Photographs of an unidentified shrike-tyrant at Lauca national park, Chile, November 2006. The streaked underparts suggest a juvenile. The bird was photographed in the same group of rocks as a pair of White-tailed had been seen two weeks earlier, but is it a juvenile White-tailed (plumage currently undescribed) or a juvenile Black-billed? (Is the bill going to get darker but remain th same size - or get larger and retain the pale lower mandible? Are the mantle colour and white throat streaking more reminiscent of White-tailed? Or does the head pattern suggest Black-billed?) Suggestions please!