There have been several significant transition points in 蜜柚APP’s Christmas Bird Count program since Frank Chapman launched it during the 1900 holiday season. Since that inaugural count, people have always counted every bird of all species encountered during one calendar day; they have reported the number of observers and time and distance during that day, from a prescribed area, making sure to minimize the possibility of double counting. With Frank Chapman’s retirement in 1934 came the first big inflection point. To ensure the longevity of the program, Chapman handed the reins of the CBC over to an advisory board and team of editors, which included the now-legendary Chandler S. Robbins. The next big change arrived in the 1950s, when the CBC team standardized the area of each count to be a 15-mile, or 24-kilometre, circle; this meant that some of the older counts needed to be combined into these new, larger circles. The count expanded again during the 73rd CBC, in December...