Animal  Number ofDays  Number of Months
Elephant (Asian) 640 – 645 22 months
Whale (Sperm) 480 – 500 16 months
(Finback) 365  
(Killer) 500  
Rhino (Black) 450 – 480 16 months
Giraffe 425 – 450 15 months
Okapi   14 months
Camel (Dromedary) 406  
(Bactrian) 410 13 months
Tapir 410  
Zebra (Grant’s) 365 12 months
Donkey 365  
Sea Lion 350 – 365  
Bottlenose Dolphin 365  
Horse 337 11 months
Llama 330  
Seal 330  
Alpaca 315 – 370  
Cow (domestic) 275 – 285 9 months
Buffalo (American) 270  
Gemsbok 270  
Otter 270 - 300  
Human 266  
Orangutan 240 - 275  
Gorilla 257 - 266  
Mandrill 250  
Eland 250 - 270  
Yak 258  
Elk 240 – 250 8.5 months
Arabian Oryx 240 - 250  
Moose 240 - 250  
Muskox 240 - 250  
Reindeer 215 - 245  
Hartebeest 214 - 242  
Chimpanzee 226 8 months
Monkeys    
Black-handed Spider 226 - 232  
Robust Black Spider Monkey 226 - 232  
Colobus Monkey 225 - 230  
Wooly Monkey 223  
Hippopotamus 225 - 250  
White handed Gibbon 210 7 months
Bear (Black) 210 - 220  
(Grizzly) 225  
(Polar) 190 - 260 (delayed implantation)  
Deer (Mule) 195 - 212  
(White-tailed) 205  
Sloth (Linne’s two-toed) 160 – 180 6 months
Baboon (Hamadrayas) 170 - 187  
Macaque (Celebes or Black Crested) 174 - 196  
Japanese 170 - 180  
Lion-tailed 165  
Monkey (Rhesus) 164  
(Squirrel) 146 – 168 5 months
(Tufted or Brown Capuchin) 149 - 158  
Lemurs    
Ring-tailed Lemur 158  
Collared 120 - 135  
Goat(domestic) 151  
Mouflon sheep 150 - 180  
Bighorn sheep 180  
Barbary sheep 160  
Markhor 135 - 170  
Sheep (domestic) 148  
Marmosets:    
Buffy tufted 170  
Goeldi 145 - 152  
Common 141 –145  
Pygmy 136  
Tamarin    
Emperor Tamarin 150  
Saddle backed Tamarin 140-150  
Golden-rumped lion 125-132  
Capybara 150  
Indian Flying Fox Bat 140-150  
Beaver 122 4 months
Pig 113  
Porcupine 112  
Hyena 110  
Chinchilla 110 - 120  
Lion 108  
Tiger 105 - 13  
Armadillo 104  
Snow Leopard 98 approx. 3 – 3 ½ months
Leopard 92 - 95  
Clouded 86 - 95  
Cheetah 93  
Puma 90  
Cougar 96  
Striped hyena 88 - 92  
Spotted Hyena 92  
Ruffed lemur 90 –102  
Binturong 90  
Cape Hunting Dog 80 2 ½ months
Guinea Pig 68  
Serval 68 - 70  
Caracal 68 - 70  
Wolf 60 – 68 2 months
Maned 67  
Red 60 - 63  
Dog 58 - 65  
Otter (Asian small-clawed) 60 - 64  
Coyote 60 - 63  
Raccoon 63  
Bobcat 60  
Cat 62  
Lynx 62  
Fox (Red) 52  
Squirrel 44 1 ½ months
Kangaroos 30 - 42  
Snowshoe Hare 36  
Rabbit 32 I month
Skunk 31  
Chipmunk 31  
Mustrat 28 - 30  
Mouse, Rat 21  
Opossum 13 less than one month

Data supplied by many contributors and compiled by Carole Precious. To submit an addition/correction, please contact us.