See All Key Ideas
SAN JUAN DE MARCONA, Peru — First, there was the H5N1 avian influenza of 2022, then El Niño arrived in 2023, disrupting coastal waters and fish availability. For Peru’s Humboldt penguins, the only species of penguins that breeds in the country, the burden was too heavy: Its population dropped by two-thirds between 2022 and 2025. Still recovering, the species is now facing a super El Niño that could further undermine its future.
In early June, the Secretary-General of the United Nations, António Guterres, warned: “The science is clear: El Niño is arriving on our doorstep in the coming months with 90% certainty. The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed.”
Scientists studying the Humboldt penguins (Spheniscus humboldti) in Peru say that they are already feeling the impact of the 2026 El Niño as warmer coastal waters drive the cold current carrying the main prey fish, Peruvian anchovy (Engraulis ringens) or anchoveta, deeper and further offshore. That means the penguins and other seabirds are forced to undertake longer fishing trips to get enough food to breed or feed chicks.
Scientists studying El Niño say the gaps between the events are getting smaller and the effects are more unpredictable. “Climate change is driving more frequent and more severe El Niño events,” Andres Lescano, director of Clima, the Latin American Center of Excellence in Climate Change and Health, told Mongabay. The Humboldt penguin nests and rests in the coastal deserts of southern Peru and northern Chile’s arid Pacific coastline and offshore islands, which are directly affected by El Niño events.
In Punta San Juan de Marcona National Reserve, one of the penguins’ major nesting colonies in southern Peru, the number of penguin nests has halved between April and May 2026, from 190 on April 10 to 94 on May 30, according to scientists’ recordings.
“They abandoned their nests,” Peruvian biologist Susana Cardénas, the director of the Punta San Juan program, told Mongabay at the 54-hectare (133 acres) marine reserve, where she leads a team that monitors the Humboldt penguin population.
“There was a reduction in food availability and when the parent that stays with the egg gets too hungry, it leaves,” she said. “The [Humboldt] penguin is the sentinel species, and its breeding failure is a sign that it’s going to get worse. It’s going to be a really bad year for all the seabirds.”
The Humboldt penguin breeds from April to August and from September until December, before other seabirds, so it is the first to be impacted by the shortage of food caused by the warmer sea surface temperatures, which have risen by up to 2° Celsius (3.6° Fahrenheit) in the eastern equatorial Pacific, according to Peru’s official National Study of the El Niño Phenomenon.
Punta San Juan de Marcona serves as a marine biodiversity hotspot with large breeding populations of seabirds, including the Humboldt penguin, the Peruvian pelican (Pelecanus thagus), the Guanay cormorant (Leucocarbo bougainvillii), the Peruvian booby (Sula variegata), and hundreds-strong breeding colonies of Peruvian fur seal (Arctocephalus australis ssp) and South American sea lions (Otaria byronia), as well as a small population of marine otters (Lontra felina).
The Humboldt current, which flows up from Antarctica, allows the upwelling of nutrients, which supports a huge biomass of anchoveta as well as a variety of seabirds, sea lions and fur seals.
Peru’s coast is one of the third or fourth richest fisheries in the world. However, as sea surface temperatures began to rise, Peru’s Production and Fisheries Ministry announced on June 11 that it was closing the anchoveta fishing season in the country’s north-central coast as a “conservation measure” based on scientific information from the Peruvian Sea Institute (IMARPE).
The burden of disease
After the H5N1 highly pathogenic avian influenza (HPAI) hit South America in late 2022, the virus caused a massive drop in seabird and marine mammal numbers in 2022 and 2023, on its Pacific and Atlantic coasts.
In Peru alone, the virus killed about 558,000 seabirds across 14 species (including cormorants, boobies, pelicans, seagulls, terns and penguins) and 11,000 sea lions between December 2022 and December 2023, according to a 2025 study published by the Society for Conservation Biology. Peru’s seabird population was particularly hard hit, accounting for the vast majority of bird deaths, with an estimated 667,000 total on South America’s Pacific and Atlantic coasts.
But bird species continued to be battered by the ensuing El Niño. As sea temperatures peaked at nearly 4 °C (7.2° F) higher than normal in the last year, penguins and other seabirds were forced to undertake longer fishing trips, often exposing the chicks or fledglings to predators, starvation, nest abandonment by the parent birds, or, in some cases, the shortage of food can mean that the penguins do not breed at all.
In Punta San Juan, not a single penguin nest was recorded in 2023. “This is unprecedented since records began,” explained Cárdenas, who runs the Punta San Juan program through the Centre for Environmental Sustainability at Lima’s Cayetano Heredia University. “The penguins were getting ready for their breeding season; the marine conditions changed and they did not come back to breed.”
A census of the penguins in 34 islands and peninsulas along the Peruvian coast showed that their numbers dropped from 15,663 in 2022 to approximately 5,400 in 2025, according to a census carried out by Cayetano Heredia University and the NGO Peruvian Association for the Conservation of Nature (APECO) and other organizations, along with Peru’s Forestry and Wildlife Service, SERFOR.
Since 2023, constant monitoring of the population by scientists at the Punta San Juan reserve has detected a slow recovery in numbers, until the early effects of the 2026 El Niño caused a new wave of nest abandonment. In July, local Peruvian media was reporting the deaths of marine birds, including penguins, as well as marine mammals such as South American sea lions along the coast due to a lack of food.
As the Humboldt Penguin faces an onslaught of threats, Cárdenas and other scientists in Peru are asking the government to change its conservation status from endangered to critically endangered. The move had been approved by a supreme decree in 2021, but it still needs presidential approval to be signed into law.
Scientists from Peru and Chile are also pushing the IUCN Red List of Threatened Species to update the classification of the penguin from vulnerable to endangered amid the decline in its numbers.
In January 2025, SERFOR announced a National Conservation Plan for the Humboldt penguin and the sea otter, but, despite a series of workshops with conservationists and environmental nonprofits, the plan has yet to be published.
Banner image courtesy of Punta San Juan program. Image by Andre Baertschi.
Citation:
Kuiken, T., Vanstreels, R. E. T., Banyard, A., Begeman, L., Breed, A. C., Dewar, M., … & Wille, M. (2026). Emergence, spread, and impact of high‐pathogenicity avian influenza H5 in wild birds and mammals of South America and Antarctica. Conservation Biology, 40(1), e70052. doi:10.1111/cobi.70052
FEEDBACK: Use this form to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.
Source:
news.mongabay.com