Dressed-Up Donkey Discovered at Religious Burial Site

Even in bygone eras, domestic animals were essential for the development of human civilization. Aside from their use as a primary food source, animals served as companions, hunters, protectors, and workers. However, they also participated in rituals and religious ceremonies, sometimes even deserving their own burials (animal mummies!). By analyzing the remains at discovered animal burial sites, archaeologists can learn a lot about human society during a specific era.

In a recently published PLOS ONE paper titled “Symbolic Metal Bit and Saddlebag Fastenings in a Middle Bronze Age Donkey Burial,” researchers describe the unprecedented discovery of a ritualized donkey burial, where the donkey had both a metal horse bit in its mouth and saddlebag fastenings on its back. Researchers determined that the donkey was carefully placed in the particular position, with limbs bent, as shown above, evidence of a purposeful burial. This specimen was dated to the Middle Bronze Age III (that’s roughly 1700/1650-1550 BCE) and found in a religious precinct at Tel Haror, an archaeological site in Israel.

This find is exciting because it indicates early use of harnessing/bridling equipment and a significant technological advance over using neck ropes, rings, or nose bands for steering pack animals. Through different types of analysis, the researchers shed light on the functional and symbolic roles of the donkey. Most notably, it appears that the burial and tacking were largely symbolic (nonfunctional) and part of a ceremonial ritual, which may have been followed by a feast involving other animals, whose bones were found nearby.

The researchers reached this conclusion based on a few key pieces of evidence. Dental analysis revealed that the donkey was sacrificed at a young age, about four years old. No wearing was evident on the teeth, meaning that it was probably never trained as a draught animal. In addition, the metal horse bit seems to have been pieced together, defective, and missing any adjoining bridle components when it was placed in the donkey’s mouth, suggesting that it would not have been used for actual labor. Finally, the saddlebags were smaller than usual; the researchers suspect that they were made specifically for the burial.

Understanding how humans utilized equid pack animals, especially donkeys, is important for identifying social, economic, and technological developments during earlier eras. In this case, it seems that the donkey’s role was largely one of high symbolic value, rather than functional, which may be related to the high social status that was attached to owning and riding donkeys at the time.

Citation and Images:

Bar-Oz G, Nahshoni P, Motro H, Oren ED (2013) Symbolic Metal Bit and Saddlebag Fastenings in a Middle Bronze Age Donkey Burial. PLoS ONE 8(3): e58648. doi:10.1371/journal.pone.0058648

Animal Heartbreakers? Animals, Behavior, and “Love”

Animal emotion remains a fairly contentious area of scientific research, but there is a growing body of evidence to support the idea that nonhuman animals can have feelings. The scientific community may not be ready to use the “L” word for animals, but we are beginning to understand that they do form relationships that are both more complex and insightful than they initially appeared.

While the birds and the bees don’t pre-order roses online or bust out heart-shaped boxes of chocolate for Valentine’s Day, many animal species—yes, even insects and spiders—exhibit courtship behavior to woo their mates (singing mice, anyone?). On the opposite end of the spectrum, animals can also be sneaky and engage in promiscuous behavior that rivals the latest plotline from your favorite soap opera. The physical, chemical, mental, and emotional drivers behind these behaviors are still under active investigation by the scientific community, and we have a few handy examples published in PLOS ONE.

In “Heaven It’s My Wife! Male Canaries Conceal Extra-Pair Courtships but Increase Aggressions When Their Mate Watches,” male domestic canaries, known to be socially monogamous, altered their courtship behavior toward females depending on the audience. Males were generally more aggressive with females around than with males or no one present. Males also courted other females more if their mates weren’t around, which the authors suggested may imply that there are costs (“divorce”) associated with courting other females while a mate watches. Tsk, tsk.

While canaries may be coy, some of our closest relatives display some of the fiercest aggressive and competitive behavior. In the recently published “Till Death (Or an Intruder) Do Us Part: Intrasexual-Competition in a Monogamous Primate,” owl monkey pairs were broken up by intruding “floater” monkeys, which in some cases, resulted in serious consequences for the ousted monkey: disappearance or death. These breakups also had a negative effect on the reproductive success of both the male and female monkey in the pair. Lasting monogamous owl monkey couples produced 25% more offspring than monkeys with two or more partners.

Are animals always heartbreakers? In what researchers consider an act of monogamy, pair-bonded California mice in this study refrained from scent marking when given the opportunity. This may not seem like a proud display of love and loyalty, but in the animal kingdom, scent marking can be a form of advertising for new females. The researchers also found that virgin male mice still participated in scent-marking behavior, providing further evidence that the other animals’ restraint was related specifically to pair bonding.

Just as we see behavioral differences in the animal kingdom, there’s certainly a lot of variety in human love and relationships. Regardless, we’d like to wish you all a happy Valentine’s Day!


Hanson JL, Hurley LM (2012) Female Presence and Estrous State Influence Mouse Ultrasonic Courtship Vocalizations. PLoS ONE 7(7): e40782. doi:10.1371/journal.pone.0040782

Panksepp J (2011) Cross-Species Affective Neuroscience Decoding of the Primal Affective Experiences of Humans and Related Animals. PLoS ONE 6(9): e21236. doi:10.1371/journal.pone.0021236

Ung D, Amy M, Leboucher G (2011) Heaven It’s My Wife! Male Canaries Conceal Extra-Pair Courtships but Increase Aggressions When Their Mate Watches. PLoS ONE 6(8): e22686. doi:10.1371/journal.pone.0022686

Fernandez-Duque E, Huck M (2013) Till Death (Or an Intruder) Do Us Part: Intrasexual-Competition in a Monogamous Primate. PLoS ONE 8(1): e53724. doi:10.1371/journal.pone.0053724

Image credit:

Monkey image, M. Corley/Owl Monkey Project

Graph, PLOS ONE paper, doi:10.1371/journal.pone.0053724

The Downside of Sharing: Winter Bugs

Unfortunately, increasing numbers of us are experiencing this year’s particularly brutal seasonal flu (most frequently influenza A, subtype H3N2). The CDC’s latest FluView report and US map show that nearly all states have widespread outbreaks, and these reports don’t include the other winter illnesses that typically plague us, like the common cold, bronchitis, and pneumonia.

As we arm ourselves with flu shots, alcohol hand rub, tissues, and disinfecting wipes, these stats also remind us to please cover our mouths when coughing and sneezing, and to stay home if we feel even the mildest of sniffles coming on. Peak flu season is usually in January or February, and in the wake of this epidemic, we’d like to draw attention to our rapid-peer-review journal, PLOS Currents Influenza, which has an ongoing call for submissions in research related to the 2012-2013 seasonal influenza outbreak.

Now that you’ve triple-wiped down your keyboard, mouse, and phone, let’s have a look at some winter-illness-related research articles published in PLOS ONE within the past year.

Have you ever wondered why flu outbreaks always seem to occur during the winter months in the first place? A paper titled “Relationship between Humidity and Influenza A Viability in Droplets and Implications for Influenza’s Seasonality” may shed some light on the matter: listen to a featured podcast about this article in Scientific American, posted just last month. In this study, researchers investigated the relationship between humidity, a characteristic that can vary with temperature, and the viability and transmissibility of influenza A virus droplets. Researchers suspended the virus in different media and found that it didn’t survive as well when conditions were salty, or when the humidity was between 50 and 98%. However, the virus was extremely viable in mucus, and at conditions below 50% (dry) or above 98% (almost tropical), the virus was also quite viable and happy. The results of this research may explain why influenza outbreaks are prolific in both dry, cold weather as well as tropical environments.

For those of you that haven’t yet been convinced to run out and get a flu shot (cough, shown to be 60% effective, cough), you may be interested in a paper published last summer, showing that at least certain types of flu, like H1N1, may be transmitted before any clinical symptoms are noticeable. The study, “Transmission of a 2009 H1N1 Pandemic Influenza Virus Occurs before Fever Is Detected, in the Ferret Model,” finds that sick ferrets placed close to healthy ones could spread the flu by contact or droplet exposure a whole day before any clinical symptoms appeared. Interestingly, coughing and sneezing had less to do with transmission than did the viral concentration in the ferrets’ noses. Additionally, after day five or six of illness, viral transmission significantly decreased, supporting the idea that it may be safe to return to school or work after the worst of the illness has passed.

A recently published paper describes an investigation into the motivations behind Americans’ tendency to not get flu shots, a behavior that has been troubling and puzzling to both doctors and scientists alike. In “Behavioral Responses to Epidemics in an Online Experiment: Using Virtual Diseases to Study Human Behavior,” researchers created an “infectious disease outbreak” game in a virtual multiplayer online world to study how willing people were to protect themselves during epidemics. Players accumulated points depending on their health status and actions they took, but they needed to spend points to protect themselves and thereby reduce their chances of falling ill. Results indicated that a person was more willing to take self-protective action when the outbreak was severe, or when a prior experience with inaction had resulted in illness. Players were also more likely to take preventative measures if they were less costly, which indicated to researchers that decreasing the cost of the flu shot could ultimately decrease the overall prevalence of the disease.

These articles are just a tiny droplet in the bucket of influenza-related research published in PLOS ONE. Click here to read more research articles on one of the more common types of seasonal flu, the influenza A virus.

And, please stay safe and healthy in these remaining winter months!

Image credit:  the H3N2 virus, ID#13470, CDC


Yang W, Elankumaran S, Marr LC (2012) Relationship between Humidity and Influenza A Viability in Droplets and Implications for Influenza’s Seasonality. PLoS ONE 7(10): e46789. doi:10.1371/journal.pone.0046789

Roberts KL, Shelton H, Stilwell P, Barclay WS (2012) Transmission of a 2009 H1N1 Pandemic Influenza Virus Occurs before Fever Is Detected, in the Ferret Model. PLoS ONE 7(8): e43303. doi:10.1371/journal.pone.0043303

Chen F, Griffith A, Cottrell A, Wong Y-L (2013) Behavioral Responses to Epidemics in an Online Experiment: Using Virtual Diseases to Study Human Behavior. PLoS ONE 8(1): e52814. doi:10.1371/journal.pone.0052814

A rockin’ good time at AGU

Last week the American Geophysical Union (AGU) Fall Meeting was held just down the road from our San Francisco office, and PLOS staff could not pass up the opportunity to make an appearance.

If you were an exhibition hall attendee and could manage to tear yourself away from all the talks, poster sessions, and workshops long enough to pay us a visit, you would have been met with friendly staff from both PLOS ONE and PLOS Currents Disasters, all on a mission to inform as many geophysicists as possible about open access and our various journals. We thoroughly enjoyed spending the week there and meeting any PLOS readers, authors, editors, and reviewers that stopped by to say hello. In particular, our publications manager Krista Hoff was excited to meet and have a chat with one of our longstanding Academic Editors, Ben Bond-Lamberty.

In an little bit of contrast to our recent visit to the Annual Meeting of the American Society of Human Genetics, many passersby did not immediately recognize the PLOS name. They were similarly unaware of our status as a nonprofit, our commitment to open access, and our relatively unique publication criteria. These conversations led to an exciting opportunity for us to explain that we publish in all areas of science, and especially to show our love to the worlds of geology, physics, chemistry, and environmental science.

While free pens were flying off the table, we had stimulating conversations with seismologists, planetary scientists, climatologists, geologists, and environmental scientists. Our rapid-peer-review journal PLOS Currents Disasters was extremely well-received among researchers associated with earthquakes or other chemical and geological hazards (including potential meteor disasters!).

Many scientists found our printed Open Access guide “How Open Is It?” both helpful and informative, and several were big proponents of open-access journals, excited to find that we accept submissions in geophysics research.

Long-time PLOS supporters were thrilled to inform us that they intended to submit at least one paper within the next year, and we definitely piqued the interest of at least a few potential reviewers and academic editors. We had some great discussions about barriers to scientific publishing in general and received insightful suggestions for improving the overall publication experience. We appreciated hearing everyone’s feedback and will be sure to incorporate your suggestions into our future discussions.

Look out for the PLOS booth again in just a few days at the American Society for Cell Biology, where we hope to see yet another side of our growing and diverse PLOS community!

Photo credits: U.S. Geological Survey Photographic Library