Sikkim Treecreeper Certhia discolor

Dark treecreeper with a warm rusty tail, thin white brow and mustache, and a gray chest. Warm tones on the tail contrast sharply with the cooler brown on the back and wings. Inhabits broadleaf and mixed forests, where it usually forages at the middle and upper levels. Unlike other treecreepers in the region, gives a long rapid-fire rattling trill instead of a series of high whistles and twitters.