Rather nuthatch-like, this unique species is actually a Furnarid (Ovenbird) and is apparently related to Earthcreepers and Xenops. Endemic to Chile and adjacent Argentina, the White-throated Treerunner is a Beach Forest specialist. Protruding tail-feather shaft-spines are used like a woodpecker to prop itself up against tree limbs. The scaly pattern on its underparts are reflected in its generic name which means "wicker basket" in Greek. Canon PowerShot SX50 HS.
References:
Remsen, J.V., Jr (2018). White-throated Treerunner (Pygarrhichas albogularis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/56593 on 15 February 2018).
White-throated Treerunner (Pygarrhichas albogularis), In Neotropical Birds Online (T. S. Schulenberg, editor). Cornell Lab of Ornithology, Ithaca, New York, USA. retrieved from Neotropical Birds Online: https://neotropical.birds.cornell.edu/Species-Account/nb/species/whttre2