The nest and nestlings of the Black-tailed Flycatcher, Myiobius atricaudus snethlagei (Passeriformes: Onychorhynchidae)

Abstract

The Black-tailed Flycatcher, Myobius atricaudus, is a Neotropical insectivorous bird species with seven recognized subspecies. This contribution focuses on M. a. snethlagei, a subspecies from northeastern Brazil that can be identified based on plumage characters. To our knowledge, information on the breeding of the Black-tailed Flycatcher is scarce and is restricted to the other two subspecies, M. a. atricaudus and M. a. ridgwayi. We describe an active nest observed on 15 February 2017 in the northeastern slope of the Araripe Plateau, Ceará State, Brazil. The nest containing two nestlings was a long and closed pensile structure, attached from the tip to a slender branch and suspended 89 cm over a small stream inside the forest. It had the following dimensions: outside height 41 cm, outside diameter 52.5 mm, inside height 62.9 mm, inside diameter 44.6 mm, and circular chamber entrance 43.6 x 31mm. The nest was mainly composed of long rootlets, strips of dried leaves, tendrils and some fine sticks. It was found in the Brazilian Caatinga’s Dry Forest during the rainy season, which does not correspond to the breeding period of birds in other localities of northeastern Brazil. Despite several similarities among the nests of M. a. atricaudus, M. a. ridgwayi and M. a. snethlagei, leaves and spider web were not observed among the materials used to build the nest of M. a. snethlagei. This might be a useful feature to differentiate between the nests of this species and the other subspecies. Furthermore, the nest description is consistent with the pattern of nest architecture known for the members of Family Onychorhynchidae.