A giant anteater, who arrived at Yorkshire Wildlife Park from France in October, surprised staff when she gave birth to a female pup last month.
The new arrival has just been announced by the zoo, which is in Doncaster.
Keepers believe "she must have already been pregnant" when she moved, because pregnancies last six months. Their thick fur can make it difficult to detect their condition.
Animal manager Debbie Porter said: “No-one here or at her previous home was aware of the pregnancy but it was a fantastic surprise.”
“Tammy was brought to the park last year in hope that she would eventually breed with our male anteater Niki.
“The birth is fantastic and a great boost for these endangered animals."