A survey was conducted to determine if carcinogenic mycotoxins were present in foods consumed by Mississippi sandhill cranes (Grus canadensis pulla). Samples of field corn (Zea mays) (n = 111) and chufa (Cyperus esculentus) (n = 20), obtained in 1987, 1988 and 1989 on the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) and nearby private lands were analyzed for aflatoxin B₁(AB₁), ochratoxin A and sterigmatocystin using thin layer chromatography. Chufa samples were negative for all three mycotoxins. Aflatoxin B₁ was found in corn at concentrations from 5 to 5,000 ppb; the other mycotoxins were not found in corn. Contaminated corn was found in 72% of all corn fields, but the proportion of contaminated fields was 57 to 100% for the 3-yr period. Contamination with AB₁ was greatest in corn obtained from the ground post-harvest. Overall, 32% of corn samples from the ground had levels ≥200 ppb with a mean of 427 ppb (range = 5 to 5,000 ppb) in contaminated fields. In 1989, mean AB₁ concentration in corn on the ground was 5 to 1138 ppb for individual fields. The concentration of AB₁ was ≤200 ppb in all corn samples from upright stalks. The study demonstrated that AB₁ is available to sandhill cranes and at levels that may pose a serious health threat.