Aptly christened Birdsnap, the free app enables users to identify bird species through uploaded photos, accompanies a visually beautiful, comprehensive website that includes some 50,000 images.

Birdsnap, which also features birdcalls for each species, offers users numerous ways to organise species-alphabetically, by their relationship in the Tree of Life, and by the frequency with which they are sighted at a particular place and season.

The researchers developed Birdsnap using computer vision and machine learning techniques."Our goal is to use computer vision and artificial intelligence to create a digital field guide that will help people learn to recognise birds," said Peter Belhumeur, a computer science professor at Columbia University.

"We have been able to take an incredible collection of data-thousands of photos of birds-and use technology to organise the data in a useful and fun way," Belhumeur added.

The app features 500 of the most common North American bird species.