HONG KONG -- The twin giant panda cubs born in Hong Kong in August this year have left their incubators and taken on distinctive features amid rapid growth, said Ocean Park Hong Kong on Monday.

The female cub weighed 2.7 kg, up from 122 grams at birth. The male cub grew from 112 grams at birth to 2.54 kg, said the amusement park at a press briefing.

Video footage released by the park showed that the female cub had strong limbs, and often crawled in its crib squeaking loudly.

The shapes of the black patches around their eyes help tell the twins apart -- round for the male cub and tilted upwards at the outer end for the female, according to Elke Wu, assistant curator of zoological operations at the park, adding that the cubs might soon outgrow these features.

The cubs have been weaning off their mother Ying Ying since they were a week old and shifting to baby formula made by caretakers. They have three meals a day at eight-hour intervals.

As the oldest first-time giant panda mother on record, Ying Ying suffered a loss of appetite due to exhaustion from childbirth. Caretakers have adjusted its diet to help it recover.

"Now Ying Ying has recovered 70 percent to 80 percent of its food consumption volume prior to childbirth. The caretakers will closely monitor its conditions because it is still very sensitive to changes in the surroundings," said Wu.

The park has been working with two keepers from the China Conservation and Research Center for Giant Panda based in Southwest China's Sichuan province to ensure the successful birth and upbringing of the cubs.

Dong Li, a keeper with the center, said Ying Ying had good maternal instincts because it always got up to tend to the cubs whenever they moved.

The twins are expected to meet the public when they are six months old, and they will live with Ying Ying until they are two or three years old, said Howard Chuk, head of zoological operations and conservation at the park.