Avian remains from a new quaternary site (Marmot Cave) in the NW Altai, Siberia, located very close to the famous Denisova Cave, have been studied. The fauna from Marmot Cave includes 19 extant taxa, three of which were not reported previously from Denisova Cave. Taphonomic analysis of the bird bones from the new site indicates a mixed origin for the material. The largest portion of bones evidently represents remains not eaten by large falcons, while a small part of the sample may be the prey of the Golden Eagle. Bones of the Black Grouse are of anthropogenic origin and apparently were brought to Marmot Cave from the human settlement of Denisova Cave. The faunal composition suggests a Holocene age for the sediments of Marmot Cave, which is in contradiction with data from mammal remains. Copyright © 2013 John Wiley & Sons, Ltd.