The current era is characterized by a global biological crisis, often referred to as the Sixth Mass Extinction, driven primarily by human activity. The rate at which species are disappearing is significantly higher than the natural background extinction rate observed in the geological record. This unprecedented loss affects every major biological group, threatening the stability of ecosystems worldwide. Understanding which species are most vulnerable is the first step toward effective conservation. The question of which animals are “going to be extinct” is addressed through rigorous scientific classification that determines the probability of a species vanishing from the wild.
How Scientists Determine Extinction Risk
The global authority for classifying the extinction risk of species is the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. This system provides a standardized, scientific framework for assessing a species’ conservation status based on rigorous criteria. The classification that corresponds most closely to “going to be extinct” is the Critically Endangered (CR) category, which denotes an extremely high risk of extinction in the wild.
A species is assigned the Critically Endangered status if it meets any of five quantitative criteria related to population decline or distribution size. Criteria include observing a population size reduction of 90% or more over ten years or three generations, or having a restricted geographic area of occupancy less than 10 square kilometers.
A species also qualifies if its total mature population numbers fewer than 50 individuals. The most definitive criterion involves a quantitative analysis showing an estimated probability of extinction in the wild of at least 50% within 10 years or three generations. These criteria ensure classification is based on verifiable, quantitative biological data, providing a clear scientific measure of vulnerability.
Species Facing Imminent Extinction
The Critically Endangered classification applies to thousands of species whose survival hangs by the narrowest margin. Among the most imperiled marine mammals is the Vaquita (Phocoena sinus), a small porpoise endemic to the northern Gulf of California. Its population is estimated to be fewer than 20 individuals, driven to collapse by entanglement in illegal fishing gillnets meant for other species.
On the African continent, several large terrestrial animals face this extreme risk, including the Black Rhino (Diceros bicornis). Despite intensive anti-poaching efforts, this species is relentlessly targeted for its horn, reducing its numbers to approximately 5,000 mature individuals. The loss of this megafauna has consequences for the structure of the savanna ecosystems they inhabit.
The crisis extends into the world’s rainforests, where the Tapanuli Orangutan (Pongo tapanuliensis) is considered the most endangered great ape species. Found only in a small, isolated area of Sumatra, Indonesia, its habitat is severely fragmented by agricultural expansion and infrastructure projects. With fewer than 800 individuals remaining, this primate is exceptionally vulnerable to further habitat disturbance.
Amphibians are also disproportionately represented in the highest risk categories, exemplified by the Axolotl (Ambystoma mexicanum). This unique salamander is now found almost exclusively in the remnants of its native habitat, the Xochimilco canals near Mexico City. Habitat destruction, water pollution, and the introduction of non-native fish species have decimated its wild numbers, pushing it to the brink.
Major Causes Accelerating Species Decline
The primary systemic driver of species loss is Habitat Destruction and Fragmentation, resulting from human land-use changes. The conversion of forests to agricultural land, the drainage of wetlands, and the expansion of urban areas directly eliminate the living spaces species depend upon. This leaves isolated populations in small, disconnected patches, making them susceptible to localized extinction events and genetic inbreeding.
A second major threat is Overexploitation, which includes unsustainable hunting, poaching, and commercial harvesting. The illegal wildlife trade, fueled by demand for exotic pets and traditional medicine, directly removes thousands of animals from the wild each year. Industrial fishing practices also result in significant bycatch, the accidental capture and death of non-target species.
Climate Change acts as a powerful multiplier of risk, rapidly altering environments faster than many species can adapt. Rising global temperatures cause shifts in weather patterns, ocean acidification, and sea-level rise, disrupting the balance of ecosystems. Species with highly specialized habitat requirements, such as those living on mountaintops or in polar regions, face an impossible challenge as their environment disappears.
The introduction of Invasive Species and Disease represents a powerful mechanism of decline. Non-native species often outcompete native wildlife for resources or prey upon them without having natural predators to control their populations. Furthermore, human activities, such as global trade and travel, facilitate the spread of novel pathogens, which can decimate vulnerable populations lacking natural immunity, particularly in amphibians.
Strategies to Prevent Further Extinction
Conservation efforts are generally categorized into two main approaches: in-situ (on-site) and ex-situ (off-site) protection. The most fundamental in-situ strategy involves the establishment and effective management of Protected Areas, such as national parks and wildlife reserves. These protected habitats safeguard the space and resources necessary for wild populations to recover and maintain their ecological functions.
Policy and international cooperation are important in mitigating threats faced by mobile or transboundary species. International agreements regulate the trade of endangered species and their products, aiming to dismantle the economic incentives for poaching. Enforcement of anti-poaching laws and the use of advanced monitoring technology, such as satellite tracking and genetic analysis, are crucial for protection.
When a species is at immediate risk of collapse, Captive Breeding and Reintroduction Programs become an essential ex-situ measure. These programs maintain a genetically viable population in human care, acting as an insurance policy against extinction in the wild. The offspring can eventually be released into secure or restored native habitats, effectively re-establishing wild populations as threats are reduced.