A unique competition to photograph some of the world's rarest birds has produced incredible pictures.
The effort, sponsored by BirdLife International's Preventing Extinctions Program, asked amateur photographers to submit images of some of the most threatened species around the globe, both endangered and critically endangered. Many of these birds face extinction due to habitat destruction and the introduction of invasive species.
After two annual competitions, more than 800 of the photos showcasing 515 species have been compiled in a newly released book, The World's Rarest Birds.
Take a look at the winners of the 2012 challenge below.