Elephants are the largest living land animals, and there are three species rather than the two most references still give. They have the longest gestation of any mammal, they communicate below the range of human hearing, they are among the few animals that appear to attend to their dead, and the recent history of all three species is dominated by the ivory trade.

A herd of African bush elephants. Groups are led by the oldest female, and the knowledge she carries about water and routes is measurable in the survival of the group during drought.
A herd of African bush elephants. Groups are led by the oldest female, and the knowledge she carries about water and routes is measurable in the survival of the group during drought.Credit: Benh LIEU SONG / Benh LIEU SONG (CC BY-SA 2.0).

The African bush elephant, Loxodonta africana, is the largest, of open savanna and the biggest land animal alive. The African forest elephant, Loxodonta cyclotis, is smaller and darker with straighter, downward-pointing tusks and rounder ears, and lives in the rainforest of the Congo basin and West Africa. The Asian elephant, Elephas maximus, is smaller again, with a domed forehead, smaller ears and, in most populations, tusks on some males only.

That the two African elephants are separate species was established genetically and confirmed by a 2010 study showing they diverged several million years ago, comparable to the split between the Asian elephant and the extinct mammoth. The IUCN did not assess them separately until 2021, and a great deal of published material still treats them as one.

The reassessment mattered because it changed the conservation picture immediately: the forest elephant is Critically Endangered and the bush elephant Endangered, a sharper reading than the single Vulnerable listing they had shared.

A size comparison of an elephant against a human figure. Large bush elephant bulls reach around three and a half metres at the shoulder and six tonnes.
A size comparison of an elephant against a human figure. Large bush elephant bulls reach around three and a half metres at the shoulder and six tonnes.Credit: Asier Larramendi (CC BY 4.0).

The trunk is a fusion of nose and upper lip containing no bone and, by common estimates, on the order of forty thousand muscle fascicles. It is used for breathing, smelling, drinking, feeding, washing, sound production, touch and fighting, and it can lift very heavy loads while also picking up a single seed. African elephants have two opposing finger-like tips at the end; Asian elephants have one.

The molar of an adult African elephant. The ridged grinding surface wears down with use, and an elephant grows only six sets in a lifetime.
The molar of an adult African elephant. The ridged grinding surface wears down with use, and an elephant grows only six sets in a lifetime.Credit: Hectonichus (CC BY-SA 3.0).

The teeth set the lifespan. Elephants do not replace molars vertically as we do but horizontally: a new tooth grows at the back of the jaw and moves forward, pushing the worn one out. This happens six times. When the sixth set wears down, usually around sixty years, the animal can no longer process the sixty to three hundred kilograms of coarse vegetation it needs each day, and it dies of starvation with everything else intact.

Herds are matriarchal: related females and their young led by the oldest, with adult males leaving around adolescence to live alone or in loose bachelor groups. Bulls enter musth, a periodic state of greatly elevated testosterone, heightened aggression and secretion from the temporal glands.

Much elephant communication is infrasonic, below about 20 hertz and therefore inaudible to us, and it travels several kilometres through air. Elephants also detect seismic vibration through the feet and trunk, and there is good evidence they use it: playback of recorded alarm calls transmitted through the ground produces appropriate responses.

The matriarch's memory has been measured rather than assumed. Groups led by older females respond more appropriately to the calls of unfamiliar elephants and to lion roars, distinguishing male from female lions by sound, and during the severe drought of the early 1990s in Tanzania the groups whose matriarchs had lived through the previous drought of the 1950s left the park for better ground and lost fewer calves.

Elephants also show consistent, unusual behaviour toward the bones of their own kind, investigating skulls and tusks with the trunk far more than other objects or other species' bones. Describing this as grief goes beyond what the data support; describing it as ordinary curiosity does not fit the specificity of it.

An Asian elephant. Only some males carry tusks, and the proportion varies by population, which has left Asian elephants less exposed to ivory poaching than their African relatives and more exposed to habitat loss and capture.
An Asian elephant. Only some males carry tusks, and the proportion varies by population, which has left Asian elephants less exposed to ivory poaching than their African relatives and more exposed to habitat loss and capture.Credit: Yathin S Krishnappa (CC BY-SA 3.0).

The Asian elephant is Endangered, with perhaps forty to fifty thousand left. Its pressures differ: less ivory poaching, because most animals have no tusks worth taking, but severe habitat fragmentation and a level of direct conflict with people that kills hundreds of humans and hundreds of elephants a year in India alone. It is also the elephant that has been captured and worked for millennia, in forestry, war and ceremony.

An African forest elephant. Its seed dispersal shapes the composition of Congo basin rainforest, and its loss measurably reduces the density of the large hardwood trees that store the most carbon.
An African forest elephant. Its seed dispersal shapes the composition of Congo basin rainforest, and its loss measurably reduces the density of the large hardwood trees that store the most carbon.Credit: Thomas Breuer (CC BY 2.5).

The forest elephant lost an estimated eighty-six per cent of its population over thirty-one years. Its ecological role is specific and hard to substitute: it disperses the seeds of large-fruited hardwoods that nothing else can swallow, and modelling published in 2019 found that removing forest elephants reduces the aboveground carbon stock of central African rainforest, because the trees that replace the elephant-dispersed species are lighter-wooded.

Traders with ivory in Central Africa in the colonial period. The trade was industrial long before the twentieth century and was entangled with the slave trade, since tusks were carried to the coast by enslaved people.
Traders with ivory in Central Africa in the colonial period. The trade was industrial long before the twentieth century and was entangled with the slave trade, since tusks were carried to the coast by enslaved people.Credit: Unknown via Fleming H. Revell Company (Public domain).

CITES banned international commercial ivory trade in 1989 after a decade in which African elephant numbers roughly halved. Poaching fell, then rose sharply again from about 2008, driven by demand in East Asia, and has since declined following China's domestic ban in 2017.

Two things remain genuinely disputed. The first is whether limited legal sales help or harm: one-off stockpile sales were permitted in 1999 and 2008, and analyses disagree about whether the 2008 sale triggered the subsequent poaching surge by signalling that ivory was tradeable again. The second is what to do with stockpiles, with some range states burning them as a statement and others arguing the value should fund conservation.

A separate and better-established finding concerns tusks themselves. During the Mozambican civil war, heavy ivory poaching in Gorongosa was followed by a sharp rise in the proportion of tuskless females, from around a fifth to more than half. Work published in 2021 identified the genetic basis as sex-linked and lethal in males, meaning the trait cannot spread freely and carries a cost in sons. This is selection by poaching, observed within a few decades.

Elephants are ecosystem engineers in the literal sense: they knock down trees, dig water holes used by other species, cut paths through dense forest and move seeds tens of kilometres. Removing them does not leave the same landscape with fewer animals in it. It changes what the landscape is.