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Intentional provisioning of food and water at specific locations, commonly bird feeders and bird baths, may alter bird and mammal abundance, distribution, and recruitment; yet no studies have examined the indirect effects of resource supplementation on terrestrial reptilian mesopredators such as rattlesnakes. In the southwestern deserts of North America, anecdotal evidence suggests provisioning birds with food and water attracts rattlesnakes to exurban yards, either indirectly by increasing prey availability or directly through attraction to water. We conducted the first experimental test of this hypothesis by providing bird seed, water, or bird seed and water at 2 national monuments in Arizona, USA, and followed the responses of adult western diamond-backed rattlesnakes (Crotalus atrox) equipped with radio-transmitters, and endothermic prey species, primarily rodents, birds, and lagomorphs. We found differing responses among prey taxa to supplemental food and water provisioning: rodents showed no response to any treatment, birds responded to food treatments, and lagomorphs responded to water treatments. Overall, spatial responses by adult rattlesnakes were weak, but several subjects appeared to respond to individual treatment grids. We did not find evidence of a direct response by rattlesnakes to supplemental water. Overall, we found little support for the prevalent belief that food and water sources at provisioning stations increase local concentrations of rattlesnakes; we provide several explanations for this counter-intuitive result. (c) 2015 The Wildlife Society.