News Animals National Zoo Reveals Panda Cub is a Boy Tiny cub appears to be healthy and strong. By Mary Jo DiLonardo Mary Jo DiLonardo LinkedIn Twitter Senior Writer University of Cincinnati Mary Jo DiLonardo has worked in print, online, and broadcast journalism for 25 years and covers nature, health, science, and animals. Learn about our editorial process Published October 6, 2020 12:40PM EDT The panda cub weighs 3.6 pounds. Smithsonian National Zoo Share Twitter Pinterest Email News Environment Business & Policy Science Animals Home & Design Current Events Treehugger Voices It's a boy! The Smithsonian National Zoo's 6-week-old giant panda cub is male, zoo scientists have confirmed. During the tiny bear's first veterinary exam in mid-September, veterinarians took a swab from his cheek for DNA analysis. Because male and female cubs appear similar at birth, genetic tests are the most accurate way to determine a newborn panda's sex. Scientists tested the sample and confirmed that the cub is male. They announced the results to keepers and fans online with a gender reveal ceremony, using a painting created by the cub's father, giant panda Tian Tian (tee-YEN tee-YEN). Zoo veterinarians report that the cub seems to be strong and healthy. They examined him again briefly on Oct. 1 and found he was 3.6 pounds and measured 14 inches from his nose to the tip of his tail. He measured 12.5 inches around his abdomen. Both of the cub's eyes are beginning to open. Keepers say they are encouraged by his progress. At 22 years old, the cub's mother, Mei Xiang (may-SHONG), is the oldest giant panda in the U.S. and the second oldest giant panda documented globally to give birth, according to the zoo. Reproductive scientists from the Smithsonian Conservation Biology Institute (SCBI) and zoo veterinarians performed an artificial insemination using frozen semen from 23-year-old Tian Tian. This is the first time a U.S. zoo has had a successful panda pregnancy and birth via artificial insemination using only frozen semen, the zoo reports. Located in Washington, D.C., the zoo's panda habitat is currently closed to provide privacy for Mei Xiang and her cub. But panda fans can watch them via the giant panda cam on the zoo’s website. In addition to this new cub, Mei Xiang has given birth to three surviving offspring that are living in China. As part of the National Zoo's cooperative breeding agreement with the China Wildlife Conservation Association, all cubs born at the zoo move to China when they are 4 years old. The agreement expires in December 2020.