The white-rumped tanager (Cypsnagra hirundinacea) is a South American bird in the tanager family Thraupidae. It is the only member of the genus Cypsnagra.
The length is 16 cm with a weight of 25-34 g. They occur mostly in Brazil, also in Paraguay, Bolivia and Suriname at an elevation of 700–1000 m. They inhabit grasslands with few trees. In Brazil they are found in territorial groups of three to six individuals. They eat insects on the ground in the grass or catch them in flight (sallying). Their diet mostly consists of beetles, crickets and grasshoppers but they occasionally eat fruit. The cup shaped nests are placed only 1–2 metres off the ground and are made of woven grasses. The clutch is 3-4 blue eggs which are speckled around the large end with brown or black spots. Helpers born the previous season help mating pair tend the nest and nestlings.
The taxonomy is a little complicated. The white-rumped tanager was formally described in 1823 by German naturalist Hinrich Lichtenstein under the binomial name Tanagra ruficollis.[1] Unfortunately, this combination had been used in 1789 by German naturalist Johann Friedrich Gmelin for what is now a subspecies of the Greater Antillean bullfinch with the trinomial Melopyrrha violacea ruficollis.[2] [3] [4] In 1831 the French naturalist René Lesson described the white-rumped tanager and introduced the name Cypsnagra (as a subgenus) and the binomial name Tanagra hirundinacea.[5] The type location is Franca in the state of São Paulo in Brazil.[3] The genus name Cypsnagra is a mixture of the Ancient Greek kupselos meaning "swallow" and the genus name Tanagra. The specific epithet is from Modern Latin hirundinaceus meaning "swallow-like".[6]
Two subspecies are recognised:[4]