The hunt was not for food - it was a contest to shoot and kill the most birds and other small animals. So Chapman decided that he and some friends could start another tradition - to count the birds instead of hunt them. The count is done in early winter within a two week time period. Birdwatchers document the species they spot or even hear and note them on a form. These forms are then tabulated and a regional and national census are published every year.
Great effort is taken to formulate accurate reports.
Some birds are migratory, some birds could be misidentified - all of these factors are taken into account. As a result, we all benefit from this survey, we can not only have a more accurate picture of the bird population, we can keep tabs on the health of many individual species and a general take on the condition of our environment.