# List of mammalian gestation durations

This is a collection of lists of mammal gestation period estimated by experts in their fields. The mammals included are only viviparous (marsupials and placentals) as some mammals, which are monotremes (including platypuses and echidnas) lay their eggs. A marsupial has a short gestation period, typically shorter than placental. For more information on how these estimates were ascertained, see Wikipedia's articles on gestational age.
The gestation figures given here are shown in days. They represent average values and should only be considered as approximations.
| Mammal | Gestation period (days) | Gestation period (days) | Gestation period (days) |
| | Min | Max | Average |
| Aardvark (Orycteropus afer) | | | 213 |
| Anteater (Giant) (Myrmecophaga tridactyla) | 170 | 190 | 180 |
| Ape (Bonobo) (Pan paniscus) | 196 | 260 | 228 |
| Ape (Bornean orangutan) (Pongo pygmaeus) | | | 234 |
| Ape (Chimpanzee) (Pan troglodytes) | 230 | 250 | 240 |
| Ape (Gorilla) (Genus Gorilla) | 255 | 260 | 257 |
| Ape (Human) (Homo sapiens) | 259 | 275 | 270 |
| Ape (Lar gibbon) (Hylobates lar) | | | 220 |
| Ape (Siamang) (Symphalangus syndactylus) | | | 236 |
| Armadillo (Nine-banded) (Dasypus novemcinctus) | | | 120 |
| Armadillo (Six-banded) (Euphractus sexcinctus) | | | 62 |
| Badger (American) (Taxidea taxus) | | | 60 |
| Bat (Common vampire) (Desmodus rotundus) | | | 213 |
| Bat (Little brown) (Myotis lucifugus) | 50 | 60 | 55 |
| Bear (Black) (Ursus americanus) | | | 220 |
| Bear (Giant panda) (Ailuropoda melanoleuca) | 95 | 160 | 127 |
| Bear (Grizzly) (Ursus arctos) | | | 215 |
| Bear (Polar) (Ursus maritimus) | | | 241 |
| Bovid (American bison) (Bison bison) | | | 285 |
| Bovid (Barbary sheep) (Ammotragus lervia) | | | 158 |
| Bovid (Bay duiker) (Cephalophus dorsalis) | | | 120 |
| Bovid (Bighorn sheep) (Ovis canadensis) | | | 180 |
| Bovid (Blackbuck) (Antilope cervicapra) | | | 165 |
| Bovid (Cattle) (Bos taurus) | 279 | 287 | 283 |
| Bovid (Common eland) (Taurotragus oryx) | | | 255 |
| Bovid (Domestic goat) (Capra hircus) | 145 | 155 | 150 |
| Bovid (Domestic sheep) (Ovis aries) | | | 150 |
| Bovid (Domestic yak) (Bos grunniens) | | | 255 |
| Bovid (Dorcas gazelle) (Gazella dorcas) | | | 132 |
| Bovid (Impala) (Aepyceros melampus) | | | 191 |
| Bovid (Mountain goat) (Oreamnos americanus) | | | 176 |
| Bovid (Sable antelope) (Hippotragus niger) | | | 270 |
| Bovid (Thomson's gazelle) (Gazella thomsonii) | | | 165 |
| Bovid (Zebu) (Bos indicus) | | | 280 |
| Camelid (Alpaca) (Lama pacos) | | | 345 |
| Camelid (Bactrian camel) (Camelus bactrianus) | 360 | 420 | 390 |
| Camelid (Llama) (Lama glama) | | | 330 |
| Canid (African wild dog) (Lycaon pictus) | | | 71 |
| Canid (Bat-eared fox) (Otocyon megalotis) | | | 65 |
| Canid (Coyote) (Canis latrans) | | | 62 |
| Canid (Domestic dog) (Canis familiaris) | 58 | 65 | 61 |
| Canid (Golden jackal) (Canis aureus) | | | 62 |
| Canid (Island fox) (Urocyon littoralis) | | | 63 |
| Canid (Red fox) (Vulpes vulpes) | | | 52 |
| Canid (Wolf) (Canis lupus) | 60 | 68 | 64 |
| Cat (Canadian lynx) (Lynx canadensis) | | | 60 |
| Cat (Cheetah) (Acinoyx jubatus) | | | 92 |
| Cat (Domestic) (Felis catus) | 58 | 67 | 64 |
| Cat (Leopard) (Panthera pardus) | 92 | 95 | 93 |
| Cat (Lion) (Panthera leo) | | | 108 |
| Cat (Puma) (Puma concolor) | | | 90 |
| Cat (Tiger) (Panthera tigris) | 105 | 113 | 109 |
| Deer (Chital) (Axis axis) | | | 218 |
| Deer (Common fallow) (Dama dama) | | | 228 |
| Deer (Elk, aka Wapiti) (Cervus canadensis) | 240 | 250 | 245 |
| Deer (Moose) (Alces alces) | 240 | 250 | 245 |
| Deer (Mule) (Odocoileus hemionus) | | | 206 |
| Deer (Père David's) (Elaphurus davidianus) | | | 284 |
| Deer (Red) (Cervus elaphus) | | | 238 |
| Deer (Reindeer) (Rangifer tarandus) | | | 215 |
| Deer (Sambar) (Rusa unicolor) | | | 246 |
| Deer (White-tailed) (Odocoileus virginianus) | | | 201 |
| Elephant shrew (Bushveld) (Elephantulus intufi) | | | 51 |
| Elephant shrew (Eastern rock) (Elephantulus myurus) | | | 46 |
| Elephant (African bush) (Loxodonta africana) | | | 670 |
| Elephant (African forest) (Loxodonta cyclotis) | | | 670 |
| Elephant (Asian) (Elephas maximus) | 548 | 670 | 609 |
| Equid (Burchell's_zebra) (Equus quagga burchelli) | | | 390 |
| Equid (Donkey) (Equus asinus) | 335 | 426 | 365 |
| Equid (Grant's zebra) (Equus quagga boehmi) | 361 | 390 | 375 |
| Equid (Horse) (Equus caballus) | 330 | 342 | 336 |
| Ferret (Domestic) (Mustela furo) | 41 | 42 | 41 |
| Galago (Family Galagidae) | | | 124 |
| Giraffe (Genus Giraffa) | 420 | 450 | 430 |
| Hare (European) (Lepus europaeus) | | | 41 |
| Hedgehog (European) (Erinaceus europaeus) | | | 34 |
| Hippopotamus (Common) (Hippopotamus amphibius) | 225 | 250 | 237 |
| Hyena (Striped) (Hyaena hyaena) | | | 90 |
| Hyrax (Rock) (Procavia capensis) | | | 255 |
| Kinkajou (Potos flavus) | | | 77 |
| Lemur (Superfamily Lemuroidea) | | | 128 |
| Manatee (West Indian) (Trichechus manatus) | 365 | 426 | 396 |
| Marsupial (Kangaroo) (Family Macropodidae) | | | 42 |
| Marsupial (Koala) (Phascolarctos cinereus) | | | 34 |
| Marsupial (Quokka) (Setonix brachyurus) | | | 26 |
| Marsupial (Stripe-faced dunnart) (Sminthopsis macroura) | 9.5 | 12 | 11 |
| Marsupial (Virginia opossum) (Didelphis virginiana) | 12 | 13 | 12 |
| Marsupial (Wombat) (Family Vombatidae) | 26 | 28 | 27 |
| Mink (European) (Mustela lutreola) | 38 | 76 | 57 |
| Monkey (Baboon) (Genus Papio) | | | 185 |
| Monkey (Blue) (Cercopithecus mitis) | | | 140 |
| Monkey (Bonnet macaque) (Macaca radiata) | 153 | 169 | 161 |
| Monkey (Brown woolly) (Lagothrix lagothrica) | | | 139 |
| Monkey (Celebes crested macaque) (Macaca nigra) | 155 | 175 | 164 |
| Monkey (Crab-eating macaque) (Macaca fascicularis) | 153 | 179 | 165 |
| Monkey (Dusky leaf) (Trachypithecus obscurus or Presbytis obscurus) | | | 150 |
| Monkey (Formosan rock macaque) (Macaca cyclopis) | | | 163 |
| Monkey (Gelada) (Theropithecus gelada) | | | 170 |
| Monkey (Goeldi's marmoset) (Callimico goeldii) | 149 | 152 | 151 |
| Monkey (Golden lion tamarin) (Leontopithecus rosalia) | | | 131 |
| Monkey (Gracile capuchin) (Genus Cebus) | | | 180 |
| Monkey (Grey-cheeked mangabey) (Cercocebus albigena) | | | 174 |
| Monkey (Grivet) (Cercopithecus aethiops) | | | 210 |
| Monkey (Guenon) (Genus Cercopithecus) | | | 160 |
| Monkey (Japanese macaque) (Macaca fuscata) | 150 | 180 | 166 |
| Monkey (King colobus) (Colobus polykomos) | 180 | 213 | 202 |
| Monkey (Mantled howler) (Alquatta paliatta) | | | 139 |
| Monkey (Northern plains gray langur) (Semnopithecus entellus or Presbytis entellus) | | | 183 |
| Monkey (Patas) (Erythrocebus patas) | | | 192 |
| Monkey (Proboscis) (Nasalis larvatus) | | | 166 |
| Monkey (Red-shanked douc) (Pygathrix nemaeus) | 180 | 190 | 185 |
| Monkey (Red-tailed) (Cercopithecus ascanius) | | | 190 |
| Monkey (Rhesus macaque) (Macaca mulatta) | | | 164 |
| Monkey (Southern pig-tailed macaque) (Macaca nemestrina) | 168 | 171 | 170 |
| Monkey (Spider) (Genus Ateles) | | | 139 |
| Monkey (Squirrel) (Genus Saimiri) | | | 167 |
| Monkey (Stump-tailed macaque) (Macaca arctoides) | 168 | 184 | 182 |
| Monkey (Talapoin) (Cercopithecus talapoin) | | | 196 |
| Monkey (Tamarin) (Genus Saguinus) | | | 162 |
| Monkey (Toque macaque) (Macaca sinica) | | | 180 |
| Monkey (Vervet) (Cercopithecus pygerythrus) | | | 195 |
| Otter (Subfamily Lutrinae) | 60 | 86 | 73 |
| Pig (Domestic) (Sus domesticus) | 112 | 115 | 113 |
| Pig (Wild boar) (Sus scrofa) | | | 120 |
| Pinniped (California sea lion) (Zalophus californianus) | | | 350 |
| Pinniped (Northern fur seal) (Callorhinus ursinus) | | | 254 |
| Pinniped (Southern elephant seal) (Mirounga leonina) | | | 335 |
| Pinniped (Walrus) (Odobenus rosmarus) | | | 456 |
| Pinniped (Weddel seal) (Leptonychotes wedelli) | | | 310 |
| Pronghorn (Antilocapra americana) | | | 246 |
| Rabbit (Domestic) (Oryctolagus cuniculus domesticus) | 28 | 35 | 31 |
| Raccoon (Common) (Procyon lotor) | | | 63 |
| Rhinoceros (Black) (Diceros bicornis) | | | 450 |
| Rhinoceros (Indian) (Rhinoceros unicornis) | | | 478 |
| Rhinoceros (White) (Ceratotherium simum) | | | 467 |
| Rodent (Beaver) (Genus Castor) | | | 122 |
| Rodent (Chinchilla) (Genus Chinchilla) | 105 | 115 | 110 |
| Rodent (Chinese hamster) (Cricetulus griseus) | | | 21 |
| Rodent (Chipmunk) (Subtribe Tamiina) | | | 31 |
| Rodent (Cotton mouse) (Peromyscus gossypinus) | | | 23 |
| Rodent (Coypu) (Myocastor coypus) | | | 132 |
| Rodent (Crested porcupine) (Hystrix cristata) | | | 112 |
| Rodent (Domestic guinea pig) (Cavia porcellus) | 56 | 74 | 65 |
| Rodent (Domestic mouse) (Mus musculus) | | | 19 |
| Rodent (Eastern gray squirrel) (Sciurus carolinensis) | 30 | 40 | 35 |
| Rodent (Golden hamster) (Mesocricetus auratus) | | | 16 |
| Rodent (Greater Egyptian gerbil) (Gebrillus pyramidum) | | | 21 |
| Rodent (Green acouchi) (Myoprocta pratti) | | | 98 |
| Rodent (Hamster) (Subfamily Cricetinae) | 16 | 23 | 20 |
| Rodent (Hispid cotton rat) (Sigmodon hispidus) | | | 27 |
| Rodent (Meadow mouse) (Microtus pennsylvanicus) | | | 21 |
| Rodent (Mongolian gerbil) (Meriones unguiculatus) | 22 | 130 | 24 |
| Rodent (Muskrat) (Ondatra zibethicus) | 28 | 30 | 29 |
| Rodent (North American porcupine) (Erethizon dorsatum) | | | 113 |
| Rodent (Rat) (Genus Rattus) | 21 | 23 | 22 |
| Rodent (Red squirrel) (Sciurus vulgaris) | | | 38 |
| Rodent (Southern flying squirrel) (Glaucomys volans) | | | 40 |
| Rodent (White-footed mouse) (Peromyscus leucopus) | | | 23 |
| Skunk (Striped) (Mephitis mephitis) | | | 65 |
| Sloth (Hoffmann's two-toed)) (Choloepus hoffmanni) | 355 | 377 | 366 |
| Sloth (Pale-throated) (Bradypus tridactylus) | | | 183 |
| Slow loris (Sunda) (Nycticebus coucang) | | | 90 |
| Tapir (Malayan) (Acrocodia indica) | | | 379 |
| Treeshrew (Common) (Tupaia glis) | | | 46 |
| Whale (Beluga) (Delphinapterus leucas) | | | 408 |
| Whale (Blue) (Balaenoptera musculus) | 305 | 365 | 335 |
| Whale (Bottlenose dolphin) (Tursiops truncatus) | | | 364 |
| Whale (Harbour porpoise) (Phocoena phocoena) | | | 270 |
| Whale (Northern right whale dolphin) (Lissodelphis borealis) | 368 | 374 | 371 |
| Whale (Orca) (Orcinus orca) | 473 | 567 | 532 |
| Whale (Sperm) (Physeter catodon) | 480 | 590 | 535 |
| Whale (Spinner dolphin) (Stenella longirostris) | | | 318 |

## Factors affecting the gestation period in mammals

There are several factors affecting the length of the gestation period in mammals.

### Animal size/mass

There is a positive relationship between mass at birth and length of gestation in eutherian mammals. Larger mammals are more likely to produce a well-developed neonate than small mammals. Large mammals develop at an absolute slower rate compared to small mammals. Thus, the large mammal tend have longer gestation periods than small mammal as they tend to produce larger neonate. Large mammals require a longer period of time to attain any proportion of adult mass compared to small mammals.

### The level of development at birth

More developed infants will typically require a longer gestation period. Altricial mammals needs less time to gestate compare to the precocial (well-developed neonate) mammal. A typical precocial mammal has a gestation period almost four times longer than a typical altricial mammal of the same body size. Precocial mammal species generally have greater adult body weights than altricial mammals as precocial mammals have markedly longer gestation periods than altricial mammals. The neonatal of larger mammals develop relatively more quickly and thus making it more likely that a large mammal would produce a more well-developed neonate as a consequence of its longer gestation period. In some cases, some mammal species may have similar gestation periods despite having significantly different body masses.

### Environmental factor

In response to the conditions of the environment, some mammals, such as bat delay the implantation due to the cold temperature in winter. Another factor is due to the shortage of food stocks during winter as the insects are being driven away and as the result, bat hibernate in pregnant condition.
In pinnipeds, the purpose of delayed implantation is in order to increase survival chance of the young animals as the mother ensure that the neonates are born at an optimal season.