Guests at the Dubbo zoo were the first to spot the male calf in the long grass just after dawn on Saturday, just days before World Giraffe Day on Tuesday.

Giraffe keeper Bobby-Jo Vial who was guiding the walk, said the silhouette of the calf was just visible through the mist that was hanging over the paddock.

"I knew that something had happened due to the very foggy conditions," she said.

"Giraffes coincide with the weather to give birth, such as storms or extreme weather conditions, as it helps hide the vulnerable calves from predators."

It's the seventh calf for mother Ntombi, while first-time dad Mtoto was transferred to the zoo's breeding herd in 2019 to increase the genetic diversity in the population.

Giraffe numbers have been declining in the wild in the past decade, with numbers ravaged by habitat encroachment, snares, civil unrest and poaching.

The wild population is estimated at less than 117,000, a decline of 40 per cent over 30 years.

Australian Associated Press