Samba arrived at the zoo on 16 March after being transferred from Jimmy’s Farm and Wildlife Park in Suffolk, but escaped the following day along with her sister Tango.
While Tango was quickly found nearby, Samba, described as the “more adventurous” of the pair, could not be located.
In an update issued on Thursday, Marwell Wildlife said: “Our teams remain fully committed and continue to carry out extensive searches both day and night.
“We are still using specialist tracking dogs, thermal drone technology, and camera traps in key areas where Samba is most likely to travel, particularly along waterways and dense vegetation.
“While this is a challenging search due to the size of the area and Samba’s natural instincts to stay hidden, we are not giving up and remain focused on bringing her home safely.”