The contest is divided into five categories: birds, mammals, insects, urban wildlife and junior photographers (15 and under).
This year, Tam Wing-yan of Edmonton, Canada, won the junior category for the second consecutive year. She successfully photographed a hummingbird mid-flight, an enviable achievement for any photographer, let alone a 15-year-old.
'Hummingbirds fly really quickly and their wings move really fast. To capture the fast-moving wings, the shutter speed [of the camera] has to be really high,' Wing says. 'Hummingbirds are the only birds that can fly backwards, which makes them more difficult to capture.'
In fact, depending on the species, hummingbirds flap their wings 12 to 90 times a second, giving them that distinctive hovering mode.
As part of a collaboration between Canada Post, Canadian Geographic Wildlife and the Canadian Museum of Nature, winners of the contest had their shots featured on one million stamps across the country.
Wing first found out about the contest through her father, an avid photographer who taught her about the art.
She credits her father as her muse, but appreciates both parents' support and encouragement, especially when she's feeling discouraged after a bad shooting session.
'My parents encourage me all the time,' she says. 'I learned all my skills from my dad and books about photography.'
A natural affinity for wildlife made entering the contest an easy choice. Wing could not pass up the opportunity, saying it presented her with a chance to carve a niche for herself and her work.
'I like to shoot wildlife because it is so amazing - like how different [animals] are from humans. In order to learn more about them, I try to take photos,' Wing says. 'I most like to photograph butterflies.'
Wing treats photography as a hobby, but also understands the artistic side of it. '[It's] a way for me to express my feelings,' she says.
Wing moved to Canada from Hong Kong in 2006 because her parents wanted Wing to receive a Canadian education. But it was not always easy for her to adapt to a foreign environment, and it took some time to become acclimated to a different way of life. She took consolation in knowing that her friends were only a phone call away.
'The saddest part about leaving was the separation from my friends. I had only been to Canada once before,' Wing says. 'I still don't feel like I belong to this country yet, but I started to feel accepted after I made some friends here.'
On her status as an up and coming photographer, Wing says she is not much of a celebrity at school. Only a handful of her classmates know about her achievements, and she prefers it that way.
'A girl like myself, how popular can I be?'
Wing's stamps, along with the other winners of the contest, can be bought from the Canada Post website.