Most animals are pregnant for quite a short period of time. In comparison to a cat, for example, humans are pregnant for an incredibly long time. So what animal has the longest pregnancy period, and why? Let's dive in!

Human pregnancy periods might be rather lengthy, but perhaps surprisingly, aren't even close to the longest pregnancy on Earth.

Indeed, at only an average of nine months, human pregnancy lasts less than half the length of one particular animal's impressive gestation.

What animal holds the record for the longest pregnancy in the animal kingdom, and how long does this period last? TAG24 takes a look at some of the most lengthy gestation periods out there.

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Let's baby bump along!

The animal that has the longest pregnancy in the world is the African elephant, which remains pregnant for more than twice the length of the average human.

Part of the reason for this lengthiness is the pure size of the offspring that needs to develop, but also the need for calves to come out fully developed and ready for life in the wild.

These giant mammals are native to a number of different countries in southern, western, central, and eastern Africa. They are some of the smartest animals in the world, and also one of the most endangered. For years, they have been poached for the ivory in their tusks, and this rapid decline in population becomes even more upsetting when you consider that elephants mourn their dead.

Elephants generally have a gestation period of around 22 months, averaging 645 days of pregnancy. This makes them by-far the animal with the longest and most impressive pregnancy in the world and, for contrast, this is almost three times the length of the average human pregnancy (around 260-280 days).

Here are some of the animals with longest pregnancies in the world:

• Rhino (15 to 18 months)
• Giraffe (14 to 15 months)
• Camel (12 to 14 months)
• Horse (11 to 13 months)
• Seal (8 to 15 months)
• Two-fingered sloth (8 to 9 months)
• Moose (8 months)
• Hippopotamus (8 months)

There are a variety of sharks and whales that also have seriously long gestation periods, but if we had included them, they would have made up the majority of this list.

Scientists believe that elephants are pregnant for so long because this allows their offspring time to grow a fully-developed brain, be born with complex cognitive skills, and have immediate survival instincts. This is an evolutionary technique to help keep the calf alive while it's still developing both inside the womb and out in the wild.

When a baby elephant is born, it can already interact with the herd, can move around, and has a good understanding of its environment. This gives it more of a chance to survive in the harsh environment that elephants call home.

Baby elephants for the win!