Siberian Jay Perisoreus infaustus ranges across most of Eurasia, from Scandinavia to the Sea of Okhotsk. In China, opicus is in the Altai Mountains in Xinjiang and maritimus is in Heilongjiang. Lives inconspicuously in coniferous forests in the taiga zone, consuming insects and berries; stores balls of food in tree bark for consumption in winter. A small, long-tailed forest jay with fluffy, mainly dark-brown to greyish-brown plumage. Cap dusky-brown. Wing-coverts, rump, and sides of tail rusty-red. Greyish-brown plumage grades to rufous on flanks and undertail coverts. Bill short, black, with buffy tuft at base; feet black. Often silent, but has a wide repertoire of calls, including whistles and mews; accomplished mimic. Song a very quiet stream of whistles, mews, and twitters. — Craig Brelsford
Daniel Bengtsson served as chief ornithological consultant for Craig Brelsford’s Photographic Field Guide to the Birds of China, from which this species description is drawn.