High Quality Content by WIKIPEDIA articles! A bird atlas is an ornithological work that attempts to provide information on the distribution, abundance, long-term change as well as seasonal patterns of bird occurrence and usually represented in the form of maps. They often involve the use of large numbers of volunteers who help cover a large geographic region and the methods used are standardized so that the studies can be continued in the future and ensure comparison of results over time. In many cases the species covered are restricted to those that breed or are resident. Migration atlases on the other hand cover migratory birds and usually consist of maps showing summaries of ringing and recoveries.