The Desert Cottontail thrives in the Sonoran Desert, testament to its adaptability. Creosote Bush is the most abundant plant across much of the southwestern USA deserts, however, the abundance of noxious chemicals in the leaves makes it unpalatable or even deadly toxic to most herbivores. The Desert Cottontail deals with creosote's toxic brew by consuming only limited quantities at one time and then only the least defended twig sections it can find.

Evidence of this selective herbivory can be found during drought periods as sprigs of dry, brown creosote leaves deposited around the periphery of shrubs after the less toxic twig portions have been eaten. What is the method the cottontail uses to discriminate toxic from safe portions? (Possible science project or thesis!)