An IUCN Red List Critically Endangered species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of 2021, of the 120,372 species currently tracked by the IUCN, there are 8,404 species that are considered to be Critically Endangered.
Leptolaena abrahamii is a species of flowering plant in the family Sarcolaenaceae. It is found only in Madagascar. Its natural habitat is mid-elevation humid tropical forests. It is threatened by habitat loss.
Lemurophoenix halleuxii is a species of palm tree, the only species in the genus Lemurophoenix. It is found only in Madagascar. It is threatened by habitat loss and overcollection. There are perhaps 300 mature individuals remaining in the wild.
Khaya madagascariensis is a species of plant in the family Meliaceae. It is found in Comoros and Madagascar.
Melanophylla alnifolia is a species of plant in the Torricelliaceae family. It is endemic to eastern Madagascar. Its natural habitat is tropical moist lowland and montane forests. It is threatened by habitat loss.
Nothofagus alessandrii, the ruil, is a species of plant in the family Nothofagaceae, commonly known as the southern beeches. It is endemic to Chile, occurring chiefly in the Chilean matorral ecoregion. It is threatened by habitat loss. The species is protected within Los Ruiles National Reserve.
Polyscias nothisii is a species of plant in the family Araliaceae for which no name has yet been published. It is endemic to New Caledonia. It is found in dry forest at low altitude on calcareous or volcano-sedimentary substrate. Main threats are habitat degradation caused by recurrent bushfires and invasive species as well as land clearing. Its extent of occurrence (EOO) and area of occupancy (AOO) are estimated to be of 1,536 km2 and 44 km2 while the number of locations is estimated to be five. Polyscias nothisii is therefore assessed as Endangered (EN) with criteria B1ab(iii)+2ab(iii) with a continuing decline of habitat quality.
Monachoides vicinus is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Hygromiidae, the hairy snails and their allies.
The Cantabrian capercaillie is a subspecies of the western capercaillie in the grouse family Tetraonidae. It is one of two subspecies found in Spain.
A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve.
Migmathelphusa olivacea is a species of freshwater crab found in Lake Poso on the Indonesian island of Sulawesi. It is the only species in its genus. It is listed by the IUCN as Endangered, given "its extent of occurrence and area of occupancy is less than 500 square kilometres (190 sq mi)", and its individuals being found in less than five locations. There is also a "decline in the extent and quality of its habitat and it is not found in a protected area". Being found around a lake, "present and future threats to this species include human-induced habitat loss/degradation due to population increases and industrial and agrarian development".
Betula klokovii is a species of tree restricted to Ukraine. These trees grow on sandy hills in steppe grasses and dry chalkstone or in open woodlands. It is only found in two mountains: Strakhova and Maslyatyn, near Kremenets in the Ternopil region.
Ellen Clark's crayfish was named by Morgan "in respect of Ellen Clark’s pioneering parastacid studies". It is restricted to headwater reaches of highland streams draining the plateau and feeding the Hastings and Forbes rivers, at elevations ranging from 670–1,150 metres (2,200–3,770 ft) asl. The species is assessed as "Endangered" based on an extent of occurrence (EOO) of 198 square kilometres (76 sq mi), an area of occupancy (AOO) of 68 square kilometres (26 sq mi) occurrence at one to two threat-based locations and a speculated decline in area, extent and quality of habitat due to climate change. This species is fully protected by the Australian government regulations, hence no trade or commercial utilization of the species is allowed. Horwitz and Richardson classified crayfish burrows based on their relationship to the water table, into three categories:
Mediusella bernieri is a plant in the family Sarcolaenaceae. It is endemic to Madagascar.
Pittosporum mackeei is a species of plant in the Pittosporaceae family. It is endemic to New Caledonia.
Euastacus guruhgi is a species of freshwater crayfish found in the Australian state of New South Wales. It has an estimated extent of occurrence of 80 square kilometres (31 sq mi) and an area of occupancy of 7.5 square kilometres (2.9 sq mi) where it occurs fragmentedly. The species has been assessed as a critically endangered species due to a continuing decline in the quality of its habitat due to the invasive exotic species in the area, some of which predate upon this species. Furthermore, there is a continual destruction of its suitable rainforest habitat. E. guruhgi also faces the consequences of global warming; as a restricted range species, it is dependent on cool headwater streams and a slight increase in the temperature of the water could rapidly eradicate the species. There are no specific conservation measures for this species in place but the distribution range of the E. guruhgi falls within the Mount Warning and Wollumbin national parks. In New South Wales, there is a minimum recreational size limit of 90 mm orbital carpace length for any spiny crayfish. E. guruhgi does not attain that size, and is thus, indirectly protected by this restriction.
Endangered species, as classified by the International Union for Conservation of Nature (IUCN), are species which have been categorized as very likely to become extinct in their known native ranges in the near future. On the IUCN Red List, endangered is the second-most severe conservation status for wild populations in the IUCN's schema after critically endangered. In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered worldwide. The figures for 1998 were 1,102 and 1,197 respectively.
Quercus radiata is an endangered species of oak native to Mexico.
Hernandia voyronii, commonly known as Hazomalany, is a species of plant in the Hernandiaceae family. It is endemic to Madagascar.
Carausius scotti, or Scott's stick insect, is an insect species endemic to Silhouette Island in the Seychelles. It was assessed as critically endangered in The IUCN Red List of Threatened Species in 2007 as a restricted range species with an area of occupancy of 10 square kilometres (3.9 sq mi) with an estimated extent of occurrence (EOO) of 18 square kilometres (6.9 sq mi). The species is primarily threatened with declining woodland habitats due to invasive plants and also climactic factors such as droughts. It is present in the protected area of Silhouette National Park as a part of conservation efforts, however more conservation actions are needed, as well as further research to determine population sizes and trends.
