= only includes birds identified by sight.
The ABA Area now includes Hawaii (ABA Checklist update, and official listing area definition coming later this year). Please do not enter year or month list totals in the ABA Area before 2017.
ABA Continental is the ABA area by pre-2017 definition, that is, without Hawaii.
AT stands for All Territories & Provinces Added Together, and is determined by adding one’s life lists for each of Canada’s provinces and territories, 13 areas in all, whether or not you have reached the reporting threshold in all (or any) of them.
TT (Total Ticks) is the same principle, but on a wider scale. It includes all the states, provinces, and territories that lie within the ABA Area (thereby excluding Hawaii, but including Washington DC and the French islands of St. Pierre et Miquelon, which are in the ABA Area).