A Yawn & Man’s Best Friend

By Erin Gellings

There’s nothing quite like the feeling of coming home after a long hard day and being welcomed by your dog. Many things dogs do are in response to their owners’ actions, including comforting and mimicking actions like yawning. There are many theories about why humans and other animals yawn, but no one theory has been proven 100% correct. What causes dogs to yawn in response to seeing a human yawn though?

Yawning Dog. Image by Scientre from Wikimedia Commons

This was the question Silvia Karine and Bessa Joana from the Universidade do Porto in Portugal set out to examine. The researchers found preliminary evidence that simply the sound of a human yawn and their relationship with their owner is enough to make a dog yawn.

Sometimes, when dogs are under stress, they can do something called a ‘tension yawn.’ There is still little evidence that explains why dogs yawn when experiencing stress. The best way to know if a dog is yawning due to feeling stressed, or in response to a human is to look at the environment. If the dog is in a new setting with new people, it is likely yawning due to stress. Researchers were very careful to make sure all the yawns dogs produced were genuine and not stress related. This was partly achieved by allowing dogs to become used to researchers before being introduced to audio of yawns. They made this determination by carefully reviewing what events led up to the dog’s yawn.

Karine and Joana used 29 dogs of various breeds and let each one become acclimated to them by just sitting in the dog’s home for about 10 minutes before they started the experiment. The researchers then exposed them to four conditions: a prerecorded sound of their owner’s yawn, familiar control sounds from their home, a stranger’s yawn, or control sounds not from their home. Each dog experienced the prerecorded sounds in a random order during two different sessions. A researcher played the sounds through a large set of speakers from audio files from a laptop in the dog’s home. The researcher wrote down every time the dog yawned, and also made a video recording of the dogs listening to the sounds so other researchers could go back and double check that their count was correct.

Twelve of the twenty-nine dogs yawned during the experiment. Out of the dogs who yawned, more dogs yawned at the yawning audio than at the background audio. This leads us to believe that the sounds of yawning are contagious and the dogs “caught” the yawn. The researchers also found that dogs yawned more when listening to the yawn of their owners than of strangers.

Aside from showing that dogs tend to yawn after hearing a human yawn, this research also hints that there may be some sort of social variable in why dogs yawn more at their owner’s yawn. The researchers suggest this may be related to a sense of empathy dogs feel towards humans, but this claim needs more research in order to be demonstrated. This research also showed that dogs do not necessarily need a visual cue of seeing a person yawn in order to yawn on their own. This is a claim that is unique to this particular project. While this research is still in its early stages, it does give us a new perspective on why dogs may yawn when around humans, and what leads to this unique behavior.

Although this study does not help us understand the function of yawning in dogs, it does bring us closer to understanding why dogs yawn in response to humans and sets the stage for future research in the field. So, after your next long day when you sit down and yawn and notice your dog yawn too, take a moment to appreciate the connection they have with you.


References

Finlay, K. (2017, June 15). Why do dogs yawn? American Kennel Club.

Silva, K., Bessa, J., & De Sousa, L. (2012). Auditory contagious yawning in domestic dogs (Canis familiaris): First evidence for social modulation. Animal Cognition, 15(4), 721-724.

Why do I yawn? (2019).

Not Fair! Even Dogs Know the Importance of Gift-Equity

A repost of an original article from December 2012.

Don't leave out your best friend when
gift-giving this holiday season!
Photo by Ohsaywhat at Wikimedia.

When I was a child, I think one of the things that stressed my mom out most about the holidays was making sure that all of us kids got Christmas gifts worth the exact same amount. Why all the fuss? Because if the value of the gifts wasn’t equal, we were guaranteed to spend our holidays in a chorus of “Not fair!” cries rather than appreciating the holiday bounty and cheer around us.

As a species, we have a pretty developed sense of fairness. This sense of fairness is central to our ability to cooperate to achieve goals that are too difficult for one person to accomplish alone. But we’re not the only social species that cooperates… and it turns out, we’re not the only ones with a sense of fairness, either.

Domestic dogs and their wild relatives, like wolves and African wild dogs, are very social and have cooperative hunting, territory defense, and parental care. Friederike Range, Lisa Horn, Zsófia Viranyi, and Ludwig Huber from the University of Vienna, Konrad Lorenz Institute, and Wolf Science Center, all in Austria, sought out to test whether domesticated dogs have a sense of fairness.

The researchers tested pairs of dogs who had lived together in the same household for at least a year. All of these dogs had been previously trained to give their paw on command, as if giving a handshake. Each pair of dogs was asked to sit in front of an experimenter (one dog was designated the “subject” and the other was the “partner”). In this position, the willingness of the subject dog to shake paws with the experimenter was tested under six different situations.

An experimenter asks two dog-buddies to each give her a paw and they wait
to see who gets rewarded. Photo from Range et al., PNAS, 2009.

In the basic situation, both dogs were asked to give a paw, and both dogs were rewarded with a “low-value” reward (a piece of bread). This happened repeatedly and the researchers measured how many times the subject dogs would give their paw.

In another situation, both dogs were asked to give a paw, but the subject dog was rewarded with a “low-value” reward (a piece of bread) while its buddy was rewarded with a “high-value” reward (a piece of sausage).

In a third situation, both dogs were asked to give a paw, but only the partner dog was rewarded with a piece of bread (the subject dog got nothing).

In the fourth situation, only the subject dog was asked to give a paw, but both dogs were rewarded with a piece of bread.

In the fifth situation, the experimenter measured how many times the subject dog would give its paw for a piece of bread if his doggy-buddy wasn’t around.

In the last situation, the experimenter measured how many times the subject dog would give its paw for no reward if his doggy-buddy wasn’t around.

When both dogs received bread, they were happy to keep giving the experimenter their paw for as long as they were asked to. But when dogs saw their buddy get a piece of bread when they got nothing, they soon refused to give their paw to the experimenter (and started showing signs of stress). You may think this is just what happens when you stop rewarding a dog for doing what you ask, but something different was going on here. The dogs that never got a reward gave their paw to the experimenter for longer when their buddy wasn’t around than if their buddy was around and getting bread treats. Clearly, even dogs know that equal work for unequal pay is not fair.

But the doggy-sense-of-fairness is limited. As long as they got their bread when they gave their paw, they really didn’t seem to care (or notice) if their buddy got bread or sausage, or even whether their buddy had to perform the same trick or not.

So this holiday season, don’t forget to get a present for your four-legged friend so he doesn’t feel left out. But don’t worry about getting something expensive – He doesn’t care anyway. For him, it’s the gesture that counts.

Want to know more? Check these out:

1. Range F, Horn L, Viranyi Z, & Huber L (2009). The absence of reward induces inequity aversion in dogs. Proceedings of the National Academy of Sciences of the United States of America, 106 (1), 340-5 PMID: 19064923

2. Range, F., Leitner, K., & Virányi, Z. (2012). The Influence of the Relationship and Motivation on Inequity Aversion in Dogs Social Justice Research, 25 (2), 170-194 DOI: 10.1007/s11211-012-0155-x

Caught in My Web: Perplexing Animal Behaviors

Image by Luc Viatour at Wikimedia Commons.

Sometimes animals behave in such an odd manner, that even the animal behaviorists aren't sure what the heck they are doing or why. So for this edition of Caught in My Web, we just wonder.

1. Last month, a dog was hit and killed by a car. His fellow doggy-companion then used his nose to bury him. Was this a funeral? Is this just canine burying behavior? We don't know, but it's been seen before. This video is from 2013:

And here is another from 2015:

2. Have you seen this video of turkeys circling a dead cat?

3. An African elephant approaches a white rhino with a branch across his nose. Was he trying to play or was he bring aggressive? Either way, the rhino wasn't taking any chances. Watch the exchange here.

4. A South American Magellanic penguin swims 5,000 miles every year to be reunited with the man who saved his life. Read the heartwarming story here.

5. An octopus inflates itself like a giant balloon across the ocean floor and scientists can't agree if it is hunting or showing defense behavior. What do you think?

Caught in My Web: All About Dogs

Image by Luc Viatour at Wikimedia.

For this edition of Caught in My Web, we celebrate our wonderful canine companions.

1. Nina Golgowski at HuffPost Science explains research that shows that dogs give treats to their doggy friends, but not to doggy strangers.

2. Rafael Mantesso's wife left him and took everything but the dog and the empty white apartment. Rafael found inspiration in his predicament and created some of the most wonderful photos ever! Check them out here.

3. Let puppies teach you about complexity theory in this TED talk by Nicolas Perony.

4. Virginia Hughes at National Geographic shares research that shows that dog brains process voice information similarly to our own.

5. And just for fun, here is Bella the dog singing “Jingle Bells”:

Caught in My Web: The Intelligence and Creativity of Crows, Octopuses, Monkeys, Fish and Dogs

Image by Luc Viatour at Wikimedia.

For this edition of Caught in My Web, we marvel at animal intelligence.

1. Joshua Klein talks about crow intelligence and their potential for training in this fun TED talk.

2. Jason Goldman at io9 explains an amazing discovery that Atlantic cod can also innovate to solve problems.

3. Sarah Williams at Science explains research out of Harvard that shows that untrained rhesus monkeys can do math and we can use this to learn about how we think.

4. A veined octopus shows off his imagination as he creates a “hiding” place:

5. And last, but not least, three shelter dogs were taught to drive! Here are the results:

How Fashion Destroyed My Best Friend (A Guest Post)

By Sarah Johanson

“Bulldog Portrait Frank”. Image by Pharaoh Hound at Wikimedia.

Man’s Best Friend is a title that has been passed onto our four-legged, drooling counterpart. Dogs have been at man’s side for a number of years showing us his dedication and protection. In the 19th Century, humans started breeding dogs as a hobby. Today, humans have created more than 400 breeds, with less than 200 being recognized by the American Kennel Club, and all can be traced back to the same canid ancestors similar to the gray wolf. As humans selectively bred dogs based on their physical appearances to make a fashion statement, beneath the skin genetic and physiological changes where happening that would have a far harsher consequence to dogs’ health. One such breed is the English Bulldog.

All dog breeds have what are known as breed standards that are set by the Kennel Club or the American Kennel Club. These standards dictate what the breed should look like physically. At first, dogs were bred on a guideline of form follows function. Bulldogs were bred to help butchers control bulls in the slaughter yard. They had long snouts with strong jaws, necks and shoulder muscles while also being tall, allowing them to be quick and agile. However, during the fashion era of dog breeding in the 19th century, breeding became more of a hobby for physical appeal rather than for the dog to have a purpose… which brought us the bulldog we see today.

Head Comparison of a Bulldog (bottom)
and that of a Labrador Retriever (above).
Bulldog image “Camilla, the english bulldog,”
by Trevomeisel at Wikimedia. Labrador
image and edits done by Sarah Johanson.

Over time, the bulldogs’ upper jaws and snouts have been shortened by a significant amount, giving them those mushed short faces. They were bred this way because people thought they looked cute. This shortening is caused by a genetic mutation which causes a developmental defect during bone formation. It’s thought the defect became prevalent due to severe inbreeding. This shortening of the upper jaw has led to there not being enough space in bulldogs’ mouths. Their tongues and palates are often compressed, with the teeth on their lower jaws protruding out in odd directions as their teeth don’t fit, leading to problems with eating and chewing food.

Bulldog nostrils have also been compressed to the point that they can barely breathe. If a human were to breathe like the bulldog, it would be like breathing through a straw. Having a small airway has led the bulldog to become easily overheated and exercise intolerant. To cool down most dogs pant, using water as a tool to take heat away with it as it evaporates. Due to the soft palates not being able to fit in the dogs’ mouths and the narrowing of their throats, panting interferes with breathing. This leads to the production of foam, which blocks the airways even more, sometimes causing suffocation.

Bulldogs are also unable to mate on their own or give birth successfully. Due to their short, stocky bodies, very wide shoulders and narrow pelvises, most males cannot breed with the female on their own. The female either needs to be attached to a breeding stand which gives her body support in order to bear the male’s weight or she needs to be artificially inseminated. Furthermore, a natural birth is almost impossible as the puppies’ heads are too large to fit through the breed’s narrow pelvis to leave the body. This condition, known as dystocia, causes over 80% of bulldog births to be performed via caesarian section. Almost all bulldog births need some kind of human assistance; otherwise they would risk the life of the mother and her unborn puppies.

Diagram of bulldog body shape demonstrating how the “box head” of the breed cannot fit through
the pelvic bone (triangle) during birth due to size and shape. Image created by Sarah Johanson.

These are only some of the physical challenges bulldogs face, not to mention all of the medical problems that could follow. It has been the selective breeding done by breeders and the breed standards set that have turned this dog from the power it once was to the mess that it is today. The bulldog became a fashion statement and although he continues to want to please his human counterpart, his body cannot keep up with his desire.


Work Cited:

Baldwin Bulldog. “Bulldogs Overheat.” Baldwin Bulldogs, 10 Dec. 2014. Web. 23 Feb. 2015.

Denizet-Lewis, Benoit. “Can the Bulldog Be Saved?”nytimes.com. The New York Times, 22 Nov. 2011. Web. 5 Feb. 2015.

Dog Breed Health. “Bulldog (English Bulldog).” Dog Breed Health, n.d. Web. 6 Feb. 2015.

Dogtime. “A Brief History of Breeding.” Dogtime, 30 May. 2009. Web. 5 Feb. 2015.

Kalmanash, Angela. “The Physiology and Morphology of a Breed Standard” DogChannel. DogChannel, 9 June. 2014. Web. 5 Feb. 2015.

Thomson, Keith Stewart. “Marginalia: The Fall and Rise of the English Bulldog” American Scientist. 84(1996): 220-223. Web. 7 Feb. 2015.

Dogs Have Co-opted Our Physiology to Win Our Hearts

Photo by Roberto Ferrari at Wikimedia Commons.

Why do we feel genuine love and friendship for our dogs? The social relationship between humans and dogs is not just special, it is downright AMAZING! Domestic dogs are the only species that we know of that will spontaneously respond to cooperative human gestures, such as pointing or gazing in a specific direction, without any training or prior experience. Wolves and even non-human great apes require extensive experience with people to understand these human gestures. Dogs, on the other hand, are so naturally in-tune with our gestures that they, like human children, are likely to interpret eye contact as communicative, even when it is not. New research has found that eye contact between ourselves and our canine companions may fuel an interspecies physiological feedback loop that keeps our two species living as best friends.

Today at Accumulating Glitches, I am exploring new research about how our four-legged best friends change our brain physiology so we will love and care for them more. Check out the full story here. 

And this is why we love our dogs so much:

Further reading:
MacLean, E.L. and Hare, B. Dogs hijack the human bonding pathway, Science, 438:6232, 280-281 (2015). DOI: 10.1126/science.aab1200

Nagasawa, M., Mitsui, S., En, S., Ohtani, N., Ohta, M., Sakuma, Y., Onaka, T., Mogi, K.., and Kikusui, T. Oxytocin-gaze positive loop and the coevolution of human-dog bonds, Science, 438:6232, 333-336 (2015). DOI:10.1126/science.1261022

Cooperating for Selfish Reasons

An Ethiopian Wolf photographed by Gert Vankrunkelsven.
Image available at Wikimedia.

If you were a young adult Ethiopian wolf, you would have a choice to make: Should you be a member of a monogamous breeding pair or a helper to an already established breeding pair (who are probably your parents)? The choice seems obvious, right? I mean, who wants to be a helper? Why should you forgo all the glory and status of being part of the breeding pair to be a babysitter?

Today I am revisiting my thoughts on the motivations to cooperate from an article I wrote in the early days of The Scorpion and the Frog. You can read the article in it's entirety here.

Caught in My Web: Creepy Animals, Animal Disguises, Pet-Love After Death, and Ebola

For this Halloween edition of Caught in My Web, we check out what the web has to say about creepy animal stories.


1. The CDC addresses questions about whether pets can get ebola

2. Julie Hecht, the author of Dog Spies at Scientific American blogs explores the love between dogs and their owners from beyond the grave

3. BuzzFeed presents 8 surprisingly creepy animals.

4. Dr. Doolittle at ScienceBlogs talks about the eyeless Mexican cavefish

5. Sara Mynott at Saltwater Science, a blog at Nature’s Scitable blog network, explains flounder disguises (they’re not just for Halloween)

Is That Lizard Possessed!? (A Guest Post)

By Tawny Liebe

Image from Chuck Heston on Flickr.

A creature straight from the depths of hell… or at least as close as you can get on this planet. The Texas horned lizard or “horny toad” is found in the deserts of the southwest United States and has an unusual adaptation to deter predation exclusively from a few species of canines. When threatened by coyotes, foxes, and dogs, the horned lizard squirts blood from its eyes to hit targets up to three feet away! A total of six species of horned lizard have been proven to respond this way to canine attack, while none have responded this way to other predators, such as the grasshopper mouse or the roadrunner. So what is the deal? How do they do this and how does it work as predator defense?


Veins have one-way valves
to prevent backflow.
Drawing by Tawny Liebe.

Before we get to that, there are a few things you need to know. First of all, the circulatory system includes a network of arteries and veins. Arteries carry blood full of oxygen to body tissues while veins carry blood that lacks oxygen from the rest of the body back to the heart. This means that for the blood, in someone’s foot for instance, to get all the way back to the heart through the veins, the blood must work against gravity. When you (or this lizard or many other species) move, blood is propelled from one chamber in the vein to the next until it reaches the heart. The blood is prevented from flowing back into the previous chamber by one-way valves, causing the blood to pool.

In order to squirt blood from their eyes, horned lizards manipulate the network of veins in their head so that they build up pressure, like a volcano getting ready to blow. By constricting a pair of throat muscles unique to reptiles, they effectively close their jugular veins and increase the blood pressure in their head. This is thought to be enhanced by another pair of muscles between the jugular veins and the eyes that help increase the blood pressure in the head even further, causing the blood to move into the sinuses of the eyes. The pressure continues to build until the blood breaks through the wall of the eye socket into the eyelids where it is forced into the tear duct and erupts like a Mentos in a Coke bottle all over whatever is chomping at the poor little lizard.

As if these lizards couldn’t get any more amazing, recent studies have shown that it is actually a compound in their blood that canines don’t like. Scientists have also found that this chemical is in their circulating blood, not just the blood that is squirted from their eye, rejecting an earlier hypothesis that the chemical is picked up in the tear duct. To top off all of this awesomeness, the chemical may be acquired through its main food source- harvester ants, which are venomous. These ants aren’t actually a requirement of the horned lizard’s diet and yet they are specialized to eat them. The horned lizard’s blood plasma binds to the venom, which neutralizes its toxicity and the resulting compound may be what deters these canines.

Now that we know how horned lizards are capable of this type of defense and how they most likely make their blood so undesirable, what is it about this chemical that is so appalling to these predators? It appears that the target area of the blood is the mouth since the horned lizard only squirts the blood when the canine begins to bite down on its head. This suggests that it may be the taste of the blood that prevents the horned lizard from becoming that coyote’s tasty snack.

The horned lizard’s ability to squirt blood at canines to prevent their untimely death is truly amazing and complex and there is still much to learn about it. Their ability makes me wonder how many other cool anti-predator adaptations there are out there in the animal and even the plant kingdom! Below is a video that will allow you to appreciate the full effect of this awesome defense strategy, enjoy!

References:

Heath, J.E. 1966. Venous shunts in the cephalic sinuses of horned lizards. Physiological Zoology 39(1): 30-35.Middendorf, G.A. and Sherbrooke, W.C. 1992. Canid elicitation of blood-squirting in a horned lizard (Phrynosoma cornutum). Copeia 1992(2): 519-527.

Middendorf, G.A. and Sherbrooke, W.C. 1992. Canid elicitation of blood-squirting in a horned lizard (Phrynosoma cornutum). Copeia 1992(2): 519-527.

Middendorf, G.A. et. al. 2001. Comparison of blood squirted from the circumorbital sinus and systemic blood in a horned lizard, Phyrnosoma cornutum. The Southwestern Naturalist 46(3): 384-387.

Middendorf, G.A. and Sherbrooke, W.C. 2004. Responses of kit foxes (Vulpes macrotis) to antipredator blood-squirting and blood of Texas horned lizards (Phrynosoma cornutum). Copeia 2004(3): 652-658.

Sherbrooke, W.C. 1992. Chiricahua Mountains Research Symposium. Horny “toad” tales from the Chiricahua mountains as, told by a biologist. Southwest Parks and Monuments Association, Tuscon, AZ. 78-80.

Caught in My Web: The Secret Lives of the Animals Around Us



Image by Luc Viatour at Wikimedia.

Most of us are surrounded by animals that we take for granted every day. We see them sleep and eat and clean themselves, and then sleep again. But our pets and yard-critters have secret and interesting lives. This week in Caught in My Web, we explore some of the lesser-known secrets of the animals around us.

1. Your dog poops in alignment with the Earth’s magnetic field.

2.  Your cat is just using you.

3. Some of the fish in your fish tank may change sex:

4. The birds at your birdfeeders have personalities, and some are liars.

5. Squirrels are the masters of… well, just about everything.

What Does the Fox Say?

Image by Rotfuchs at Wikimedia.

In early September, two brothers that host a popular late-night talk show in Norway released a music video to promote their show’s season premiere. Those brothers form the comedic duo called Ylvis, and the song: “What Does the Fox Say?”. A complete surprise to the Ylvisåker brothers (their last name), who designed their video as a comedic music video flop, their video went viral. It spent three consecutive weeks as number 6 on Billboard Hot 100 and is quickly approaching 300 million views in just over three months!

The premise of the song is that there are a number of animals whose sounds everyone knows, but the fox stumps us. As their lyrics go:

Dog goes woof, cat goes meow.
Bird goes tweet, and mouse goes squeak.
Cow goes moo. Frog goes croak, and the elephant goes toot.
Ducks say quack and fish go blub, and the seal goes ow ow ow.
But there's one sound that no one knows...
WHAT DOES THE FOX SAY?

…And then it gets weird as they propose their thoughts on what sounds foxes make:

The funny thing is, it’s not that hard to find out what sounds foxes really make. Although they may not be among the common farm and zoo animals that make it into our children’s toys and books to teach us all about the world of animals, fox vocalizations have been studied by scientists for years. Strangely enough, our comedic duo was not that far off with their “Jacha-chacha-chacha-chow!” guess, which is similar to the fox gekkering call used in aggressive interations.

“The Fox” video (as it has come to be known) has spawned countless spoofs in the last few months. As with most internet spoofs, most are pretty lame, but there are a few gems. My favorite, created by some talented Harvard Medical School students, addresses the equally perplexing question “What Does the Spleen Do?” (Which we also know the answer to. Check out the end of the video for the true answer).

Caught in My Web: What Your Dog Really Thinks About You, Understanding Gestures, Camera Traps and Pruney Fingers

Image by Luc Viatour at Wikimedia Commons.

This week in Caught in My Web, I share what I found when pondering interactions between humans and animals, what we have learned from camera traps, and what our pruney fingers in the bath may have to teach us about our animal nature.

1. Greg Berns, a psychiatry professor at Emory University, set out to use an fMRI scanner to learn more about what dogs think about their humans. Read his story here at Psychology Today. And check out this video describing The Dog Project:

2. Although dogs may be “man’s best friend”, they have failed numerous tests in understanding our gestures, such as pointing, without training. Even chimpanzees require training before understanding the meaning of human pointing. But elephants are now the first non-human species that seems to innately understand human pointing, naturally investigating objects pointed to (comparable to a 1-year-old human). Jack Flanagan discusses this research at NewScientist.

3. At The Thoughtful Animal, Jason Goldman discusses camera traps (weather-resistant cameras that use motion detection sensors to photograph wildlife) and how they are used in animal research. He also reveals the secret ingredient to luring jaguars to the cameras at You’ll Never Guess How Biologists Lure Jaguars To Camera Traps.

4. While we’re talking about camera traps, Siberian tiger researchers set up camera traps in southeastern Russia. One of their cameras took a series of 3 amazing pictures of a golden eagle attacking a sika deer. Check out the pictures at National Geographic.

5. Ever wonder why your fingers get pruney in the bath? Maybe it is a primate adaptation! Mark Changizi explains why at TEDEd:

Caught in My Web: Food vs. Sex, Recording Vibrations, Genital Distractions, Singing Dogs and Extreme Vision

Image by Luc Viatour at Wikimedia

This week will be the first of a new feature: Caught in My Web, a collection of recent articles, blog posts, videos and more that shed light on interesting aspects of animal physiology and behavior.

 

1. There is often a tradeoff between food and sex. The Schneider Lab talks about the physiology of at what point a male will leave a meal to search for sex in Should I Stay or Should I Go? on the blog Sexandfoodand. To make things more interesting, the critters discussed are the nematode worms, C. elegans, and males are not seeking sex with females, but rather with hermaphrodites. And as a bonus, this article includes the best Harlem Shake video of all time!



2. If you liked my article, Interrupting Insects, on how male treehoppers use vibrations to court females, you’ll love this first-hand account of what it is like to do this kind of research! In his blog Missouri Historian, Micah Fletcher, Micah recounts his experience studying these critters in Eavesdropping on a Silent Symphony.



3. In ScienceNow, Helen Fields tells us how hawk moths giggle their genitals to prevent bats from catching and eating them in ScienceShot: Vibrating Genitals may Ward off Predators. A word of caution: If you are being chased by a hungry predator, try this at your own risk!



4. In Expedition to Find the New Guinea Singing Dog: The Rarest Dog in the World in Running Ponies at Scientific American Blogs, Becky Crew interviews James ‘Mac’ McIntyre, a field zoologist planning an expedition to find and study the world’s most elusive dog species.



5. And just for fun, here’s a video on extreme animal vision by Steve Rotfield Productions.

Do Animals Have Personalities?

Leaders and followers. What makes personality? Photo by Thang Nguyen at Wikimedia Commons.

The heart of science lies in existential questions such as "Who am I?" and "Where did I come from?" Yet somehow, these are the very questions that scientists tend to shy away from. It's as if we're afraid that by unraveling the mysteries of our world and ourselves, we'll be left with nothing but a handful of yarn. But many of us see the quest for personal understanding differently - as a journey to gain appreciation for all the complexities and rare events that came together to weave the glorious tapestry that is life. It is in this push and pull of wanting to know more while still wanting to maintain mystery that the study of personality lies. And for this reason (and many others), the science of personality has been woefully understudied and underappreciated.

This week I am at Accumulating Glitches pondering personality: What is it? How do we study it? And do other animal species have it? Check it out here.

And to learn more, check these out:

1. Réale, D., Reader, S., Sol, D., McDougall, P., & Dingemanse, N. (2007). Integrating animal temperament within ecology and evolution Biological Reviews, 82 (2), 291-318 DOI: 10.1111/j.1469-185X.2007.00010.x

2. Huntingford, F.A. (1976). The Relationship between anti-predator behavior and aggression among conspecifics in the three-spined stickleback, Gasterosteus aculeatus Animal Behaviour, 24, 245-260

3. Sinn, D., Moltschaniwskyj, N., Wapstra, E., & Dall, S. (2009). Are behavioral syndromes invariant? Spatiotemporal variation in shy/bold behavior in squid Behavioral Ecology and Sociobiology, 64 (4), 693-702 DOI: 10.1007/s00265-009-0887-2

Do Non-Human Animals Like Human Music?

We think of song as an artistic expression, a beat to groove to, a melodic story. But to animals that use it (arguably including many birds, whales, and primates), “song” is generally a competitive vocal signal used to attract mates and deter rivals. This leaves us wondering: Do any non-human animals have music? Can they even enjoy human music? Some certainly seem to:


A Cockatoo Shakes His Tailfeather:

 

A Beluga Whale Listens To A Mariachi Serenade:

A Dog Grooves To His Buddy's Guitar:

What do you think? There is evidence that some animals enjoy singing themselves, but can non-human animals appreciate human music? What is it about rhythms and melodies that we humans appreciate anyway and can the ability to appreciate music improve an animal’s (including our own) chance of survival?

It turns out, some researchers have tackled these questions. But that, my friends, is for another post.

Not Fair! Even Dogs Know the Importance of Gift-Equity

Don't leave out your best friend when
gift-giving this holiday season!
Photo by Ohsaywhat at Wikimedia.

When I was a child, I think one of the things that stressed my mom out most about the holidays was making sure that all of us kids got Christmas gifts worth the exact same amount. Why all the fuss? Because if the value of the gifts wasn’t equal, we were guaranteed to spend our holidays in a chorus of “Not fair!” cries rather than appreciating the holiday bounty and cheer around us.

As a species, we have a pretty developed sense of fairness. This sense of fairness is central to our ability to cooperate to achieve goals that are too difficult for one person to accomplish alone. But we’re not the only social species that cooperates… and it turns out, we’re not the only ones with a sense of fairness, either.

Domestic dogs and their wild relatives, like wolves and African wild dogs, are very social and have cooperative hunting, territory defense, and parental care. Friederike Range, Lisa Horn, Zsófia Viranyi, and Ludwig Huber from the University of Vienna, Konrad Lorenz Institute, and Wolf Science Center, all in Austria, sought out to test whether domesticated dogs have a sense of fairness.

The researchers tested pairs of dogs who had lived together in the same household for at least a year. All of these dogs had been previously trained to give their paw on command, as if giving a handshake. Each pair of dogs was asked to sit in front of an experimenter (one dog was designated the “subject” and the other was the “partner”). In this position, the willingness of the subject dog to shake paws with the experimenter was tested under six different situations.

An experimenter asks two dog-buddies to each give her a paw and they wait
to see who gets rewarded. Photo from Range et al., PNAS, 2009.

In the basic situation, both dogs were asked to give a paw, and both dogs were rewarded with a “low-value” reward (a piece of bread). This happened repeatedly and the researchers measured how many times the subject dogs would give their paw.

In another situation, both dogs were asked to give a paw, but the subject dog was rewarded with a “low-value” reward (a piece of bread) while its buddy was rewarded with a “high-value” reward (a piece of sausage).

In a third situation, both dogs were asked to give a paw, but only the partner dog was rewarded with a piece of bread (the subject dog got nothing).

In the fourth situation, only the subject dog was asked to give a paw, but both dogs were rewarded with a piece of bread.

In the fifth situation, the experimenter measured how many times the subject dog would give its paw for a piece of bread if his doggy-buddy wasn’t around.

In the last situation, the experimenter measured how many times the subject dog would give its paw for no reward if his doggy-buddy wasn’t around.

When both dogs received bread, they were happy to keep giving the experimenter their paw for as long as they were asked to. But when dogs saw their buddy get a piece of bread when they got nothing, they soon refused to give their paw to the experimenter (and started showing signs of stress). You may think this is just what happens when you stop rewarding a dog for doing what you ask, but something different was going on here. The dogs that never got a reward gave their paw to the experimenter for longer when their buddy wasn’t around than if their buddy was around and getting bread treats. Clearly, even dogs know that equal work for unequal pay is not fair.

But the doggy-sense-of-fairness is limited. As long as they got their bread when they gave their paw, they really didn’t seem to care (or notice) if their buddy got bread or sausage, or even whether their buddy had to perform the same trick or not.

So this holiday season, don’t forget to get a present for your four-legged friend so he doesn’t feel left out. But don’t worry about getting something expensive – He doesn’t care anyway. For him, it’s the gesture that counts.

Want to know more? Check these out:

1. Range F, Horn L, Viranyi Z, & Huber L (2009). The absence of reward induces inequity aversion in dogs. Proceedings of the National Academy of Sciences of the United States of America, 106 (1), 340-5 PMID: 19064923

2. Range, F., Leitner, K., & Virányi, Z. (2012). The Influence of the Relationship and Motivation on Inequity Aversion in Dogs Social Justice Research, 25 (2), 170-194 DOI: 10.1007/s11211-012-0155-x

Cooperating For Selfish Reasons

If you were a young adult Ethiopian wolf, you would have a choice to make: Should you be a member of a monogamous breeding pair or a helper to an already established breeding pair (who are probably your parents)? The choice seems obvious, right? I mean, who wants to be a helper? Why should you forgo all the glory and status of being part of the breeding pair to be a babysitter? 

The Governess painted by Rebecca Solomon in 1851 shows a modestly-dressed
Victorian era governess (in black) who diligently cares for the education needs of
her employer's young children, while the well-dressed employer is free to flirt.
Image provided by Wikimedia.

But Ethiopian wolves often do make that choice. These wolves are territorial rodent hunters and their survival and success depends on how many giant mole rats (their favorite food) and Murinae rats (a second-choice food-option) are available in the territory. In territories with fewer rodents, Ethiopian wolf families are likely to consist of a mother, a father, and their pup born that season. However, in territories with lots of rodents available, wolf families also include some of the older siblings from previous years. Why do they stick around?

An Ethiopian Wolf photographed
by Gert Vankrunkelsven.
Image available at Wikimedia.

Jorgelina Marino, Claudio Sillero-Zubiri, Paul Johnson, and David Macdonald from the University of Oxford in the U.K., set out to ask this question. They collected data on 17 wolf packs in the Bale Mountains of southern Ethiopia for 13 years. They did this by following the packs on foot or on horseback and watching them with binoculars. The researchers also mapped the quality of the habitats to estimate the number of giant mole rats and Murinae rats available.

These wolf packs included 13 wolf packs with territories in optimal rodent-hunting areas (high-quality habitat in the Web Valley-Sanetti area) and 4 packs with territories with very few rodents (poor-quality habitat in the Tullu Deemtu area). The packs in the high-quality habitat had from 3-13 wolves, usually including the breeding pair, their pup, their adult sons from previous years and some of their adult daughters from previous years (Adult daughters were more likely to set out on their own than the sons). The packs in the poor-quality habitat only had 2-3 wolves, including the breeding pair and maybe their pup.

The researchers discovered that the small packs generally had large but poor-quality territories. The wolf packs in high-quality habitats had smaller habitats, but the bigger the pack, the bigger their territory and the more high-quality habitat they had on their territory. This may be because for each additional wolf in the pack, the more hunting territory is needed to support it. But the researchers discovered that these large wolf packs had more high-quality territory per wolf than the smaller packs had. So if you were a young adult Ethiopian wolf, you would have more high-quality hunting territory for you if you were to choose to stay home with mom and dad and your other siblings than if you were to seek a mate of your own.

Wolves that lived in the Tullu Deemtu area had small groups and large territories, but the
territories did not have a lot of access to food. Wolves that lived in the Web Valley-Sanetti
area had more access to food and could live in larger groups on smaller territories. The more
wolves in the pack in the Web Valley-Sanetti area, the more territory they could defend
per wolf.  Figure from Marino, Sillero-Zubiri, Johnson, and Macdonald's 2012 Behavioral
Ecology and Sociobiology paper.

The researchers also explored other possible advantages of group living, but didn’t find much. These animals hunt alone, so larger groups do not hunt more effectively than smaller groups. And the helpers were not all that helpful as babysitters either: The breeding pair did not have more pups, and pups were not more likely to survive, in families that had more helpers.

So the main advantage for a young adult Ethiopian wolf to stay home with mom and dad a bit longer seems to be more access to better hunting grounds. Why would this be? Ethiopian wolves patrol the boundaries of their territories and pee on them to mark their territory. More wolves in the pack means more patrols and more pee. In this way, larger packs are more able to defend more and better-quality territory. This benefits each of the young adults that stay with the family, and even mom, dad and pup too… to a point. Once the pack reaches a size of 8 adults, the benefits per wolf decline. Packs larger than 8 are more likely to split into multiple smaller packs, each with its own breeding pair. One more benefit of being in a larger group: When young adults split off from the family pack to establish their own breeding pair, they often get to inherit some of their natal territory.

If you find yourself living with mom and dad later than you may have anticipated, it may just be worth it as long as the refrigerator stays stocked and the diggs are comfortable. And if you find yourself a mom or dad with an adult child living with you later than you may have anticipated, it may just be worth it as long as they help stock the fridge and keep the place clean. But as soon as the arrangement stops being beneficial for everyone, it is time to strike out on your own.

Want to know more? Check this out:

Marino, J., Sillero-Zubiri, C., Johnson, P.J., & Macdonald, D.W. (2012). Ecological bases of philopatry and cooperation in Ethiopian wolves Behavioral Ecology and Sociobiology, 66, 1005-1015 DOI: 10.1007/s00265-012-1348-x