Applying hierarchical resource selection concepts to solving crop damage caused by birds

Recovery of Greater Sandhill Cranes (Grus canadensis tabida) is a conservation success but will increase the potential for crop damage if problems caused by high crane density remain unresolved. In spring, cranes consume planted corn kernels (Zea mays), causing significant damage. From 1999 to 2001 and 2007 to 2009 we experimented with resolving crane damage. Seeds treated with either insecticides or anthraquinone (AQ) were not consumed in planted fields while untreated seeds were, causing a 19.6% reduction in seedling density where cranes foraged. Insecticides tested were inappropriate for future use while performance of AQ mimicked that of insecticides but was environmentally acceptable and economical to use. Though cranes selected germinating corn fields, regardless of treatment, they used fields containing treated corn without causing damage. Cranes were generalists when selecting food items within a field and likely switched food items when exposed to treated corn but were specialists when selecting field types within a home range. Deterrence at geographic scales where species are generalists may reduce the chance for habituation. Subsequent deployment of AQ has been replicated with other bird species and crops at landscape scales. Successful solutions enable landowners to value wildlife and promote biological diversity found on those lands.