Bone modification in the Arctic National Wildlife Refuge, Alaska (2010)

Skeletal bones and antlers from past generations of wildlife are frequently found and consumed by other animals, living out a second life as an important dietary resource. Such gnawing may leave characteristic modifications, including tooth marks, providing physical evidence of a behavior and nutrient resource that is often challenging to directly observe and quantify. Documenting and interpreting features of bone modification can fill knowledge gaps regarding species’ behavioral ecology, nutrient requirements, and interactions in modern ecosystems, as well as in historical, archeological, and paleontological contexts. While prior research has documented characteristic patterns of bone modification and gnawing for a variety of bone consumers, these studies generally focus on a single species or taxonomic group, with only limited comparison to bone modifications generated by co-occurring groups (i.e., ruminants vs. carnivorans vs. rodents). Cataloguing bone modifications at ecosystem-scales has rarely been the focus of past work, which may be partially responsible for a profound gap in existing knowledge regarding how co-occurring and competing bone consumers partition this shared source of nutrients (e.g., calcium, phosphorous, and calorie-rich marrow). We compiled available literature on bone modifications made by rodents, ungulates (specifically ruminants), and carnivorans. Using this compilation as a starting point, we characterized the full suite of modifications observed on shed antlers and skeletal bones collected during standardized bone surveys along the Coastal Plain of the Arctic National Wildlife Refuge (Alaska). In total, we described, summarized, and photographed 27 distinct classes of pits, punctures, scores, furrows and fractures, and, when possible, identified the taxonomic group that is known or likely responsible for each modification class. Seven of these classes, all attributed to ruminants (likely caribou), have not been previously described. This dataset includes every occurrence of the 27 modification classes observed on the 1,567 antlers and 224 skeletal bones collected from the Arctic National Wildlife Refuge. A unique strength of this dataset is that it includes the largest assessment of bone modifications on a single skeletal element (antlers), providing unparalleled opportunities to evaluate variability in bone modification across space (~200 kilometers) and through time (antlers can persist on tundra surfaces for hundreds to thousands of years). Detailed descriptions, images, and explanations of the most likely bone modifier (ruminant, rodent, carnivoran) associated with each of the modification classes can be found within Gaetano M, Miller J, Wald EJ, Druckenmiller P. in press The Atlas of Arctic bone modification. Ecol. Arch.