Elephant

Elephants are placed in the family Elephantidae, within the order Proboscidea. The African bush elephant is classified in the genus Loxodonta.

African elephants were formerly treated as a single species listed as Vulnerable. The two species were then assessed separately for the IUCN Red List for the first time, following the emergence of new genetic evidence.

Fish and Wildlife Service lists the African forest elephant under the scientific name Loxodonta cyclotis. The same agency lists the Asian elephant under the scientific name Elephas maximus and categorizes it as a mammal.

Tusks are a conspicuous feature of elephant anatomy, though their distribution varies by species. In the African bush elephant, both sexes carry two thick, ivory tusks that are curved and can reach up to 350 cm in length ^{1Loxodonta africana (African bush elephant) · Animal Diversity Web, University of Michigan Museum of Zoology ↗}.

The trunk of an adult male elephant weighs about 130 kg and is capable of lifting a load of about 250 kg ^{5Elephant · Encyclopaedia Britannica ↗}. Its tip differs between the two genera: Asian elephants have one fingerlike projection at the tip of the trunk, while African elephants have two ^{6Elephas maximus (Asiatic elephant) · Animal Diversity Web, University of Michigan Museum of Zoology ↗}.

The African elephant's range extends across 37 countries in sub-Saharan Africa. Within this vast area, the population is unevenly distributed: an estimated 70% of the animals are found in Southern Africa, 20% in Eastern Africa, 6% in Central Africa and 3% in West Africa. The African savanna elephant, one of the three living species, is currently found in 23 countries. The forest elephant, by contrast, has a more restricted natural distribution and is thought to occupy only a quarter of its historic range today, with the largest remaining populations found in Gabon and the Republic of the Congo.

The Asian elephant, the largest land mammal on the Asian continent, inhabits dry to wet forest and grassland habitats in 13 range countries spanning South and Southeast Asia. Its habitats are varied, including grasslands, tropical evergreen forests, moist deciduous forests, and scrub forests. An average of 70% of Asian elephants are found outside protected areas today.

Rapid land use change by humans is driving the direct loss and fragmentation of habitat for African savanna elephants and is an increasing threat to populations across their range.

Among African elephants, females are social animals that live in herds of 6 to 70 members, ordered along matriarchal lines, and the alpha elephant tends to be the biggest and most dominant. The social unit of the Asian elephant takes a different shape: clans consist of related females and their offspring bound by strong social bonds, usually numbering between 5 and 20 individuals. These Asian clans are not fixed in size, as larger groups form and break apart depending on the season, habitat, and other conditions.

Males enter a distinctive reproductive condition. Male elephants experience a unique, rut-like sexual state called musth, which allows them access to females and reduces aggression among males. In the African forest elephant, males compete for access to estrus females, and musth is a hormonal state marked by increased aggression during which the male secretes a fluid from the temporal gland between the eye and ear.

Elephant society extends well beyond the animals immediately in view. Like other elephants, African forest elephants communicate among widely dispersed social groups through low-frequency sounds of 5 Hz. Communication is also individual in character: wild African elephants address one another with individually specific calls, probably without relying on imitation of the receiver. Evidence for this comes from experiments in which elephants responded differently to playbacks of calls originally addressed to them compared with calls addressed to a different individual.

The Asian elephant is a generalist feeder, capable of consuming more than 100 species of plants. Its diet spans bamboo, sugarcane, crops, the roots of trees, flowers, fruit, seeds, grains, and the bark of trees. The trunk is the instrument of this varied feeding, allowing the animal to grasp many types of food.

In the African elephant, the muscular trunk is able to grab objects. The trunk is not merely a grasping limb but a suction device as well. Elephants filmed at Zoo Atlanta were shown to use suction to grab food, a behaviour previously thought to be restricted to fishes.

The mechanics of this suction are remarkable. Experiments on liquid suction showed that elephants can expand the volume of their trunk by up to 64% in order to carry more water. On the basis of the pressures applied, the same study estimated that elephants can inhale at speeds of over 150 metres per second, nearly 30 times the speed of a human sneeze.

The length of pregnancy differs somewhat between the major elephant groups. For the African bush elephant, the gestation period is about 22 months, though it is strongly influenced by environmental factors. In the Asian elephant, gestation runs approximately 20 to 23 months on average.

Newborn African elephants weigh between 90 and 120 kg, with 100 kg being the average birth weight. Among Asian elephants, calves do not require nursing for survival after 2 years of age, but weaning does not occur until about 4 years of age. The typical age of independence for the Asian elephant is 5 years.

African elephants live an average of 60 to 70 years in the wild. The expected lifespan of the Asian elephant is about 60 to 70 years in both the wild and in captivity. For the Asian species, tooth wear limits the lifespan.

The three living elephant species — the African savanna elephant, the African forest elephant and the Asian elephant — are each assessed on the IUCN Red List of Threatened Species, and none is free of threat. Within the Asian elephant, the Sumatran subspecies is listed as Critically Endangered ^{14Elephas maximus (Asian Elephant) — IUCN Red List assessment 2019 · IUCN Red List of Threatened Species ↗}.

For the Asian elephant, the Endangered listing rests on a population size reduction inferred to be at least 50% over the last three generations, based on a reduction in its area of occupancy and the quality of its habitat ^{14Elephas maximus (Asian Elephant) — IUCN Red List assessment 2019 · IUCN Red List of Threatened Species ↗}.

Protective measures have been applied at the international and national levels. Under the U.S. Endangered Species Act, African elephants are classified as threatened and Asian elephants as endangered ^{15Elephant Ivory FAQs · U.S. Fish & Wildlife Service ↗}. For intrastate sales of African elephant ivory under U.S. federal law, the ivory must be shown to have been lawfully imported before January 18 1990, when the species was listed in CITES Appendix I ^{15Elephant Ivory FAQs · U.S. Fish & Wildlife Service ↗}. Citing a rise in international trade in live African elephants, the U.S. Fish and Wildlife Service proposed amending the 4(d) rule of the Endangered Species Act to benefit conservation in the wild and improve the welfare of captive elephants ^{16African Savannah Elephant (Loxodonta africana) · U.S. Fish & Wildlife Service ↗}.

Conservation action on the ground has produced some grounds for measured optimism. Anti-poaching measures, together with more supportive legislation and land use planning that seeks to foster human-wildlife coexistence, have been key to successful elephant conservation ^{2African elephant species now Endangered and Critically Endangered · IUCN (news release, Gland) ↗}.

The number of African elephants fell from an estimated 1.3 million in 1979 to 750,000 in 1987, and estimates from the review suggested about 625,000 remained ^{17The Ivory Trade and the Future of the African Elephant (Ivory Trade Review Group) · Pachyderm — Journal of the African Elephant Specialist Group ↗}. The African Elephant Status Report 2016 estimated a continental population of 415,428 elephants for both African elephant species combined and reported a decline of approximately 111,000 elephants from 2006 onward ^{8Loxodonta africana (African Savanna Elephant) — IUCN Red List assessment 2021 · IUCN Red List of Threatened Species ↗}. Population size estimates collated across all range countries as of 2018 suggest a global Asian Elephant abundance of 48,323–51,680 individuals in the wild ^{14Elephas maximus (Asian Elephant) — IUCN Red List assessment 2019 · IUCN Red List of Threatened Species ↗}.

The decline of the African forest elephant has been severe: its numbers fell by more than 86% over a period of 31 years. The African savanna elephant fared little better, with its population decreasing by at least 60% over the last 50 years. An analysis of estimates drawn from 334 localities indicates a reduction of more than 50% of the continental African savanna elephant population over the past three generations of 75 years, a reduction understood to be continuing and likely irreversible. A generation length of 25 years is used for the African savanna elephant, based on life-table analysis of culled family groups in South Africa and a 14-year study of savanna elephants in Kenya.

Habitat loss has been especially acute on Sumatra, where over 69% of potential elephant habitat has been lost within just one generation, the last 25 years.

The proboscideans, the order of animals that includes elephants, were a diverse and widespread group of herbivores that first appeared in Africa about 60 million years ago. Among the elephant ancestors discovered, Eritherium is the smallest, oldest and most primitive, growing to about 60cm and feeding on wet vegetation during the Paleocene epoch in what is now Morocco. The living elephants belong to the family Elephantidae, within the order Proboscidea.

Proboscideans that expanded from Africa into new habitats evolved 25 times faster than the relatives they left behind, resulting in three to four different species sometimes coexisting in one space. Early humans became effective hunters of large animals around 1.5 million years ago, but the final peak of proboscidean extinction came much earlier, at around 2.4 million years ago.

The elephants of north-east Borneo are genetically distinct from all other living elephant populations and may have been isolated on the island for hundreds of thousands of years, since Borneo was connected to the mainland during the ice ages. Fossils from Bethlehem excavated in the 1930s are probably more than three million years old and may be the earliest record of the mammoth and Asian elephant lineage outside Africa. Remains of Elephas hysudricus, considered ancestral to the living species Elephas maximus, have been identified from sites in Jordan and Israel, some of them dating to as late as 300,000 years ago.