PORTLAND -- The Oregon Zoo’s Asian elephant calf Samudra celebrated his two-month birthday Thursday, and biologists say he is happy, healthy and making great strides.

 Slideshow: Samudra plays with pumpkin

Sam weighed in at 467 pounds Wednesday, up more than 180 pounds from his birth weight, according to zoo elephant keeper Bob Lee. He even has new teeth coming in, which Lee calls "milk teeth" and that resemble little corn kernels in his mouth.

"We couldn't be happier about the way Sam's progressing," Lee said. "He's growing and learning and interacting well with all the females in the herd. It warms the heart to see Sam and Rose-Tu together, especially after all they've been through."

Sam was born Aug. 23 at the zoo and his mother, in confusion, almost trampled him to death. Zoo keepers were able to rescue the new-born elephant.

Rose-Tu was the last elephant born at the zoo prior to Sam. She had never seen a birth before and zoo keepers believe it frightened her. Biologists worked to reintroduce the new-born to its mother in the last two months, noting that human-reared elephants have a “low success rate.”

"It took a while," Lee said, "But now Rose-Tu is a loving and protective mother to Sam." 

The zoo has been working ever since to introduce Sam to other elephants in the herd.

Asian elephants are an endangered species. More than 25 have been born at the Oregon Zoo since the 1960s. Sam is the first third-generation elephant to be born in the United States, according to zoo keepers.