Proteins from ancient frozen canine feces have been extracted for the first time ever to reveal more details about the diets of Arctic sled dogs and their relationship to people.
“The breakthrough could help scientists better understand our ancestors and what they fed their dogs as well as how dogs’ gastrointestinal health has evolved,” says UBC anthropologist Dr. Camilla Speller, senior author of the international study released today in Proceedings of the Royal Society B Biological Sciences.
“The recovered proteins reveal that the sled dogs consumed muscle, bone, intestines and roe from a range of salmon species including Chinook, Sockeye, Coho and Chum,” says Dr. Speller.
The so-called “paleofeces” dates back at least 300 years. It had been frozen in Arctic permafrost in the Nunalleq archaeological site, near Quinhagak, Alaska. The researchers say the paleofeces were so well-preserved that odour was present when the feces were broken in half.
“The lives of dogs and their interactions with humans have only recently become a subject of interest to archaeologists. This study of their dietary habits reveals more about their relationship with humans,” says lead researcher Anne Kathrine Wiborg Runge, a PhD student at the University of York.
“In the Arctic, dogs rely exclusively on humans for food during the winter but deciphering the details of provisioning strategies has been challenging,” says Wiborg Runge.
The presence of salmon roe in the paleofeces also sheds light on the time of the year in which the paleofeces were deposited and points to the summertime since salmon spawn in the fall.
“The dogs may have been fed differently or less frequently in summer, or been let loose to fend for themselves,” adds Wiborg Runge. “Working sled dogs are a particularly expensive resource, requiring up to 3.2 kg of fish or meat every day and provisioning of dogs would therefore have played a significant role in the food procurement strategies of past Arctic culture.”
The researchers used paleoproteomics, a technique based on tandem mass spectrometry (LC-MS/MS) to recover proteins from the fecal samples. Unlike more established or traditional analyses, proteomics can provide insight into which tissues the proteins originated from and makes it possible to identify which parts of animals were consumed.
Complementary analyses were performed with Zooarchaeology by Mass Spectrometry (ZooMS), an analytical approach pioneered at the University of York, on bone fragments recovered from within the paleofeces. This technique uses the collagen protein preserved in archaeological and historic artifacts to identify the species from which it derives.
The University of York, University of Copenhagen, the University of Aberdeen and the Qanirtuuq Incorporated village corporation were also part of the research project, which was funded by EU Horizon 2020, Danish National Research Foundation, and the UK Arts and Humanities Research Council.