What’s the difference between elephant and human child development?

As we celebrate the birth of the Louisville Zoo’s new elephant calf, we take a look at how human child development differs from elephants.

We love babies of all kinds at Norton Children’s. Mikki, the Louisville Zoo’s 33-year-old African elephant, gave birth Aug. 2 to a bull calf. Mikki’s pregnancy lasted 22 months (651 days). The soon-to-be named calf measured 98 cm (3 feet 2 inches) tall, 77 cm (2 feet, 5 inches) long (body, head to tail) and 198 cm (6 feet, 5 inches) from the tip of its trunk to the tip of its tail at birth. The calf weighed 275 pounds when he was two days old. The 2-month-old calf will soon have a name, through a contest presented by Norton Children’s. As we celebrate the second elephant born at the Louisville Zoo in the zoo’s 50-year history, we ask: How does child development stack up to that of an elephant?

How human babies and elephant babies are different

Let’s take a look at how human babies and elephant calves are different by the numbers.


  • 22 months: The average gestation, or pregnancy length, for an elephant
  • 200 to 250 pounds:The average weight of an elephant calf at birth
  • 3 feet:The average height of an elephant calf at birth
  • 2 to 3 pounds: Amount of weight elephant calves gain each day
  • 3 gallons:Amount of milk a calf will suckle from its mother each day
  • 4 months old: Age calves begin eating other solid foods, such as plants
  • 6 to 8 months: Age when elephant calves begin controlling their trunks to be able to use them to drink, eat, grasp and bathe
  • Almost immediately after birth:Age when elephants can stand up and walk, as they need to do so to nurse and stay close to their mother and herd

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  • 38 to 41 weeks:Average length of a human pregnancy
  • 5 pounds:Average birth weight of a newborn baby (5.5 to 10 pounds is considered in the healthy range)
  • 19 to 20 inches:Average length for a full-term baby at birth (normal range is 18 to 22 inches)
  • 7 ounces:Weight a typical newborn baby gains each day
  • 12 to 36 ounces: Amount of milk a newborn baby drinks a day (based on a child’s weight, feeding schedule, hunger)
  • 6 months old: Age most babies begin eating some solid foods
  • 7 months old: Age most babies are able to stand
  • 8 to 12 months: Age babies begin to start crawling and walking