Ornithological artist Keith Hansen is hand-painting roughly 1,000 bird species recorded in the US and Canada for Flock, an app designed to encourage people to leave their screens and go birdwatching. The project matters because it combines detailed natural-history artwork with technology intended to build interest in birds and conservation rather than maximise users’ time online.

Hansen had completed 420 illustrations, including a painted bunting, leaving 584 to finish; the collection excludes Hawaiian birds but includes species found up to 200 miles offshore. Flock was created by his friends Adam Donkin, a former Amazon product designer, and Bob Stevenson, a veteran video-game designer, drawing on their shared long-standing enthusiasm for birding.