Simulation modelling of red-winged blackbird impact on grain crops.
Abstract
Preliminary estimates suggested that maize contributed 30% of the toal food biomass consumed by the birds during the post-breeding roosting phase, and 65% of this maize was taken in the area 12-36 km from the roost epicentre. Maize consumption was estimated to represent 0.2-16.2% of the agricultural yield, with impact greatest near the roost epicentre. Model analysis suggested that altering agricultural cropping patterns in areas close to roosts or increasing the availability of insects or wheat-oat 'detritus' should be considered as possible alternative to more direct control measures in the management of this bird-crop system.