(CNN) -- Mara had been putting on weight lately, so those around her thought something was up. But she was on birth control, so if there was to be a baby, that would be a bit of a surprise.
Mara the hippopotamus is now the proud and doting mother of a healthy calf.
The baby doesn't have a name yet. The staff at the Los Angeles Zoo hasn't been able to get close enough to determine the sex of the newborn.
According to a release from the zoo, Mara went into labor Friday while in her outdoor pool but chose to gave birth on dry land. Animal care staff was close by but all went well.
Mom, child and father, known as Adhama, can be viewed by zoo visitors each day.
This is the first baby hippo at the zoo in 26 years. The staff had guessed that Mara was pregnant but only had limited testing options.
Mara, 10, came to Los Angeles from Topeka, Kansas, in December and instantly bonded with Adhama, who is 3 years old, zoo officials said.
CNN's Amanda Watts contributed to this report.