To cap off the PLOS ONE 10 Year Anniversary collection series, we decided to focus our efforts on the PLOS ONE Editorial Board – a sizable group of accomplished scientists that has allowed us to
A house is not a home without a dog, and a dog isn’t a “D-O-double-G” without its microbial “crew.” Human microbiome research is progressing rapidly, and we are always learning how the bacteria living on and inside of us contribute … Continue reading
The post Who Let the Microbes Out: A Paw Print of Doggy Skin Bacteria appeared first on EveryONE.
In the spirit of Thanksgiving and sharing a warm meal with loved ones, we’d like to take a moment to give some social credit to our loving, faithful, and clever furry friends. Researchers have been investigating the question of whether animals can eavesdrop—or listen in on third-party interactions—for some time, and evidence of potential eavesdropping has been identified in dogs and other mammals, fish, and birds.
Dogs are especially good candidates for studying eavesdropping because they are social animals and have been domesticated, so they are accustomed to interacting with humans day-in and day-out. Most dog owners know how well their dogs can “read” them, and some might argue that their dogs can do this better than other people they know. Researchers have also confirmed that dogs can recognize human emotions, facial expressions, and friendliness versus hostility, the latter even in strangers.
In a more nuanced form of social interaction, dogs have been shown to prefer certain people over others depending on the outcome of third-party interactions. To further investigate how dogs respond to interactions among people, the authors of this recently published PLOS ONE article asked whether dogs can develop a preference for or against givers, or “donors,” in a “begging” interaction between people.
The study recruited 72 dogs of various breeds and sizes and put them in a testing environment that either resembled a home or a dog care facility. While the dog watched from across the room, two human assistants acted as “donors” (females, pictured above) who offered food to a “beggar” (male, above), and the beggar either reacted positively or negatively to the offered food. The extent of the reaction was controlled to try to determine which social cues the dog was picking up on: gesture + verbal (GV), gesture only (G), or verbal (V) only.
In the GV group positive scenario, the beggar received a yummy corn flake, ate it, and said “So tasty!”; in the negative scenario, the beggar said “So ugly!” gave the corn flake back, and then turned his back. The G and V groups differed in that they isolated the gesture and verbal components, respectively. After the beggar left, the dog was released and had 10 seconds to decide between the donors, who did not signal the dog in any way. Dogs that did not make a choice were removed from the analysis.
As the results below show, dogs were more likely to choose the donor who received a positive reaction; the authors also noted that the dogs tended to watch or gaze at the donor who received a positive reaction longer than the donor who received a negative reaction. However, the authors state that both gesture and verbal cues (the GV group) were required to show a reliable difference among the groups.
Although these results alone are not conclusive, as it is difficult to control for all the variables affecting these scenarios (e.g., the authors note that dogs chose randomly if the donors switched places), the authors suggest that the dogs may have attributed a “reputation” to the donor based on the beggar’s reaction, where both gesture and verbal cues were required for the dog to make this association.
While not the same as a scientific experiment, it might be fun to “test” your dog in various eavesdropping scenarios, especially in relation to available food* on the Thanksgiving table.
Happy Thanksgiving from PLOS ONE!
Citation: Freidin E, Putrino N, D’Orazio M, Bentosela M (2013) Dogs’ Eavesdropping from People’s Reactions in Third Party Interactions. PLoS ONE 8(11): e79198. doi:10.1371/journal.pone.0079198
*food safe for pets to eat, of course!
While the tale of how man’s best friend came to be (i.e., domestication) is still slowly unfolding, a recently published study in PLOS ONE may provide a little context—or justification?—for dog lovers everywhere. It turns out that even thousands of years ago, humans loved to share food with, play with, and dress up their furry friends.
In the study titled “Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices,” biologists, anthropologists, and archaeologists joined forces to investigate the nature of the ancient human-dog relationship by analyzing previously excavated canid remains worldwide, with a large portion of specimens in modern-day Eastern Siberia, Russia. The authors performed genetic analysis and skull comparisons to establish that the canid specimens were most likely dogs, not wolves, which was an unsurprising but important distinction when investigating the human-canine bond. The canid skulls from the Cis-Baikal region most closely resembled large Siberian huskies, or sled dogs. Radiocarbon dating from previous studies also provided information regarding the dates of death and other contextual information at the burial sites.
The researchers found that the dogs buried in Siberia, many during the Early Neolithic period 7,000-8,000 years ago, were only found at burial sites shared with foraging humans. Dogs were found buried in resting positions, or immediately next to humans at these sites, and their graves often included various items or tools seemingly meant for the dogs. One dog in particular was adorned with a red deer tooth necklace around its neck and deer remnants by its side, and another was buried with what appears to be a pebble or toy in its mouth.
By analyzing the carbon and nitrogen in human and dog specimens in this region, the researchers were able to determine similarities in human and dog diets, both of which were rich in fish. This finding may be somewhat surprising because one might assume that dogs helped humans hunt terrestrial game, and would consequently be less likely found among humans that ate primarily fish.
The authors speculate that dogs were considered spiritually similar to humans, and were therefore buried at the same time in the same graves. The nature of the burials and the similarities in diet also point toward an intimate and personal relationship, both emotional and social, between humans and their dogs—one that involved sharing food and giving dogs the same burial rites as the humans they lived among. Ancient dogs weren’t just work animals or hunters, the authors suggest, but important companion animals and friends as well.
Citation: Losey RJ, Garvie-Lok S, Leonard JA, Katzenberg MA, Germonpré M, et al. (2013) Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices. PLoS ONE 8(5): e63740. doi:10.1371/journal.pone.0063740
Image Credits: Losey RJ, Garvie-Lok S, Leonard JA, Katzenberg MA, Germonpré M, et al. (2013) Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices. PLoS ONE 8(5): e63740. doi:10.1371/journal.pone.0063740
Siberian husky photo by Pixel Spit