Below are the average gestation length of many animal species or groups in order from most to least.
All gestation lengths are given on a day basis.
- Asian Elephant: 616
- Sperm Whale: 530
- Black Rhino: 450
- Giraffe: 435
- Camel: 390
- Zebra: 375
- Donkey: 365
- Alpaca: 355
- Sea Lion: 350
- Domestic Horse: 335
- Llama: 330
- Monk Seal: 330
- Cow: 285
- Human: 270*
- Gorilla: 257
- Elk: 245
- Polar Bear: 241
- Chimpanzee: 240
- Hippopotamus: 235
- Black Bear: 220
- American Bison: 217
- Brown Bear: 215
- White-tailed Deer: 201
- Baboon: 187
- Rhesus Monkey: 164
- Domestic Goat: 150
- Domestic Sheep: 147
- Domestic Pig: 114
- Hedgehog: 112
- Chinchilla: 110
- Lion: 108
- Tiger: 107
- Leopard: 94
- Puma: 90
- Otter: 75
- Ginepig: 65
- Mink: 55
- Wild Wolf: 65
- Domestic Cat: 64
- Raccoon: 63
- Domestic Dog: 61
- Red Fox: 52
- European Mink: 50
- Kangaroo: 42
- Mustela Altaica: 41
- Grey Squirrel: 35
- Domestic Rabbit: 32
- Squirrel: 31
- Muskrat: 29
- Wombat: 27
- Gerbil: 23
- Rat: 22
- Meadow Mouse: 21
- Domestic Mouse: 19
- Hamster: 18
- Opossum: 12
It is possible to extend the list. However, the gestation length of popular animal species are around these numbers. Of course, these are average numbers and there may be some deviations. But you can use it as a reference.
* The gestation period for humans is technically 280 days. However, studies show that only 4% of human females give birth in 280 days. In fact, only 70% of all pregnancies occur between 270-290 days. Mostly, pregnancy lasts around 270 days.