Extinction, the permanent disappearance of a species from Earth, is a natural process. While often associated with prehistoric eras, species loss continues today, with numerous animal species confirmed extinct since 2000.
The Reality of Recent Extinctions
Extinction is a contemporary issue, with species disappearing at rates far exceeding natural background levels. Scientists estimate current extinction rates to be hundreds to thousands of times higher than average evolutionary timescales. This accelerated loss is largely driven by human activities.
Notable Species Lost
Since the year 2000, several prominent animal species have been declared extinct. The Pyrenean Ibex (Capra pyrenaica pyrenaica), a wild goat subspecies native to the Pyrenees mountains, was declared extinct in 2000. Despite a cloning attempt in 2003, which resulted in a live birth that survived only minutes, the subspecies remains lost.
The Western Black Rhinoceros (Diceros biceros longipes), a subspecies of black rhinoceros that once roamed the savannas of central Africa, was officially declared extinct in 2011. Extensive poaching for its horn led to its severe decline.
In 2012, the Pinta Island Tortoise (Chelonoidis nigra abingdonii) became extinct with the death of its last known individual, Lonesome George, at the Galapagos National Park. This tortoise suffered from overhunting and habitat destruction by introduced goats.
The Formosan Clouded Leopard (Neofelis nebulosa brachyura), a subspecies endemic to Taiwan Island, was declared extinct in 2013 after surveys failed to find individuals since 1986. Logging activities that fragmented its forest habitat contributed to its disappearance.
The Bramble Cay Melomys (Melomys rubicola), a small rodent found only on Bramble Cay, a tiny island in the Great Barrier Reef, was declared extinct in 2015. This marked the first mammalian extinction attributed primarily to human-induced climate change, which caused habitat loss due to rising sea levels and storm surges.
The Spix’s Macaw (Cyanopsitta spixii), a vibrant blue parrot native to Brazil, was declared extinct in the wild in 2018.
In 2020, the Splendid Poison Frog (Oophaga speciosa), a brightly colored amphibian from Panama, was declared extinct. Its decline was linked to deforestation and the chytrid fungus outbreak.
Also in 2020, the Smooth Handfish was declared extinct, marking the first modern marine fish extinction.
Factors Contributing to These Losses
Recent extinctions are primarily driven by a combination of human-induced pressures on natural environments.
Habitat loss and degradation stand out as the foremost contributors, largely stemming from land and sea use changes such as agricultural expansion, urbanization, and deforestation. These activities fragment ecosystems, leaving species with insufficient space and resources to survive.
Direct exploitation of natural resources, including overhunting, overfishing, and illegal wildlife trade, also plays a significant role in pushing species toward extinction. This pressure directly reduces population sizes, often beyond their capacity to recover.
The introduction of invasive alien species poses another severe threat, as these newcomers can outcompete native species for resources, introduce diseases, or prey upon vulnerable populations.
Pollution, from chemical contaminants to plastic waste, degrades habitats and directly harms wildlife, particularly impacting freshwater and marine ecosystems.
Climate change, driven by increasing greenhouse gas concentrations, exacerbates these issues by altering habitats, changing weather patterns, and increasing the frequency of extreme events. The combined effect of these factors creates complex challenges for species survival.
Confirming Extinction
Determining that a species is extinct is a rigorous scientific process, as it involves proving an absence, which can be challenging.
The International Union for Conservation of Nature (IUCN) establishes the criteria for declaring a species extinct. A species is considered extinct when there is no reasonable doubt that the last individual has died.
This conclusion is typically reached after exhaustive surveys in known and expected habitats, conducted over an appropriate timeframe, have failed to record any individuals. Scientists assess factors like the intensity of threats a species faces, the reliability of past sightings, and the quality of survey efforts.
While a “50-year rule” was once informally considered, modern guidelines emphasize comprehensive data analysis, including population size, geographic range, and habitat degradation. The IUCN Red List categorizes species, with “Extinct” (EX) being the final designation.