Predicting the Response of Bird Populations to Wind Energy-Related Deaths

The expansion of wind energy developments has been accompanied by concerns over unforeseen bird deaths caused by striking turbine blades and turbine support structures. We conducted sensitivity analyses using Leslie matrix models to determine the effects of survivial of age classes on population growth rates (termed lambda). Population growth rate for ducks is roughly equally sensitive to changesin the juvenile and adult survival rates. For geese, the nonadult age classes survival rates seem to have little impact on population growth. For the adult age class, population growth is extrememly sensitive to changes in the adult survival rate. For gulls, except for very small survival rates, the changes in the adult age class gives the largest change in population growth. The situation forthe eagle is very similar to the situation for the gull but even more extreme. Our results show that careful evaluation of how life-history parameters could interact to influence population persistence can be used as a first approximation of the influence of wind energy developments on bird populations.