The ability of hummingbirds to detect sugar-rich nectar allows them to occupy a distinct ecological niche, but the basis for this adaptation was unknown. Maude Baldwin, Stephen Liberles and colleagues (Science 345, 929–933, 2014) have now used comparative genomics and functional studies to determine how hummingbirds perceive sweet taste. In most vertebrates, the ability to detect savory and sweet tastes is mediated by specialized G protein–coupled receptors (T1Rs), with T1R1-T1R3 heterodimers responding to savory compounds and T1R2-T1R3 heterodimers responding to sweet compounds. The authors analyzed the T1R gene repertoire of hummingbirds in comparison to other vertebrates and found that hummingbirds, like other bird species, lack genes encoding T1R2 receptors. They then performed functional studies and found that hummingbird T1R1-T1R3 heterodimers, unlike chicken or swift T1R1-T1R3 heterodimers, could respond to several sugars. They further analyzed T1R3 protein chimeras and identified a 19-amino-acid segment in hummingbird T1R3 that was sufficient to confer sensitivity to sucrose. Similarly, they also found evidence that hummingbird T1R1 has undergone adaptive changes contributing to the perception of sweet taste. Together, these findings indicate that hummingbirds have acquired adaptive changes in T1R1 and T1R3 that have altered their ligand specificity to allow the detection of sugars.