The Christmas Bird Count (CBC) is a census of
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s in the Western Hemisphere, performed annually in the early Northern-hemisphere winter by volunteer
birdwatchers
Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, by ...
and administered by the
National Audubon Society. The purpose is to provide population data for use in science, especially
conservation biology, though many people participate for recreation. The CBC is the longest-running
citizen science survey in the world.
History
![Portrait of Frank Chapman](https://upload.wikimedia.org/wikipedia/commons/1/16/Portrait_of_Frank_Chapman.jpg)
Up through the 19th century, many
North Americans participated in the tradition of
Christmas
Christmas is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world. A feast central to the Christian liturgical year ...
"side hunts", in which they competed at how many birds they could kill,
regardless of whether they had any use for the carcasses and of whether the birds were beneficial, beautiful, or rare. In December 1900, the U.S. ornithologist
Frank Chapman, founder of Bird-Lore (which became
Audubon magazine
''Audubon'' is the flagship journal of the National Audubon Society. It is profusely illustrated and focuses on subjects related to nature, with a special emphasis on birds. New issues are published bi-monthly for society members. An active blo ...
), proposed counting birds on Christmas instead of killing them.
On Christmas Day of that year, 27 observers took part in the first count in 25 places in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
and
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, the count totaling 18,500 individual birds belonging to 90 species.
Since then the counts have been held every winter, usually with increasing numbers of observers. For instance, the 101st count, in the winter of 2000–2001, involved 52,471 people in 1,823 places in 17 countries (but mostly in the U.S. and Canada). During the 113th count (winter 2012–2013), 71,531 people participated in 2,369 locations. The National Audubon Society now partners with
Bird Studies Canada
Birds Canada (formerly Bird Studies Canada) is Canada's national bird conservation organization. Birds Canada began as the ''Long Point Bird Observatory'' in 1960, changing its name in 1998 to reflect the growing national scope of its research p ...
, the
Gulf Coast Bird Observatory of
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
(responsible for CBCs in
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
), and the
Red Nacional de Observadores de Aves (RNOA, National Network of Bird Observers) and the
Instituto Alexander von Humboldt of
Colombia.
The greatest number of bird species ever reported by any U.S. location in a single count is 250, observed on December 19, 2005 in the Matagorda County-Mad Island Marsh count circle around
Matagorda and
Palacios, Texas
Palacios ( ) is a city in Matagorda County, Texas, United States. The population was 4,395 at the 2020 census.
Etymology
Popular local legend states that the area was named Tres Palacios ("Three Palaces") several centuries ago by shipwrecked Span ...
. The greatest number of bird species ever reported by a CBC circle in the world is 531, observed on December 21, 2013 in the Cosanga-Narupa count (previously known as the Yanayacu count) on the eastern slope of the Andes in Ecuador.
Methods
Participation in the Count is open to all, and as of 2012 participation was free of charge.
Each individual count is performed in a "count circle" with a diameter of 15 miles (24.14 kilometres).
At least ten volunteers, including a compiler to manage things, count in each circle. They break up into small parties and follow assigned routes, which change little from year to year, counting every bird they see. In most count circles, some people also watch feeders instead of following routes.
Counts can be held on any day from December 14 to January 5 inclusive.
The results are by no means as accurate as a human census. The experience of the observing birders influences both species identification and quality of locations examined.
Not all the area in the count circles is covered, and not every bird along the routes is seen or identified. Big flocks can't be counted precisely. Also, telling whether a bird has been counted twice can be difficult. The rules address this problem by prohibiting counting birds when retracing one's route, except for species that the party hasn't seen before. Also, when a large roost of some species occurs in a count circle, an expert estimates the number for that species during the morning or evening and usually no individuals are counted at other times. Observers can attempt to keep track of flocks of mobile birds such as crows, and can use their judgement, even sometimes recognizing an individual bird or at least that two birds of the same species are different individuals.
The results, providing data on winter ranges of birds, are complementary to those of the
Breeding Bird Surveys.
See also
*
Australian Bird Count The Australian Bird Count (ABC) was a project of the Royal Australasian Ornithologists Union (RAOU). Following the first and successful Atlas of Australian Birds project, which led to the publication of a book on the distribution of Australian bir ...
(ABC)
*
BioBlitz
A BioBlitz, also written without capitals as bioblitz, is an intense period of biological surveying in an attempt to record all the living species within a designated area. Groups of scientists, naturalists and volunteers conduct an intensive f ...
("24-hour inventory")
*
Breeding Bird Survey
*
Great Backyard Bird Count The Great Backyard Bird Count (GBBC) is a community science project in ornithology. It is conducted annually in mid-February. The event is supported by the Cornell Lab of Ornithology and the National Audubon Society
The National Audubon Society ( ...
*
Tucson Bird Count (TBC) (in Arizona in the US)
*
Citizen science
References
Further reading
* {{Cite news, url=https://www.newspapers.com/clip/23148413/bird_count_more_than_just_game/, title=Bird count more than just a game, last=Richman, first=Talia, date=January 1, 2018, work=The Baltimore Sun, access-date=August 26, 2018, pages=1, 9, via=Newspapers.com Page 9 content located at https://www.newspapers.com/clip/23180435/christmas_bird_count_more_than_game_pt2/ .
External links
Audubon Official CBC page(in Spanish)
Bird censuses
Ornithological citizen science