Biological extinction refers to the permanent, global disappearance of a species, marking the definitive end of its lineage. The year 2020 saw multiple species formally moved into the “Extinct” category on global conservation lists, a sobering reminder of the ongoing loss of biodiversity. These formal declarations often serve as milestones, confirming losses that may have occurred years or even decades prior. Examining the species declared extinct in 2020 reveals patterns about where and how this loss is occurring.
Species Declared Extinct in 2020
The 2020 updates confirmed the loss of several unique species of amphibians, fish, and a notable marine species. The Smooth Handfish (Sympterichthys unipennis), a distinctive bottom-dwelling fish from the waters off Tasmania, was declared extinct after having not been seen since 1802. This designation marks the Smooth Handfish as the first marine fish species formally declared extinct in modern history.
Amphibians in Central and South America were disproportionately represented in the 2020 declarations, largely due to the devastating impact of the chytrid fungus. The Splendid Poison Frog (Oophaga speciosa), an arboreal species from Panama, was formally listed as Extinct, with its last confirmed sighting dating back to 1992. Similarly, the Chiriqui Harlequin Frog (Atelopus chiriquiensis), native to the border region of Costa Rica and Panama, was declared lost, having last been observed in 1996. The Aragua Robber Frog (Pristimantis anotis) was also confirmed extinct, having not been seen in nearly five decades.
Freshwater ecosystems also suffered confirmed losses. Lake Lanao in the Philippines, known for its endemic fish, saw the formal loss of multiple cichlid species from the genus Barbodes. These species, including Barbodes amarus and Barbodes manalak, were last observed in the 1970s and 1980s, their extinction confirmed after decades of unsuccessful searching.
While the Spix’s Macaw, a bright blue bird from Brazil, was declared Extinct in the Wild in 2020, a small number of individuals are maintained in captivity for a potential future reintroduction program. This classification means the species no longer survives in its natural habitat. These declarations highlight that many confirmed extinctions involve smaller, less visible species lost in isolated freshwater or mountain ecosystems.
The Formal Process of Declaring Extinction
The formal process of declaring a species extinct is a rigorous and lengthy procedure governed by international bodies such as the International Union for Conservation of Nature (IUCN). This process is designed to prevent premature declarations that could halt last-ditch conservation efforts. Species are first placed into the “Critically Endangered” category, and if they are suspected to be lost, they receive the designation “Critically Endangered (Possibly Extinct).”
Moving a species from this “Possibly Extinct” status to the definitive “Extinct” category requires comprehensive, systematic surveys across the species’ entire known or suspected range. These exhaustive searches must be conducted over a period appropriate to the species’ life cycle and habitat, and they must consistently fail to find any individuals. The scientific caution inherent in this process explains why species like the Smooth Handfish, last seen in the early 1800s, were only officially declared extinct in 2020.
The time lag between the last sighting and the formal declaration is often measured in decades to ensure non-existence is confirmed beyond a reasonable scientific doubt. This methodology protects species that may survive in small, undiscovered pockets, such as in remote habitats or in the deep ocean, where detection is difficult.
Primary Drivers of Recent Species Loss
The 2020 extinctions point to a few major, systemic pressures driving species loss globally.
Habitat Destruction and Fragmentation
Habitat destruction and fragmentation remain the most widespread cause, particularly for terrestrial and freshwater species. Deforestation for agriculture and development eliminates the necessary living space for highly localized species, such as the endemic frogs of Central America and the unique fish of Lake Lanao.
Invasive Species and Disease
The introduction of non-native organisms, including both invasive species and disease, represents another powerful driver of extinction. The loss of numerous amphibian species, including the Splendid Poison Frog, is directly linked to the spread of the pathogenic chytrid fungus, which has decimated amphibian populations worldwide. Invasive species can also introduce new predators or competitors to vulnerable, isolated ecosystems.
Climate Change
Climate change is increasingly recognized as a significant factor, altering habitats faster than many species can adapt. Rising global temperatures and changing weather patterns contribute to habitat degradation and stress on populations already weakened by other human-related pressures. The confirmed extinctions of 2020 illustrate how the combined effects of these environmental stressors push localized, vulnerable populations past the point of recovery.