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.
{| class="wikitable sortable"
! Mammal
! data-sort-type="number" colspan = 3 | Gestation period (days)
! Reference
|-
!
! Min
! Max
! Average
!
|-
| Aardvark (Orycteropus afer)
|
|
| style="text-align:right;" | 213
|
|-
| Anteater (Giant) (Myrmecophaga tridactyla)
| style="text-align:right;" | 170
| style="text-align:right;" | 190
| style="text-align:right;" | 180
|
|-
| Ape (Bonobo) (Pan paniscus)
| style="text-align:right;" | 196
| style="text-align:right;" | 260
| style="text-align:right;" | 228
|
|-
| Bat (Little brown) (Myotis lucifugus)
| style="text-align:right;" | 50
| style="text-align:right;" | 60
| style="text-align:right;" | 55
|
|-
| Bear (Black) (Ursus americanus)
|
|
| style="text-align:right;" | 220
|
|-
| Bear (Giant panda) (Ailuropoda melanoleuca)
| style="text-align:right;" | 95
| style="text-align:right;" | 160
| style="text-align:right;" | 127
|
|-
| Bear (Grizzly) (Ursus arctos)
|
|
| style="text-align:right;" | 215
|
|-
| Bovid (Common eland) (Taurotragus oryx)
|
|
| style="text-align:right;" | 255
|
|-
| Camelid (Bactrian camel) (Camelus bactrianus)
| style="text-align:right;" | 360
| style="text-align:right;" | 420
| style="text-align:right;" | 390
|
|-
| Camelid (Llama) (Lama glama)
|
|
| style="text-align:right;" | 330
|
|-
| Deer (Elk, aka Wapiti) (Cervus canadensis)
| style="text-align:right;" | 240
| style="text-align:right;" | 250
| style="text-align:right;" | 245
|
|-
| Elephant (African forest) (Loxodonta cyclotis)
|
|
| style="text-align:right;" | 670
|
|-
| Elephant (Asian) (Elephas maximus)
| style="text-align:right;" | 548
| style="text-align:right;" | 670
| style="text-align:right;" | 609
|
|-
| Equid (Burchell's_zebra) (Equus quagga burchelli)
|
|
| style="text-align:right;" | 390
|
|-
| Marsupial (Kangaroo) (Family Macropodidae)
|
|
| style="text-align:right;" | 42
|
|-
| Marsupial (Koala) (Phascolarctos cinereus)
|
|
| style="text-align:right;" | 34
|
|-
| Marsupial (Quokka) (Setonix brachyurus)
|
|
| style="text-align:right;" | 26
|
|-
| Marsupial (Stripe-faced dunnart) (Sminthopsis macroura)
| style="text-align:right;" | 9.5
| style="text-align:right;" | 12
| style="text-align:right;" | 11
|
|-
| Marsupial (Virginia opossum) (Didelphis virginiana)
| style="text-align:right;" | 12
| style="text-align:right;" | 13
| style="text-align:right;" | 12
|
|-
| Marsupial (Wombat) (Family Vombatidae)
| style="text-align:right;" | 26
| style="text-align:right;" | 28
| style="text-align:right;" | 27
|
|-
| Mink (European) (Mustela lutreola)
| style="text-align:right;" | 38
| style="text-align:right;" | 76
| style="text-align:right;" | 57
|
|-
| Monkey (Baboon) (Genus Papio)
|
|
| style="text-align:right;" | 185
|
|-
| Monkey (Blue) (Cercopithecus mitis)
|
|
| style="text-align:right;" | 140
|
|-
| Monkey (Squirrel) (Genus Saimiri)
|
|
| style="text-align:right;" | 167
|
|-
| Pinniped (Walrus) (Odobenus rosmarus)
|
|
| style="text-align:right;" | 456
|
|-
| Pinniped (Weddel seal) (Leptonychotes wedelli)
|
|
| style="text-align:right;" | 310
|
|-
| Rhinoceros (White) (Ceratotherium simum)
|
|
| style="text-align:right;" | 467
|
|-
| Rodent (Chinese hamster) (Cricetulus griseus)
|
|
| style="text-align:right;" | 21
|
|-
| Rodent (Red squirrel) (Sciurus vulgaris)
|
|
| style="text-align:right;" | 38
|
|-
| Sloth (Pale-throated) (Bradypus tridactylus)
|
|
| style="text-align:right;" | 183
|
|-
| Slow loris (Sunda) (Nycticebus coucang)
|
|
| style="text-align:right;" | 90
|
|-
| Whale (Bottlenose dolphin) (Tursiops truncatus)
|
|
| style="text-align:right;" | 364
|
|-
| Whale (Orca) (Orcinus orca)
| style="text-align:right;" | 473
| style="text-align:right;" | 567
| style="text-align:right;" | 532
|
|-
| Whale (Sperm) (Physeter catodon)
| style="text-align:right;" | 480
| style="text-align:right;" | 590
| style="text-align:right;" | 535
|
|-
| Whale (Spinner dolphin) (Stenella longirostris)
|
|
| style="text-align:right;" | 318
| 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.
See also
- Evolution of mammals - Timing of placental evolution
- Gestation
References
Citations
Sources
- Gestation, Incubation, and Longevity of Selected Animals
- David Crystal, The Cambridge Factfinder Cambridge: Cambridge University Press, 1998 (84).
- Online animal encyclopedia
- Study finds wide range in pregnancy length