Resumen

The genus Hylophilus sensu lato was recently recognized as polyphyletic and split in to several genera, including the monotypic genus Tunchiornis. We describe in detail the nesting features of T. ochraceiceps that could provide additional evidence to support the split of the genus. Nests were found at two stations in southwestern Perú, Manu National Park. We found three cup-nests covered externally with green moss and internally with thin and light straw fibers, with inner and outer major and minor axes of 48.6 × 49.2 mm and 66.6 × 61 mm, respectively, a wall thickness of 9.8 mm, and an inner depth of 38.7 mm. The eggs were creamy-white with dark-brown spots concentrated at the base and measured 18.3 ± 0.4 × 13.1 ± 0.3 mm with a mass of 1.73 ± 0.12 g. Overall nest attentiveness was 64% and the egg were incubated at 32.35 ± 3.11 °C. The incubation and nestling period lasted 15 and 11 days, respectively. The nest materials used by Tunchiornis are similar to Hylophilus but differ from Pachysylvia, which use dried leaves and bark. These results advance our understanding of the reproductive biology of this phylogenetically divergent group.