"eBird is the world’s largest biodiversity-related citizen science project, with more than 100 million bird sightings contributed each year by eBirders around the world. A collaborative enterprise with hundreds of partner organizations, thousands of regional experts, and hundreds of thousands of users, eBird is managed by the Cornell Lab of Ornithology. eBird data document bird distribution, abundance, habitat use, and trends through checklist data collected within a simple, scientific framework. Birders enter when, where, and how they went birding, and then fill out a checklist of all the birds seen and heard during the outing. eBird’s free mobile app allows offline data collection anywhere in the world, and the website provides many ways to explore and summarize your data and other observations from the global eBird community. eBird is available worldwide, comprising a network of local, national, and international partners. eBird directly collaborates with hundreds of partner groups for regional data entry portals, outreach, engagement, and local impact. Data quality is of critical importance. When entering sightings, observers are presented with a list of likely birds for that date and region. These checklist filters are developed by some of the most knowledgeable bird distribution experts in the world. When unusual birds are seen, or high counts are reported, the regional experts review these records. eBird data are stored across secure facilities, archived daily, and are freely accessible to anyone. eBird data have been used in hundreds of conservation decisions and peer-reviewed papers, thousands of student projects, and help inform bird research worldwide. "
" Find more birds Keep track of your bird lists, photos, and sounds Explore latest sightings from around the world Join the world’s largest birding community Contribute to science and conservation eBird began with a simple idea—that every birdwatcher has unique knowledge and experience. Our goal is to gather this information in the form of checklists of birds, archive it, and freely share it to power new data-driven approaches to science, conservation and education. At the same time, we develop tools that make birding more rewarding. From being able to manage lists, photos and audio recordings, to seeing real-time maps of species distribution, to alerts that let you know when species have been seen, we strive to provide the most current and useful information to the birding community."
How to participate
There are comprehensive instructions here: https://support.ebird.org/support/home, https://support.ebird.org/support/solutions/articles/48000957911 and a free online training: https://academy.allaboutbirds.org/product/ebird-essentials/