Twelve Species Along the IUCN Red List, From Least Concern to Critically Endangered

Rated Least Concern, the safest place on the scale. The atlas records an estimate of about one million birds and marks it as debated, since published global estimates range from one to two million mature individuals. The global population is very large, though some regional breeding colonies are declining. It flies from the high Arctic to the edge of the Antarctic pack ice each year.

Rated Near Threatened. The wild population fell from tens of millions to only a few hundred animals by the 1880s. The cited zoo fact sheet gives a total population of about 31,000 individuals, with 11,000 to 13,000 of them mature, and the atlas marks its own population estimate as debated.

Rated Vulnerable, with a recorded estimate of about 26,000 individuals. It hunts almost entirely from sea ice that forms and melts with the season, so the loss of that ice is the defining threat to the species rather than a side issue.

Rated Vulnerable after moving off the Endangered list in 2016, a change credited to habitat protection and captive breeding. The recorded estimate is about 1,864 animals, and its range is still split into more than thirty isolated forest pockets.

Rated Endangered, the first step into the highest threat band. Hunted to the edge of extinction in the twentieth century, it remains a small fraction of its pre-whaling numbers despite decades of legal protection.

Rated Endangered. The atlas records a combined estimate near 415,000 for savanna and forest elephants and marks it as debated, because forest elephant counts carry wide uncertainty. The largest living land animal is also a keystone species, since its feeding and movement shape vegetation across the savanna for many other animals.

Rated Endangered, with a recorded estimate of about 595,000. It breeds on the sea ice fringing Antarctica through the southern winter, and its breeding success depends on stable ice, which makes it a closely watched indicator of Antarctic climate change.

Rated Endangered in 2018, with a declining population. The largest freshwater dolphin lives only in the Amazon, Orinoco and Madeira river basins, and one recorded pressure is direct hunting for use as fishing bait or predator control.

Rated Endangered, with a recorded estimate of about 1,063 animals in two isolated mountain populations. Anti-poaching patrols, veterinary care and managed tourism have made it one of the few great ape populations increasing rather than declining.

Rated Critically Endangered, the top threat category. Published estimates for the wild population range from under 400 to about 600, and the atlas marks the figure as debated. It survives only on the island of Sumatra, in forest patches that keep shrinking under logging and conversion to plantations.

Rated Critically Endangered. White band disease from the late 1970s, followed by warming-driven bleaching and hurricane damage, has eliminated an estimated 80 to 98 percent of its Caribbean population, one of the fastest documented collapses of any reef-building coral.

Rated Critically Endangered, with survey estimates in the low double digits and falling, and fewer than 10 to 13 individuals estimated in 2024. No published figure is treated as a precise census, and this is the smallest population on this path. Nearly every death is accidental bycatch in gillnets set illegally for the totoaba, so its crisis is a byproduct of another species' poaching.