Diet and chemical defenses of the Sonoran Desert toad
PLoS ONE – November 10, 2025
Source: OpenAlex
Summary
The Sonoran Desert toad uniquely secretes the psychedelic compound 5-MeO-DMT as a chemical defense. Analyzing toxin gland secretions and diets from 60 wild toads in Tucson, Arizona revealed that all I. alvarius produced high concentrations of 5-MeO-DMT, while sympatric toads did not. Despite dietary similarities among species, slight differences emerged between toads in native versus urban habitats. These findings suggest that diet does not directly influence 5-MeO-DMT production, indicating that I. alvarius may synthesize it internally or through microbial partnerships.
Abstract
The Sonoran Desert toad (Incilius alvarius) is the only animal known to secrete the psychedelic compound 5-MeO-DMT as a chemical defense, but the source of 5-MeO-DMT in I. alvarius remains unknown. Some amphibians produce chemical defenses endogenously or through symbiotic interactions, while others acquire them from specialized diets. In this study we analyzed toxin gland secretions and diet profiles from wild I. alvarius and sympatric anurans from native and urban habitats around Tucson, Arizona to explore possible links between diet and 5-MeO-DMT production. All I. alvarius secreted high concentrations of 5-MeO-DMT, whereas other sympatric toads did not. The diet of I. alvarius was similar to that of sympatric anurans, indicating that I. alvarius does not exhibit relative dietary specialization. We found slight dietary differences between I. alvarius in native and urbanized habitats. Taken together, these lines of evidence suggest that diet is not directly linked to 5-MeO-DMT production and support the alternative hypotheses that I. alvarius synthesizes 5-MeO-DMT endogenously or via a microbial symbiont.