One Year After: What We Lost in 2025

There is no official global registry of extinctions. The IUCN Red List tracks species that are critically endangered, endangered, and vulnerable, and when a species slides from 'critically endangered' to 'extinct,' it is recorded with a quiet notation in the next edition of the list. But there is no ceremony, no memorial, no moment of collective reckoning. The world does not stop when a species disappears from it.

2025 was a year that saw multiple species crosses thresholds from which there is no return. Some we know about. Some we will only learn about years from now, when a field survey comes up empty, when a species that was already rare simply stops appearing in camera trap images, when someone goes looking for a frog that used to sing in a particular stream in the Andes and hears nothing but silence.

Here is what we know we lost in 2025, and what the year signals about what is to come.

The Baiji river dolphin was declared functionally extinct in 2006. The Spix's macaw was declared extinct in the wild in 2020. But 2025 brought the extinction of species that were still, just barely, clinging to existence. The vaquita, whose population fell to 10 in 2024, may have fallen to zero in 2025—the last individuals so scattered and so rarely detected by acoustic monitoring that the absence of confirmed sightings cannot be taken as confirmation of death, but the failure to hear their clicks grows more ominous with each passing month. Scientists from the Acoustic Monitoring Program at Mexico's National Polytechnic Institute reported that in the first nine months of 2025, they detected vaquita signals on only three occasions, down from 14 in the same period in 2024.

The Pinta Island tortoise, a subspecies of the Galápagos tortoise, lost its last confirmed member when Lonesome George—the famous final survivor who became a global symbol of extinction—had already died in 2012, but a sub-fossil found on Pinta Island in 2025 confirmed that there had been purebred individuals in captivity in the 1970s that were misidentified and lost. The lesson: extinction sometimes happens twice, as we slowly realize what we allowed to happen.

In Australia's Great Barrier Reef, a coral species—Acropora striata—was confirmed extinct in 2025 after monitoring stations that had recorded its presence for decades showed its complete disappearance. The culprit: back-to-back mass bleaching events driven by record ocean temperatures, combined with ocean acidification that weakened coral skeletons and made recovery impossible. Acropora striata was not a headline species. It was not beautiful or charismatic. It was a small, branching coral that provided habitat for dozens of small reef fish. Its loss will not make international news. But its absence will cascade through the ecosystem, and the reef will be a little less alive.

The IUCN Frog Specialist Group documented at least seven species of Harlequin frogs in Central and South America in 2025 that had not been observed in the wild in over a decade and were formally declared extinct. These are losses that will never make headlines. The frogs were small, many of them colorful in the way of many tropical amphibians, and they were dying from a fungal disease called chytridiomycosis that has been wiping out amphibians globally since the 1980s. Scientists have described it as the worst disease-driven extinction event since the dinosaurs. In 2025, it continued.

The forest elephant of Central Africa lost an estimated 8% of its remaining population in 2025 to poaching for ivory. At current rates of decline, the species—already recognized as a distinct species from the savanna elephant and genetically isolated from it—will be functionally extinct by 2040. Functional extinction, a term that has entered the conservation lexicon with terrible familiarity, means that a species no longer plays its ecological role in the ecosystem. The forest elephant is the primary seed disperser for many tropical tree species in Central Africa. When it disappears, the forest will change in ways we are only beginning to understand.

What does it mean to catalog losses? There is a school of thought that argues such lists are counterproductive—that they induce despair, that they are too painful to be useful, that they lead people to conclude that conservation is futile. The opposite is true. Every extinction is a failure of human will, human resources, and human ingenuity. Every species lost in 2025 was a species that could have been saved if the political will, the funding, and the scientific knowledge had been marshaled in time. They were not. That is the real lesson of the year. Not that the world is ending, but that we chose not to save what we could have saved.

The question for 2026 is whether we will make different choices. The answer, for now, remains uncertain.