It's officially double hump day after the Detroit Zoo in Royal Oak announced Wednesday the birth of a 125-pound camel calf.

The Bactrian camel calf, Rusi, was born July 31, 2017, officials said. Her parents are Rusty and Suren, both 9.

“Rusi is finding her footing and is curious about her new surroundings," Scott Carter, the Detroit Zoological Society's chief life sciences officer, said. "Like most newborns, she spends a lot of time napping and nursing.”

“Suren is an attentive mother and is keeping a close eye on her new little one.”

Rusi stands about 4-feet-tall. She joins her 3-year-old brother Humphrey in the family, officials said in a statement Wednesday.

Visitors to the zoo can catch a glimpse of Rusi at the camel habitat across from the Horace H. Rackham Memorial Fountain.

Rusi's coat is soft and gray but will grow thick, coarse and sandy brown.

Her hump, which consists mostly of skin and hair, is limp but will become more defined as she reaches 6-months in age. Contrary to popular belief, camels store fat in their humps, not water. The fat provides energy when food is limited.

Bactrian camels have two humps while dromedary camels have one. Bactrian camels also stand about 7-feet-tall at the humps and weigh up to 1,600 pounds when they reach maturity at about age 4.

They can also survive in temperatures ranging from minus 20 degrees to 122 degrees.

The animals are critically endangered, numbering fewer than a thousand in Central and East Asia.

cramirez@detroitnews.com