It's hard to believe that the Toronto Zoo's panda cubs squirmed their way into the city's hearts just one year ago.

The Toronto Zoo's two panda cubs hanging out in their enclosure on their first birthday. (Martin Trainor/CBC)

The zoo celebrated Jia Panpan and Jia Yueyue's first birthday with a heart-melting video this morning; have a tissue ready.

Happy birthday, little guys!

Some birthday cake and cupcakes for the panda cubs' first birthday party. (Martin Trainor/CBC)

Toronto Zoo staff laid out quite a tasty spread for the birthday boy and girl.

Happy birthday, Jia Panpan and Jia Yueyue. The panda cubs turned one years old today. (Martin Trainor/CBC News)

In more serious news, the zoo's also celebrating the fact that, since the cubs were born, a leading international conservation group has advised that giant pandas are no longer considered endangered.

Toronto Zoo staff celebrate the pandas' first birthday. (Martin Trainor/CBC)

Instead, the International Union for the Conservation of Nature says the animals should be downgraded to a "vulnerable" species as their worldwide population has grown to 1,864 — up nearly 270 pandas — since 2004, The Associated Press reported.