Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
The collection and analysis of data relating to the natural world by members of the general public, typically as part of a collaborative project with professional scientists.
Share your knowledge with the community
Browse our collection of 300,000+ community-written definitions