WASHINGTON, Aug. 26 (UPI) -- The Smithsonian's National Zoo announced Wednesday the smaller of its twin giant panda cubs has died after being rejected by its mother.
"We are sad to announce that the smaller of the two panda cubs has died," the zoo said in a Facebook post Wednesday.
"The panda team continues to monitor Mei Xiang and the larger cub. They are encouraged that this cub appears to be strong and behaving normally," the post said.
Officials said the mother panda seemed to prefer the larger of the twins and would refuse attempts to swap out the cubs to give them equal time with their mother.
The zoo said keepers were concerned about the smaller cub's fluctuating weight, as rapid weight changes are unusual after the first 48 hours of the cub's life.
The National Zoo's panda team is receiving help from Asia Trail keepers, additional veterinarians and a panda keeper from Zoo Atlanta.
"The entire Zoo community appreciates the outpouring of well-wishes from around the world," the zoo said.