Each winter throughout the latter part of the 19th century, sportsmen would gather to compete in an annual bird hunt called “side hunts”. Everything they saw was shot, regardless of whether it was edible or rare. This was a popular pastime and undoubtedly contributed to significant avian declines during the period.
In the 1890s Frank Chapman, author of Handbook of the Birds of North America and founder of Bird Lore magazine (later to become Audubon magazine), attempted to halt this consumptive and damaging practice. He proposed that people only count birds, rather than shoot them. One has to understand, at the time, conservation was not on anybody’s mind and even ornithologists shot thousands of birds annually to collect their skins for museum specimens; so Chapman’s concept was unique in many ways.
The beginnings were simple enough. In 1900, under the encouragement of Chapman, 27 observers took part in the first Christmas Bird Censuses, as they were called at the time, in Canada and the USA. From these humble beginnings, almost 100,000 people now count birds, in thousands of places all over the Western Hemisphere, mostly in North America.
The concept is simple, an area of interest and significance is identified by a local birding group and a count circle is established. A count circle, an area 24 kilometers in diameter, is surveyed annually by interested birders, during a two week period around the Christmas season. Every bird seen or heard is counted and the records are compiled annually and submitted to the National Audubon Society or Birds Canada.
The dates of the individual counts are fixed, so consistency is achieved and data comparisons can be made. There’s no logic in doing a Christmas Bird Count (CBC) in June, after all, and expecting to compare the results to one done in December.
In recent years, people can choose to ‘feeder watch’ rather than go out into the field, which allows more people to participate and assists persons with mobility issues. It is also a great addition to the data collected as more birds are counted, which otherwise might have been missed as they hide in someone’s back yard.
So how good is the data? Well, generally very good, but there are a few problems: variable observer skill, ability to estimate when large numbers of birds are seen in a flock, duplicate counting, and missed areas of coverage must all be considered when analyzing the results. That said, millions of bits of data are collected annually, and as the longevity of the individual count grows, patterns can be seen and understood. So despite the difficulties inherent in citizen science censuses, such as this, the data is hugely valuable to researchers and scientists.
So who uses this data and how? Many scientists, municipalities, governments and consultants rely on this data to study long-term trends and the status of individual species and populations of birds in given areas. The beauty of the CBC is, they deal with birds that are wintering and as such rely exclusively on the local habitats. This persistence and fidelity to a locale means a great deal, when trying to analyze the long term health of an ecosystem.
So how many birds are counted, by whom and where? In the first count in 1900, 18,500 birds were counted by 27 people. In 2018-19, 461 counts were run in Canada, involving 11,209 field counters and 3,745 feeder watchers, finding almost 3 million birds of 285 species! And that’s only Canada!
Locally, CBC counts are run in many municipalities across North America. Interested in finding out more about these censuses, who runs them, and joining a count this December? Visit www.birdscanada.org/apps/cbc/mapviewer.jsp.
Locally, counts are held in Uxbridge, Sturgeon Lake (Lindsay), Kawartha (Bobcaygeon), Beaverton, Orono, Pickering and Oshawa. Some nature clubs (e.g. North Durham Nature) also have counts designed for kids, to encourage their early interest in nature. What a great way to celebrate our birds and the holiday season!
Geoff Carpentier is a published author, expedition guide and environmental consultant. Visit Geoff on-line at www.avocetnatureservices.com and on LinkedIn and Facebook.