Elephants are the largest land animals on Earth, and they're one of the most unique-looking animals, too. With their characteristic long noses, or trunks; large, floppy ears; and wide, thick legs, there is no other animal with a similar physique.

Most experts recognize two species of elephant: the Asian elephant (Elephas maximus) and the African elephant (Loxodonta africana), who live on separate continents and have many unique features. There are several subspecies that belong to one or the other of these two main species, though experts argue over how many subspecies there are and whether or not they constitute separate species, according to the San Diego Zoo.

African and Asian elephants

African elephants live in sub-Saharan Africa, the rainforests of Central and West Africa and the Sahel desert in Mali, according to National Geographic. Asian elephants live in Nepal, India and Southeast Asia in scrub forests and rainforests. [Elephant Images: The Biggest Beasts on Land]

African elephants are the larger of the two species. They grow to between 8.2 and 13 feet (2.5 and 4 meters) tall at the shoulder and weigh 5,000 to 14,000 lbs. (2,268 to 6,350 kilograms), according to National Geographic. Asian elephants are just a little smaller, growing to between 6.6 and 9.8 feet (2 and 3 m) tall at the shoulder and weighing between 4,500 and 11,000 lbs. (2,041 and 4,990 kg). In the wild, African elephants can live up to 70 years, and Asian elephants up to 60 years.

African and Asian elephants also have a few different physical features.

The ears of African elephant are larger and resemble the shape of the African continent, while Asian elephants have smaller, rounder ears, according to the San Diego Zoo.

Both male and female African elephants have large tusks and two "fingers" on the end of their trunks to help them pick items up. Asian elephants have a single "finger" on the end of their trucks. But typically, only male Asian elephants will grow large tusks, while the females and a few males have much smaller tusks called tushes that don't always grow outside the mouth.

Tusks are large, deeply rooted teeth that evolved to assist the elephant in digging, lifting, gathering food, and defense while also protecting the trunk, according to World Wildlife Fund. In the same way that humans tend to be right-handed or left-handed, elephants can be right-tusked or left-tusked. Their dominant tusk is easy to identify, because it will be more worn down than the less dominant tusk, according to the World Wildlife Fund.

Both species eat all types of vegetation, including a variety of grasses, fruits, leaves, bark and roots. They spend about about 16 hours eating, consuming anywhere from 165 to 330 lbs. (75 to 150 kg) of food per day, according to the San Diego Zoo.

An African elephant with an impressive set of tusks. (Image credit: Shutterstock)

Elephant life

Groups of elephants, or herds, follow a matriarchal structure with the eldest female in charge. Herds are composed of primarily female family members and young calves, according to the San Diego Zoo, and include 6 to 20 members depending on the food supply. When the family gets too large, herds often split into smaller groups that stay within the same area.

The matriarch relies on her experience and memory to recall where the best spots for food, water are, and where to find protection from the elements. The matriarch is also responsible for teaching the younger members of her family how to socialize with other elephants.

Elephants are very social and can communicate with one another and identify other elephants from distances of up to 2 miles using rumbling, low-pitched sounds that fall below the audible range of humans, according to the National Zoo.

Elephants readily show good manners to members within its herd and other herds, according to the San Diego Zoo. For example, they use their trunks to greet one another, either by holding it out high or by inserting the end of their trunk into another elephant's mouth.

Elephants also pay close attention to the well-being of all the members of their herd, and will do what they can to take care of and protect weak or injured members.

They're considered an extremely intelligent species, and have been observed showing advanced problem-solving skills and demonstrating empathy, mourning and self-awareness, according to an article in Scientific American.

African elephants (Loxodonta africana) at a waterhole in the Greater Kruger National Park in South Africa. (Image credit: Mark Wright/University of Hawaii Mānoa)

Next generation

Male and female elephants become sexually mature between 8 and 13 years of age. Male elephants will leave their herd around this time, as long as they're able to find their own food and protect themselves, according to the Smithsonian National Zoo. Adult males either live on their own or in small bachelor herds.

Females may not have their first calf until their middle teen years, while males may not father a calf until they are in their 30s, when they are large and strong enough to compete with other males, according to the National Zoo.

Usually, only a single calf is born following a 22-month pregnancy. A newborn calf weighs between 150 and 350 lbs. (68 and 158 kg) stands about 3 feet tall. Calves also tend to be hairy with long tails and very short trunks.

Elephant calves grow quickly, gaining 2 to 3 lbs. every day in their first year, according to the San Diego Zoo. By the time they are 2 or 3 years old, calves are ready to be weaned.

(Image credit: Chintan Mehta/Shutterstock)

Classification/Taxonomy

All elephants are mammals belonging to the elephantidae family. There are two subspecies of the African elephant: the savanna (or bush) elephant (Loxodonta africana) and the forest elephant (Loxodonta cyclotis). However, forest elephants may in fact be a distinct species of elephant instead of a subspecies, according to Cornell University.

There are three subspecies of Asian elephant: the Indian elephant (Elephas maximus indicus), the Sri Lankan elephant (Elephas maximus maximus), and the Sumatran elephant (Elephas maximus sumatranus). Another possible subspecies is Elephas maximus borneensis (Borneo pygmy elephant). The World Wildlife Fund has determined that DNA evidence suggests that the Borneo pygmy elephant is genetically different from other Asian elephants.

Conservation status

The International Union for Conservation of Nature and Natural Resources (IUCN) classifies the Asian elephant as endangered. Though it is not known exactly how many Asian elephants remain, experts believe that the population is decreasing.

The African elephant is considered vulnerable, according to the IUCN, and the species' population is increasing. According to the African Wildlife Foundation, there are around 415,000 African elephants in the wild.

Threats against the survival of both African and Asian elephants include poaching and habitat loss, according to World Wildlife Fund.

Additional resources:

Check out more interesting facts about African elephants on the Elephants for Africa website.

Learn more about elephant conservation from the International Elephant Foundation.

Meet the adorable baby elephants being cared for at Elephants Without Borders elephant orphanage in Botswana.

This article was updated on March 18, 2019, by Live Science Contributor Rachel Ross.