New insights on the breeding biology of the Cinnamon Tanager ( Schistochlamys ruficapillus ) in Brazil

The breeding biology of the Cinnamon Tanager (Schistochlamys ruficapillus) remains to be fully understood. The present study investigates it both in Arcos, Minas Gerais, and Quebrangulo, Alagoas, Brazil, between 1987 and 2021. Following the identification of an active nest, subsequent observations were conducted at three-day intervals from a concealed location. We found a total of 23 S. ruficapillus nests: 13 in Arcos, where breeding occurred between August and February, and 10 in Quebrangulo where breeding occurred between December and March. The nests were open cups, weighing 15.8 g, and measuring 8.2 × 12.4 cm, on average. The clutch size averaged 1.62 eggs, which measured 24.7 × 17.0 mm and weighed 3.2 g. They were of a greenish color with reddish-brown spots. The incubation period was 14 days, and the nestling period was 13 days. The apparent nest success was 26.09%. Both parents fed the nestlings berries, fleshy seeds, and insects and cleaned the nestlings’ excrement. Brood parasitism by the Shiny Cowbird (Molothrus bonariensis) was observed in four nests, with the parasite’s nestlings being fed more frequently than the host’s in one of them. The results of the present study are consistent with those obtained for other closely related species.