Birding, or birdwatching, can be done just about anywhere, and combined with many other hobbies. It brings an enjoyment and appreciation of nature, and it's something you can share with family and friends. You can go hiking and look for birds at the same time; you can bird while you travel; you can see birds just going between work and the parking lot. The hobby can be done at any level, for minimal expenditure or expensive outlays or anywhere in between.
All About Birds from the Cornell Lab of Ornithology
Aiken Audubon Society: Colorado Springs area chapter of the Audubon Society
Colorado Checklists by County - click on El Paso
Colorado Rare Bird Alerts: Google Group
ebird.org including state of Colorado sightings (Beta as of 1/22/2015)
Macaulay Library: recordings of bird songs
Here are some selected works. For a more comprehensive search, try birds colorado as a subject search in the library catalog.
Author: Scott Catron. Creative Commons Attribution-ShareAlike 3.0 Unported