Gestational times for
different animals

The BRAIN magazine

A dolphin underwater looking at the viewer

The average time it takes for a placental or marsupial baby to develop in the mother’s uterus is linked to the size of the animal.

Compared with placental animals, marsupial babies are born underdeveloped as they migrate to a pouch to develop.

A yawning baby wearing a grey knit hat with ears. It is tucked in to a bed and has a white teddy bear tucked in next to it.

Photo by Minnie Zhou on Unsplash

A baby elephant with its front legs resting on another baby elephant that is lying down. The legs of older elephants are visible behind it.

Image: sdbower / Adobe Stock

A pod of adult and baby sperm whales swimming near the surface of the ocean.

Image: Stanislav / Adobe Stock

The heads of two giraffes. One is locking the other's cheek.

Image: David_Steele / Adobe Stock

The heads of two horses looking down so that their noses are pointing directly at the viewer.
A dolphin underwater looking at the viewer
A mother and baby chimpanzee in a tree. The mother is scratching the chin of the baby, who has its hands on a tree branch and the mother's face.
An adult grizzly bear sitting on grass. Two grizzly bear cubs are climbing the adult.
Five sheep standing in front of several short trees and a dirt field. The sheep are looking at the viewer
A small lion cub ready to pounce. The cub is on grass under a tree.
A yellow labrador puppy with its front leg resting on the shoulder of a cat, which is laying in front of the labrador.
A ginger and white guinea pig standing on its hind legs holding a carrot upright with one of its front legs. Whole carrots, including their green tops, are lying on the grass behind the guinea pig.
A kangaroo joey hanging out of its mother's pouch.
A young wombat sitting down on a small grassy mound
A baby white rabbit with blue eyes and fuzzy, fluffy fur
A mouse sticking its head out of a hole in a woven straw mat
A yawning baby wearing a grey knit hat with ears. It is tucked in to a bed and has a white teddy bear tucked in next to it.

Photo by Minnie Zhou on Unsplash

A baby elephant with its front legs resting on another baby elephant that is lying down. The legs of older elephants are visible behind it.

Image: sdbower / Adobe Stock

A pod of adult and baby sperm whales swimming near the surface of the ocean.

Image: Stanislav / Adobe Stock

The heads of two giraffes. One is locking the other's cheek.

Image: David_Steele / Adobe Stock

The heads of two horses looking down so that their noses are pointing directly at the viewer.
A dolphin underwater looking at the viewer
A mother and baby chimpanzee in a tree. The mother is scratching the chin of the baby, who has its hands on a tree branch and the mother's face.
An adult grizzly bear sitting on grass. Two grizzly bear cubs are climbing the adult.
Five sheep standing in front of several short trees and a dirt field. The sheep are looking at the viewer
A small lion cub ready to pounce. The cub is on grass under a tree.
A yellow labrador puppy with its front leg resting on the shoulder of a cat, which is laying in front of the labrador.
A ginger and white guinea pig standing on its hind legs holding a carrot upright with one of its front legs. Whole carrots, including their green tops, are lying on the grass behind the guinea pig.
A kangaroo joey hanging out of its mother's pouch.
A young wombat sitting down on a small grassy mound
A baby white rabbit with blue eyes and fuzzy, fluffy fur
A mouse sticking its head out of a hole in a woven straw mat

Human – 270 days

Elephant – 640 days

Sperm whale – 535 days

Giraffe – 430 days

Horse – 336 days

Dolphin – 318 days

Chimpanzee – 240 days

Grizzly bear – 215 days

Sheep – 148 days

Lion – 108 days

Dogs and cats – 60 days

Guinea pig – 65 days

Kangaroo – 42 days

Wombat – 27 days

Rabbit – 33 days

Mouse – 20 days