some properties of spheniscidae make them potentially very suitable for intensive exploitation by patagonian hunters: they are easy to hunt, have a higher economic yield than other birds in the region, and are spatially predictable during the long breeding season, when they remain on land. however, the archaeological record of the atlantic coast of patagonia suggests little or no exploitation at all of spheniscidae breeding colonies throughout the holocene. nonetheless, taphonomic observations in the region have provided indications that there is a high probability of archaeological materials found with modern bird remains. spheniscidae remains at sites in cabo blanco (santa cruz, argentina) are among the few bone assemblages of these birds that have been recovered in archaeological deposits from continental patagonia. a taphonomic analysis is presented here, aimed at assessing the integrity (sensu binford 1981) of these deposits. furthermore, the need for a rigorous estimation of all the agents and processes taking part in the formation of penguin bone assemblages in the region before attempting interpretations of past human behavior is examined.