One of the fun aspects of birding is there is always something new to learn and always a new ID challenge. Use these resources to improve your skills and test you knowledge.
Test Your Skills
Test your identification skills using this ID quiz by Tony Leukering, Bill Maynard and others who hosted a weekly bird identification contest on the CFO website between 2012 and 2017.
CFO Facebook Group
The Colorado birding community shares observations and other information related to birds and birding in Colorado. You can ask questions about birds you see in Colorado.
COBirds is a CFO-supported Google Group for the discussion of Colorado birds. Ask questions about the birds you see in Colorado and learn from what others post.