Date of this Version
PROCEEDINGS OF THE NORTH AMERICAN CRANE WORKSHOP 14:89-100
Several species of cranes and other wildlife have recovered from low populations because, in part, they have adapted to resources found in agricultural environments. If future conservation strategies are to succeed in areas dominated by agricultural use, we must develop sustainable models that solve crop damage problems that are caused by expanding wildlife populations. Using crane damage to planted seed as an example, we propose 1 such model of sustainable crop damage prevention. The deterrent, 9,10-anthraquinone (AQ), is a natural product produced by plants, in part to control bird frugivory, and induces gastro-intestinal distress (temporarily sickens an individual) in sandhill cranes (Grus canadensis) as well as other bird species. AQ is an effective deterrent because it induces a physiological response at first and is then accompanied by a conditioned avoidance. Yet, AQ is not toxic to birds nor are birds likely to habituate to the deterrent. Seed repellents cause birds to avoid treated foods among several possible items found within the same field. Other, more traditional, crop damage repellents (e.g., propane cannons) operate by moving birds among fields within home ranges. Excluding preferred habitats such as cornfields increases the risk that birds will habituate to deployed damage solutions. AQ products have adapted to a diverse farm environment and cost less than 3% of total planting costs. They were applied to prevent crane damage on planted corn for more than 67,000 ha in the Midwest during 2018 and can be deployed at whatever spatial scale that damage severity warrants. Our model using AQ as a seed treatment to prevent crane damage to germinating corn has been applied to pheasants (Phasianus colchicus) and blackbirds (Icteridae) as well as in rice and sunflower crops. As such, this model presents a sustainable approach that arises from solutions that allow agriculture and wildlife to co-exist.