Potential avian impacts are often a keyliability component of Natural ResourceDamage Assessment (NRD) under the OilPollution Act of 1990 (OPA). This paper hasthree purposes. The first is to provide NRDpractitioners with an overview of methodscommonly used to asses acute avian mortalityfollowing oil spills. The second purpose is toprovide NRD practitioners with anunderstanding of the BBM, the data requiredto support BBM modeling, uncertaintiesassociated with BBM results, and steps thatcan be taken to reduce those uncertainties.Finally, we outline methods designed to helpTrustee and responsible party representativescooperatively identify optimal strategiesthroughout the BBM process.