A comparison of two methods of estimating bird mortalities from field‐applied pesticides

Abstract

Abstract-At least two search methods for bird carcasses have been suggested to estimate bird mortality from the use of a pesticide, one outlined by the U.S. Environmental Protection Agency (EPA) and one we propose. The proposed estimator provides a nonparametric, model-free procedure for estimation of nontarget bird kills. Data were collected during a field study to compare the methods. These data were used to provide parameters for a computer simulation comparing characteristics of the mortality estimates produced by the two methods. The proposed method demonstrates marked advantages with respect to bias and mean squared error when compared to several interpretations of the EPA method in various search and mortality scenarios. In addition, the proposed method often provides estimates in instances where the EPA method cannot. The proposed estimator allows the estimation of search efficiency and survival probability simultaneously.