Marty Floyd, of the Natural Resources Conservation Service, prepared this summary of the changes in CBC methodology through the 88th CBC (1987-88).
| CBC # | Changes |
|---|---|
| 1st | 25 counts with 27 participants, published in Bird Lore (Jan.-Feb.) |
| 17th | Fifteen mile circle diameter established |
| 38th | Added miles along with hours of count |
| 41st | $0.10/person fee established |
| 42nd | Counts published in Audubon Magazine supplement |
| 45th | Added habitat percentages |
| 48th | Fee discontinued, published in Audubon Field Notes |
| 51st | Designated party-miles and party-hours on foot, by car, etc. |
| 54th | Listed species seen day before/after count day but not on count day |
| 56th | Listed species seen during count period but not on count day |
| 57th | Fee re-established at $0.50/person, established minimum of 8 hours except in Arctic |
| 67th | Established latitude/longitude of count center |
| 69th | $1.00/person fee |
| 72nd | Published in American Birds |
| 74th | Number of feeder watchers included; extra $1.00 for non-subscribers to receive copy of American Birds CBC issue |
| 75th | Feeder watcher number and hours included; Rock Dove counted |
| 76th | Request for list of mammals seen on counts |
| 77th | $1.50/person fee |
| 80th | Owling hours included |
| 83rd | Owling miles and hours counted separately |
| 85th | $3/person fee |
| 86th | Referred to description in earlier publication |
| 87th | Format change to tabular form |
| 88th | Return to original format; raise fee to $5 |