Human-caused deaths of 10-30 white-tailed eagles (Haliaeetus albicilla, hereafter WT eagles) were reported every year in Japan. Among these, 7 or more individuals on average were killed or suspected to be killed by avian collisions with wind turbines. Importance of cumulative impact assessment is asked in Japanese environmental impact assessment (EIA) procedures. We have no guideline of methods to reduce the cumulative impact in Japanese EIAs. If the population persistence of endangered raptors is an endpoint of EIAs, potential biological removal (PBR) ) is probably a good indicator to decide the limit of cumulative avian collisions. In many birds, eg, white-fronted geese or other migratory geese, the actual collisions are definitely lower than PBR. PBR.The PBR of WT eagles depends on scenarios; (1) including migratory eagles in wintering or not and (2) intrinsic growth rate. We propose how to evaluate PBR of WT eagles and discuss about how to utilize this indicator to future EIAs of wind farms in Japan.