eBird: record bird sightings and support nature science

eBird is the Cornell Lab of Ornithology's global platform where birdwatchers keep checklists of the birds they see and hear, noting when, where and how they went birding. The data are freely accessible and are used in science, conservation and education. A free mobile app lets you record sightings offline anywhere in the world. The site has separate resources for young birders, and there is no participation deadline.