A winter survey of bird populations conducted during the Christmas period - December 14 to January 5th inclusive.  More than 1800 counts are conducted each year across Canada, the United States and Latin America.  On a selected day within the count period, local birders count as many birds as possible within a 24 km (15 mile) diameter circle.  The Christmas Bird Count had long been organized on the continental scale by the New York-based National Audubon Society. In 2000, Audubon finalized an agreement with Bird Studies Canada that would see BSC partner with Audubon to coordinate CBCs in Canada.  This layer represents the 24 km circles surveyed as part of each Christmas Bird Count conducted in Canada.  An accompanying layer (CBC_PT) contains the centre point of the circles.