We can’t get enough of the Giant Panda cubs at the Toronto Zoo! They recently reached another milestone. Not only did they turn eight-weeks-old, but their eyes are now partially open! They are sensitive to both light and dark, but do not have any resolution yet.

Not only are their eyes opening, but their vocalizations are becoming stronger each day, developing from what once was a quiet squeak to what can now be described as a stronger squawk!

Photo Credits: Toronto Zoo

 Both cubs continue to grow, with their last weights both being over 2,000 grams (4.4 lbs.), and they average 48 cm (18.9 in.) in length from the tip of their head to tip of the tail!

This is still a very critical time for these cubs. Mom, Er Shun, and her cubs will remain in the maternity den, which is not viewable to the public. However, Er Shun periodically has access to her day room to promote exercise and to give her a chance to eat her bamboo.

Although Er Shun and the cubs are not on exhibit, and media are not permitted in the maternity area of the Giant Panda Exhibit, Toronto Zoo staff will continue to provide updates, photos and video as they become available.

It all started on October 13th when the Toronto Zoo announced the birth of the two Giant Panda cubs. ZooBorns shared the initial birth announcement, and we have been sharing updates as released by the Zoo.

The Toronto Zoo has stated that Er Shun and her twin cubs would be living within the private maternity area, inside the Giant Panda House, for approximately four to five months.

Giant Panda mothers are known for only looking after one cub at a time, so keepers are helping raise the twins using a method called ‘twin swapping’. One baby is left with the mother, and the keepers switch the twins every few hours, so each one gets care and milk directly from mom. Since the beginning, Er Shun has been demonstrating excellent maternal instincts, and she began cleaning and cradling the first cub soon after its birth.

As the maternity area of the Giant Panda House is not visible to the public, Toronto Zoo staff have been providing regular updates on the progress of the cubs, via the zoo’s website and social media: http://www.torontozoo.com/GiantPandaCubs/

The Giant Panda (Ailuropoda melanoleuca) is native to only a few mountain ranges in central China, usually at elevations between 5,000 – 10,000 feet. In these cool, misty forests, Giant Pandas forage for bamboo, which comprises 99% of their diet, about 10 to 16 hours a day.

Giant Pandas reach sexual maturity between the ages of four and eight and may be reproductive until age 20. Their gestation period ranges from 95 to 160 days. In about half of their pregnancies, twins are birthed. In the wild, usually only one twin survives, due to the mother selecting the stronger cub to care for and neglecting the weaker.

Only about 1,600 Giant Pandas remain in the wild. About 300 live in zoos and breeding centers around the world, mostly in China. Giant Pandas are listed as “Endangered” by the International Union for Conservation of Nature. Their population is threatened by continued habitat loss, habitat fragmentation, and by a very low birthrate-- both in the wild and in captivity.