Taronga Zoo is expecting a baby elephant

Sydney's Taronga Zoo will hear the thump thump of little feet when expectant mother Pak Boon delivers her baby elephant after a 22-month pregnancy.

The new calf, expected this time next year, will be the fourth born as part of the zoo's conservation breeding program for Asian elephants.

Pak Boon's pregnancy was announced on Wednesday at a Thai New Year celebration, where the zoo's three female elephants were brightly painted, as they would be back home for the traditional Songkran festival.

"Pak Boon's pregnancy is a fitting opportunity to introduce zoo visitors to the cultural significance of elephants in Thailand and share Taronga's determination to support elephants, which are an endangered species," NSW Environment Minister Mark Speakman said in a statement on Wednesday.