Species on the Review List must be acceptably documented before adding them to the official record. This List consists of all the birds that have either never or very rarely occurred in Ohio.
The OBRC considers changes to the Review List at its annual meetings. The List is compiled (beyond including all species never accepted for Ohio) by including all species averaging fewer than two records per year over the latest ten-year period, adding selected species that have averaged between two and three records per year in a similar span, then adding a few species whose populations are declining precipitously even if they exceed other numerical criteria (no species are in the list for this reason now, though in recent years examples have included Piping Plover and Loggerhead Shrike).There are currently over 9,000 of the former and 100+ of the latter, a list of which follows:
Trumpeter Swan (other than introduced birds)
Northern Hawk Owl
Great Gray Owl
Black-throated Gray Warbler