting the penguins' food. By February 2026, CNN reported, released penguins were breeding at De Hoop.

For the next five to 10 years, Fraser-Knowles said, success will need wild colonies to be stabilised, no-take zones to be widened beyond the current recommendations and quotas for sardine and anchovy fishing to be cut substantially. She said ordinary consumers can help by choosing livestock feed and pet food with less fish in it and by eating sustainably caught species listed in WWF South Africa's SASSI seafood guide.

"They are an indicator species, and their decline is signaling that our ecosystem is in serious trouble," she said. "If they don't have food security, then the trickle-down effect starts and it will end with humans."

Photo: Derek Keats / Wikimedia Commons (CC BY 2.0)

Sources: Jagonews24, CNN, Ostrich: Journal of African Ornithology, Mail & Guardian, The Guardian (via The Namibian), Mongabay, BirdLife International, TimesLIVE, Wikipedia