BIRD BRAINS SPOT TUMORS After being rewarded with food when correctly spotting breast tumors, pigeons became as skilled as humans at discriminating cancerous from healthy tissue.
Levenson RM, Krupinski EA, Navarro VM, Wasserman EA (2015). Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images. PLoS ONE 10(11): e0141357.