Wild Animal Gestation Chart
The African elephant has the longest gestation of any land mammal at about 645 days, close to 22 months. At the other extreme the Virginia opossum gives birth after just 13 days. Between them sit sperm whales at 530 days, giraffes at 430, humans at 280, lions at 110 and red kangaroos at 33.
| Species | Average days | Range | Months | Young |
|---|---|---|---|---|
| Virginia opossum | 13 | 12–14 | 0.4 months | 8-9 joeys |
| Red kangaroo | 33 | 30–36 | 1.1 months | 1 joey |
| Grey squirrel | 44 | 40–45 | 1.4 months | 2-4 kits |
| Red fox | 52 | 49–55 | 1.7 months | 4-6 kits |
| Tiger | 105 | 93–112 | 3.4 months | 2-4 cubs |
| Lion | 110 | 105–115 | 3.6 months | 2-4 cubs |
| White-tailed deer | 200 | 187–222 | 6.6 months | 1-2 fawns |
| Grizzly bear | 235 | 180–250 | 7.7 months | 1-3 cubs |
| Chimpanzee | 237 | 230–240 | 7.8 months | 1 infant |
| Hippopotamus | 240 | 225–250 | 7.9 months | 1 calf |
| Gorilla | 257 | 250–270 | 8.4 months | 1 infant |
| Human | 280 | 259–294 | 9.2 months | 1 baby |
| Blue whale | 340 | 330–360 | 11.2 months | 1 calf |
| Dolphin | 365 | 340–380 | 12.0 months | 1 calf |
| Zebra | 375 | 360–390 | 12.3 months | 1 foal |
| Manatee | 380 | 365–400 | 12.5 months | 1 calf |
| Giraffe | 430 | 400–460 | 14.1 months | 1 calf |
| Walrus | 460 | 450–480 | 15.1 months | 1 calf |
| White rhinoceros | 490 | 480–500 | 16.1 months | 1 calf |
| Sperm whale | 530 | 480–590 | 17.4 months | 1 calf |
| Asian elephant | 617 | 600–640 | 20.3 months | 1 calf |
| African elephant | 645 | 640–660 | 21.2 months | 1 calf |
What these animals have in common
Across wild mammals gestation length tracks two things: adult body size and how developed the young must be at birth. Large grazing and browsing animals on open ground, such as elephants, giraffes and zebras, produce a single calf that can walk within an hour, and that demands a very long pregnancy. Marine mammals face the same pressure because a calf must swim and surface to breathe immediately. Predators like lions, tigers and foxes can hide helpless young in a den, so their pregnancies are short and their litters larger. Marsupials take the strategy to its limit: a kangaroo or opossum is born after a few weeks as a barely formed embryo and completes development in the pouch. Bears add a further twist through delayed implantation, where a fertilised egg pauses for months before development begins, which makes their apparent gestation far longer than the real one.
Species pages in this group
Frequently asked questions
Figures are averages from published data. Individual animals vary, and results are for planning rather than veterinary advice.