38573d6e_International_Joint_Commission__Delisting_Guideline
[BUI] BIRD OR ANIMAL DEFORMITIES OR REPRODUCTIVE PROBLEM [Listing Guideline] When wildlife survey data confirm the presence of deformities (e.g. cross-bill syndrome) or other reproductive problems (e.g. egg-shell thinning) in sentinel wildlife species. [Delisting Guideline] 
When the incidence rates of deformities (e.g. cross-bill syndrome) or reproductive problems (e.g. egg-shell thinning) in sentinel wildlife species do not exceed background levels in inland control population
International Joint Commission
Delisting Guideline