The nation's longest-running community science bird project fuels Audubon's work throughout the year. The data collected by observers provides a picture of how bird populations change in time and space over time.  Each year we look for community members to join us and help us count birds ! 

How are data from the Christmas Bird Count used?

CBC data have been used in hundreds of analyses, peer-reviewed publications, and government reports over the decades. Consult our bibliography page or use Google Scholar to search for research using CBC data. Yearly summaries of CBC data submitted by each circle compiler can be found through this page.

Audubon’s quantitative ecologist updates the CBC Population Trends periodically which can be viewed and downloaded from this page. 

A few recent publications using CBC data include the following:
A 2021 study published in the Journal of Wildlife Management was conducted by the National Audubon Society and Clemson University’s James C. Kennedy Waterfowl and Wetlands Conservation Center. This publication showed populations of 16 common duck species that winter in the Southeastern U.S. have shifted northward over the past 50 years due to temperature changes attributed to climate warming. A 2019 publication lead by Audubon presented a new CBC data modeling approach that increases the spatial resolution of trend estimates that can provide reasonable large-scale trend estimates for users interested in general patterns, while also providing higher-resolution estimates for examining correlates of abundance trends at finer spatial scales, which is a prerequisite for tailoring management plans to local conditions.

For other frequently asked questions visit this page.