How the Christmas Bird Count Helps Birds

Christmas Bird Count circles in the western hemisphere
Christmas Bird Count circles in the western hemisphere

How Christmas Bird Count Helps Protect Species and Their Habitat

The data collected by observers over the past century allow researchers, conservation biologists, and other interested individuals to study the long-term health and status of bird populations across North America. When combined with other surveys such as the Breeding Bird Survey, it provides a picture of how the continent's bird populations have changed in time and space over the past hundred years.

The long term perspective made possible by the Christmas Bird Count is vital for conservationists. It informs strategies to protect birds and their habitat - and helps identify environmental issues with implications for people as well. For example, local trends in bird populations can indicate habitat fragmentation or signal an immediate environmental threat, such as groundwater contamination or poisoning from improper use of pesticides.

In the 1980's CBC data documented the decline of wintering populations of the American Black Duck, after which conservation measures were put into effect to reduce hunting pressure on this species. More recently, in 2009, the data were instrumental in Audubon's Birds & Climate Change analysis, which documented range shifts of bird species over time. Also in 2009 CBC data were instrumental in the collaborative report  by the North American Bird Conservation Initiative,  U.S. Fish & Wildlife Service - State of the Birds 2009 . The Environmental Protection Agency (EPA) has included Audubon's climate change work from CBC data as one of 26 indicators of climate change in their 2012 report.

In 2007, the data were instrumental in the development of two Audubon State of the Birds Reports - Common Birds in Decline, which revealed that some of America's most beloved and familiar birds have taken a nosedive over the past forty years, and WatchList 2007, which identified 178 rarer species in the continental U.S. and 39 in Hawaii that are imperiled. These three reports helped scientists and policy-makers to both identify threats to birds and habitat, and promote broad awareness of the need to address them.

Below are some things we are learning about through Christmas Bird Count Data.

The Hooded Merganser: A Preliminary Look at Growth in Numbers in the United States as Demonstrated in the Christmas Bird Count Database by Steve Davis and Peter Capobianco, American Birds, Summary of the 106th CBC

Using Christmas Bird Count Data to Assess Population Dynamics and Trends of Waterbirds by Gregory S. Butcher, Daniel K. Niven, John R. Sauer, American Birds, Summary of the 105th CBC

Sympatry of Grassquits on New providence Island, Bahamas, Based on Analysis of CBC Data by Anthony White, John Bjerke, Paul Dean, Kathleen Sealey, American Birds, Summary of the 105th CBC

Christmas Bird Count Provides Insights Into Population Change in Land Birds That Breed in the Boreal Forest by Daniel K. Niven, John R. Sauer, Gregory S. Butcher, and William A. Link, American Birds, Summary of the 104th CBC

Statistical Analyses Make the Christmas Bird Count Relevant for Conservation by John R. Sauer, Daniel K. Niven, and William A. Link, American Birds, Summary of the 104th CBC

Christmas Bird Count Data Suggest West Nile Virus May Not Be A Conservation Issue in Northeastern United States by Carolee Caffrey and Charles C. Peterson, American Birds, Summary of the 103rd CBC

Combined Data of Project FeederWatch and the Christmas Bird Count Indicate Declines of Chickadees and Corvids: Possible Impacts of West Nile Virus by David N. Bonter and Wesley M. Hochachka, American Birds, Summary of the 103rd CBC

Ten Things We Learned from Audubon's Christmas Bird Count

Demise of the Eastern Bewick's Wren

Population Trends in Evening Grosbeak

Dove Expansions in North America

Pine Siskins across North America

Tufted Titmouse Range Expansion

Grackle Expansion

American Kestrel

Nuttall's Woodpeckers