Tuesday, October 2, 2012

MPIG 2012: My First Poster Session!

Last weekend was my first time going to the Midwest Primate Interest Group (MPIG). I thoroughly enjoyed the academic experience, not to mention being able to meet fellow primatologists and those whose work I have read frequently but never met in person. I was also able to meet some friends that I've met online through blogs, Facebook and Twitter in person. So, in short, MPIG was a great academic experience and also a way for me to put a 3D sensory input on people I knew but never met. The podium talks were great and posters were very interesting. I only wish the poster session was longer so I could see all the posters that were submitted (there were 25 and I was only able to see 5!).

Getting ready to present our groundbreaking data!
MPIG also marked my first time presenting an academic poster. I was the co-author, with the illustrious Ashlee Van Schyndel (from This Is Serious Monkey Business) as the first author. Thanks to those that stopped by to look at our poster, and gave us important and useful constructive criticisms (and praises!). I have included the poster on the bottom of this post. So, what do you guys think? Any suggestions on how we can make a better poster in the future?

Below is the abstract of our poster:

Foraging preferences and substrate use in the absence of food availability pressures in three lemur (Lemur catta, Eulemur mongoz, and Eulemur sanfordi) species

A.A. Van Schyndel1 and Raymond Vagell2

1Lemur Conservation Foundation, Myakka City, FL and 2Department of Psychology, CUNY Hunter College, New York, NY 

Foraging behaviors are complex and is contingent upon the environment in which the organism lives. In situations where the ecological pressure of food availability is removed, individuals have the option of foraging based on preference. At the Myakka City Lemur Reserve in Myakka City, Florida, lemurs are semi-captive, free ranging, and provisioned. However, between the multiple lemur species in the free-ranging forests, there is an expected diversity in foraging preferences in terms of food choice and substrate use.  For this study, three species of lemurs were studied: ring-tailed lemurs (Lemur catta), mongoose lemurs (Eulemur mongoz), and Sanford’s brown lemurs (Eulemur sanfordi). A focal animal scan sampling and all occurrences sampling was completed over the course of two months that measured activity budget, food item choice, and substrate use. Results indicate there is a relationship between the niches inhabited by the lemurs in terms of substrate use and food item choice.

Please click on the image for a large file. If you would like a pdf version of our poster, please let me know

Wednesday, September 12, 2012

The Lesula: A New Species of Cercopithecus Described In The Democratic Republic of Congo

We have ourselves another new primate species. Yes, one whole new species that no one has seen before. Oh ... the native? They don't count. Just because they know of the existence of this primate species for years doesn't mean that it actually exists. It only exists when said species are described by science. Right? Of course not. I think we need to be careful when we talk about new species, especially media outlet that report these kinda stories. They are not "discovered", they are "described". Science (I'm using this in a broad sense) doesn't get to discover something if it's already known. Anyway ...

Left: Adult male Cercopithecus lomamiensis, Yawende, DRC. Photograph by M. Emetshu. Right: Subadult female Cercopithecus lomamiensis, Opala, DRC. Photograph by J. A. Hart.
Photos from Hart et al. (2012)

Hart et al. (2012) just published a paper in which they described a new monkey species known as the "lesula" to the locals. Their paper "Lesula: A New Species of Cercopithecus Monkey Endemic to the Democratic Republic of Congo and Implications for Conservation of Congo’s Central Basin" is available on PLOS ONE if you are interested in reading it (it's free access).

The lesula or Cercopithecus lomamiensis ranges in the Tshuapa, Lomami and the Lualaba (TL2) area of the Democratic Republic of Congo (DRC). They are found in the lowland rain forests of central DRC  C. lomamiensis belongs to the Cercopithecini family and is closely related to the Hamlyn's monkey or owl-faced monkey (Cercopithecus hamlyni). However, C. lomamiensis is genetically distinct from C. hamlyni as well as in morphology and vocalizations. C. lomamiensis has a lighter coat compared to C. hamlyni (see photos below). C. lomamiensis seems to have a light brown face while C. hamlyni a dark face with a white stripe on its nose.

Portraits: Captive adult male Cercopithecus hamlyni (upper left), photo by Noel Rowe, with permission; and captive adult male Cercopithecus lomamiensis (upper right), Yawende, DRC, photo by Maurice Emetshu. Lateral view: Hunter-killed adult male Cercopithecus hamlyni (bottom left), photo by Gilbert Paluku; and eagle-killed subadult female Cercopithecus lomamiensis (bottom right), photo by Gilbert Paluku.
Photos from Hart et al. (2012)
C. lomamiensis are semi terrestrial and subsist on terrestrial herbaceous vegetation (herbivory). And yes, to answer the burning question, both C. lomamiensis and C. hamlyni have blue perineum and scrotum. This is definitely interesting news, if not, an urgent call for conservation efforts in the DRC area. C. lomamiensis is the second new primate species to be described recently in Africa after the kipunji, Rungwecebus kipunji

Tuesday, September 11, 2012

Loris Awareness Week

Since September 16th is Loris Awareness Week, I'd like to call into attention the illegal primate pet trade that is getting worse and needs to be stopped. Primates are taken out of their natural habitat and illegally smuggled out to be turned into "cute" house pets. We won't be helping if we all think that primates make good pets and that you want to own one because "they are cute". Instead we should educate ourselves on why some animals are just not meant to be pets (adopt a shelter dog or cat instead!). Besides being turned into house pets, some primates are also taken from the wild so that they can be "movie stars". I implore you, my readers, to not support any movies or TV shows that use primates as animal actors. If you do not want to boycott the movie or show, at least understand why the only primate that should be actors are humans.

There are purportedly "cute" videos of slow lorises popping up on Youtube, in which, I generally watch in horror and disbelieve. I won't link any of these videos on this post but a quick search for "Tickling Slow Loris" would bring you to one such video. As a New Yorker, I only have one response to that video. "The slow loris is scared and is in a defensive posture, stupid!" But I digress. Besides being turned into pets, slow lorises are also hunted for traditional medicine.

Illegal Wildlife Trade fact sheet from  Dr Anna Nekaris's Little Fireface Project website
I wouldn't do any justice on these cute prosimians but head on to Dr Anna Nekaris's Little Fireface Project to read about her work on slow lorises and her team's effort to save slow lorises through better awareness and education.

Tuesday, August 28, 2012

Who Else Is Going To The Midwest Primate Interest Group (MPIG) Conference?

This September, the illustrious Ashlee Van Schyndel (of This Is Serious Monkey Business) and I will be presenting in a poster session at Midwest Primate Interest Group (MPIG) Conference. The conference will be held in Northern Illinois University, Dekalb, IL from Friday (Sept. 28th) till Saturday (Sept. 29).

Our poster topic will be on the foraging preferences (food choice and substrate use) in lemur species in the absence of food availability pressures. Ashlee collected her data at the Lemur Conservation Foundation in Myakka City, FL when she was a research assistant.

For more information about the conference, please visit the Midwest Primate Interest Group website. Hope to see y'all at the conference!

Monday, August 27, 2012

Primatologist's Log, Stardate 2012.27.08: I am finally taking an Anthropology/Primate Class

Primatologist's log, supplemental. For the first time in my graduate life, I have finally sat foot inside the Anthropology lab at Hunter College, CUNY for my Primate Ecology and Behavior class. I am elated to be finally back into my home range, namely the Anthropology department, for a primate class. Since I'll have a lot of primate materials to go through, hopefully I'll blog more this semester. Not promising anything though since I'm getting married in October and I am busy rehearsing to be a Bridezilla. Well, not really ... but kinda, really.

Tuesday, July 31, 2012

I'm a Vagell Now

I interrupt this long silence on my blog for some very important announcements.

First of all, sincere apologies to all my readers for the sporadic and lack of blog posts this year. I was playing catch up with life (I won!) so that rendered me with little to no time for blogging. Follow me on Twitter @PrancingPapio if you would like to follow me in real time, and also please Like my page, The Prancing Papio on Facebook.

I was recently naturalized as a United States citizen. This should open up better opportunities for grants should I want to apply for them in the future. Also, this means that travelling outside of the US will no longer be a pain in the bum. So if any one of you primatologist wants me to be your assistant, this is a good time to let me know ;)

With my naturalization and an impending wedding this October, I have decided to change my last name to Vagell. Not only am I taking my partner's last name, but I'm also tired of people mispronouncing my name for the past 30 years! I might or might not have revealed my age ... oh well. As we all adapt to me being referred to as Raymond Vagell or Mr. Vagell, let's just remember that I am no longer Raymond Ho or that horrid Chinese name that I was given but I shall not mutter.

So that's about it. I promise I'll start blogging more soon but now, I am knee deep in planning for my wedding and my honeymoon.

Saturday, June 9, 2012

Cannibalism in Gray Mouse Lemur: A Case of Hannibal Lemur

Gray mouse lemur (Microcebus murinus). Photo from Stanford University

See that cute guy up there? That's a gray mouse lemur (Microcebus murinus). Aren't they cute? Gray mouse lemur are arboreal mouse-like lemurs found on the island of Madagascar. They are nocturnal and are considered "cryptic species" because they come out at night. Gray mouse lemur are solitary when foraging but sleep in groups inside tree holes during the day. They are omnivorous, feeding mainly on vegetation, invertebrates and small vertebrates. Gray mouse lemurs can also hibernate during the cool months, a unique characteristic for primates. In recent years, wild gray mouse lemur are hunted and trapped for the pet trade. *Cue my PSA* Primates of any kind do not make good pets. While these gray mouse lemurs are cute, they are not meant to be pets.

The world of primatology is once again rocked to its core with the discovery of yet another primate species that cannibalize it's own kind. OK, well maybe it's not that serious but that's just a hook for you to continue reading my post.

Reports and observations of meat-eating in primate species have surfaced in recent years through published literature. Most of these primate species have never been observed predating on mammals (they usually eat invertebrates). While many know that chimpanzees occasionally eat meat, each chimpanzee subspecies have different hunting strategies and hunt specific prey species. Chimpanzees (Pan troglodytes schweinfurthii) from Gombe Stream National Park were observed hunting and eating red colobus monkeys (Colobus badius tephrosceles) by Dr. Goodall while western chimpanzees (Pan troglodytes verus) in Fongoli have been observed hunting and eating lesser bushbabies (Galago senegalensis) by Dr. Pruetz. Gomes and Boesch have reported that male western chimpanzees (P. t. veruswould also use meat to barter for long-term mating with females. Reports of meat-eating in Sumatran orangutans (Pongo abelii) had only surfaced as early as this year by Hardus et al. (2012). 

Of course, meat-eating is fundamentally different than cannibalism. Cannibalistic individuals eat the flesh of conspecifics. "Meat-eating" in literature generally refers to a meat consumption between heterospecific. In non-human primates, one of the explanations of cannibalism is thought to be a coping response with food scarcity. If food resources are scarce, both mother and offspring will die due to starvation. As a survival strategy, the mother would cannibalize her offspring (which will die soon anyway) as a way of returning the caloric investment back to the female. Juvenile and infant non-human primates are usually observed cannibalized by their mothers. I have covered maternal infanticide in Sumatran orangutans (Pongo abelii) and moustached tamarins (Saguinus mystax) in this blog, although many more primate species have been seen cannibalizing their own offspring.

This little gray mouse lemur is going to town with the carcass of an adult female conspecific. 

A recently published paper by Hämäläinen (2012) described a male gray mouse lemur (Microcebus murinus) cannibalizing an adult female conspecific. The author does not know how the female died, but posit that the female could have been killed by predators. However, since carcass of the female was not consumed, it is uncharacteristic for a predator to abandon its prey. The author also suggests that the male seen cannibalizing the female could not have been the predator since female gray mouse lemurs are more dominant than males.

On attempting the second focal session for this individual at 21:52 hr, I encountered her at the approximate same location as an hour earlier, but at this time I could see the reflection of the collar and approached to 10 m distance. I found that she was dead and her body was being fed on by a conspecific male. 
The carcass was hanging head down from a branch at 1.5 m elevation from the ground. At the time of discovery, the body cavity had been torn open and the internal organs eaten. The skull had also been broken and the brain consumed. Additionally, the flesh had been torn from one hind and one fore limb. The corpse was known to be fresh since the individual had been seen active earlier and when the body was recovered, rigor mortis had not yet set in. When sighted, the cannibalistic male was ferociously biting into the protruding spinal cord (Fig. 1, supplementary material) and continued feeding on the body (the spine, ribcage, and soft tissue) for approximately 20 min after sighting. 
After his departure, I collected the body and brought it into the field camp, where a veterinarian conducted an autopsy the following morning. The autopsy provided no further clues to the cause of death or the animal’s health status since all the vital organs were missing.

The author claims that this is the first ever reported cannibalism in gray mouse lemur and the first incident of adult conspecific cannibalism in non-human primates in literature. The significance of this discovery is not just that a gray mouse lemur is seen cannibalizing its own kind but in some way reflects the flexibility of their diet. This observation could also further elucidate the foraging strategies of this species. Gray mouse lemurs could have been scavengers but because they are a cryptic species, this behavior was never observed by scientists. The author posit that cannibalism might be an immediate way of accessing nutritional and energetic benefits, therefore is adaptive in the individual level.

For more about this paper, please see A Case of Adult Cannibalism in the Gray Mouse Lemur, Microcebus murinus by Anni Hämäläinen (2012) published on American Journal of Primatology (AJP). You can also read about it on Science, ScienceShot: Cannibalism Seen in Gray Mouse Lemur.

Friday, January 27, 2012

First Day Of Spring 2012 Semester

Things are going to get hectic again as I start another semester towards my Masters degree. I'm taking 3 classes this semester. While it doesn't seem to be a lot, there will be quite a number of readings and assignments needed to be done for these classes so I am perfectly happy graduating a year or one semester later if it means I get to keep my sanity in the process. Two classes that I look forward to this semester is Ethology, and Animal Welfare. Obviously, if you know me, you know I hate Math so having to take Statistics classes for 4 semester is absolute torture for me. I'm taking my 3rd Statistic class this semester (Blergh!).

I had my first class today in the Animal Welfare class. My professor asked us to draw an animal that represents  us, and why. So, I drew a hamadryas baboon (of course!). I like them because they are adaptable and they have a luxurious mane (only in males). Yes, I said luxurious mane. How gay is THAT?

Friday, January 20, 2012

Miller's Grizzled Langurs, thought to be extinct, have been rediscovered

More good news heading our way. Another primate who was thought to be extinct has now been rediscovered in the jungles of Borneo. Published in the latest edition of American Journal of Primatology, the Miller's Grizzled Langur (Presbytis hosei carnicrus) was rediscovered in Wehea Forest, an area outside of its known range. Thought to have gone extinct as early as 2004, subsequent expedition in 2008 in search of P.h. carnicrus was to no avail, supporting the hypothesis that this species had went extinct.

There was virtually no photographs of Miller's Grizzled Langurs except from museum sketches.
Illustration by Stephen Nash, from Mammals' Planet.

Call it the luck of the draw. The scientific team who photographed these langurs initially set up camera traps to take pictures of clouded leopards, orangutans and other critter that congregate on salt licks. Then they discovered that the camera traps had taken photos of langurs that they have never seen before. Until now, there was no photograph of this species ever in existence; only images from museum sketches. Based on these museum sketches, the team later confirmed that the langurs from the photos are indeed P. h. carnicrus.

Brent Loken, one of the lead researchers, was excited about this rediscovery, "We were all pretty ecstatic. The fact that, wow, this monkey still lives, and also that it's in Wehea ... While our finding confirms the monkey still exists in East Kalimantan, there is a good chance that it remains one of the world's most endangered primates".

A Miller's Grizzled Langur. Photo by Eric Fell, from EurekAlert!

A Miller's Grizzled Langur. Photo by Eric Fell, from EurekAlert!

 A video from Scientific American shows time-lapse photos of these langurs at the salt licks.

 For more, read:
'Extinct' monkey rediscovered in Borneo by new expedition on EurekAlert!
Extremely Rare Primate, Believed Nearly Extinct, Discovered in Remote Borneo Forest on Planet Save.
Nearly Extinct Primate Rediscovered in Borneo [Video] on Scientific American

The paper, titled "Discovery of Miller’s Grizzled Langur (Presbytis hosei canicrus) in Wehea Forest confirms the continued existence and extends known geographical range of an endangered primate" is supposed to have went live but I couldn't find it. I will update this page with a URL for the paper once it's available.

Thursday, January 19, 2012

Meat-Eating in Sumatran Orangutans

Caught in the act. Mother and infant Sumatran Orangutan sharing their kill, a slow loris.
Photo from NewScientist.
Well, well, well ... it seems like we have another great ape species who can't stay on a vegetarian diet. I mean, who in their right mind would want be an obligate herbivore right? Right? Actually ... contrary to popular belief, orangutans are not strictly frugivores (fruit eater). They also subsist on plant parts (leaves, buds, flowers, bark, sap, etc) and the occasional bird eggs and insects. Thus it came as to no surprise for me that some orangutans have acquired taste for meat. A varied diet is a good diet. A flexible diet in response to scarce food resources is an even better diet! Yes, I'm looking at you Giant Panda. Eat something else will ya? Edit: A rep from Giant Pandas did confirm that they do eat something else.

Sumatran Orangutans (Pongo abelii) are not the first great ape to have a taste for meat. Chimpanzees (Pan troglodytes schweinfurthii) from Gombe Stream National Park were observed hunting and eating red colobus monkeys (Colobus badius tephrosceles) by Dr. Jane Goodall while savannah chimpanzees (Pan troglodytes verus) in Fongoli have been observed hunting and eating lesser bushbabies (Galago senegalensis) by Dr. Jill Pruetz.

A new paper published in International Journal of Primatology, Behavioral, Ecological, and Evolutionary Aspects of Meat-Eating by Sumatran Orangutans (Pongo abelii)by Hardus et al. (2012) describes 3 rare cases of meat-eating by a mother and infant dyad Sumatran Orangutans. This pair was observed eating slow lorises (Nycticebus coucang), which the authors posit that meat-eating is a fallback strategy when food source (ripe fruits) are scarce. 

The authors also touched on very fundamental yet intriguing questions about meat-eating and hominid evolution in this paper. What are the minimum time on chewing is necessary for an adult female Australopithecus africanus to reach its daily energy requirement when subsisting partially on raw meat?  How did meat became a substantial component of hominid diet?

A. africanus needs 1202–1507 calories per day for their daily energy requirement. By using the chewing rate of P. abelii as a model, the authors estimate that A. africanus have to chew about 2 hours on raw meat to achieve 25% of their caloric needs while the remaining 75% were subsisted from easier to chew food sources such as leaves and insects.  Raw meat does not seem to be an efficient way to satisfy caloric needs but seemed to be a "fallback" resource when other food source are scarce. As to when meat became a substantial component of hominid diet, it is probably after the "discovery" of fire by Homo erectus. Cooked meat are easier to chew and provides more nutrient than from raw meat. The rate of mastication also decreases because most fibers within raw meat are broken down after it's cooked.

Tuesday, January 10, 2012

Images of Live Myanmar Snub-Nosed Monkey Finally Revealed

Two years ago, a new species of snub nosed monkey was described by scientists and was named Myanmar snub-nosed monkey (Rhinopithecus strykeri). When it was first described, there were no image of living specimen of this species in existence. The team who described this new species illustrated the new species based on field sightings and a dead carcass retrieved from a local village before it goes to the dinner table.

Myanmar snub-nosed monkeys. Illustrated based on field sightings and a dead carcass.
 Image from Martin Aveling/Fauna & Flora International.
Recently, researchers from Fauna & Flora International (FFI), Biodiversity And Nature Conservation Association (BANCA) and People Resources and Conservation Foundation (PRCF) were able to use camera traps to capture photos of these elusive monkeys from the mountains of Kachin State in Burma., near China.

The pelage of R. strykeri is entirely black except for a white tuft on their ears, chin beard and the perineal end. It has a relatively long tail, about 140% of its body. R. strykeri is the first species of the Rhinopithecus genus to be found in Myanmar. The other four species (R. roxellana, R. bieti, R. brelichi and R. avunculus) are found in China and Vietnam. R. strykeri's range is limited only to the Maw River area. There are estimated about 260 to 330 individuals of R. strykeri left in the wild, making them Critically Endangered according to IUCN.

Not much else is known about this elusive species besides some field sightings and knowledge from the locals. According to the locals, the upturned nose of these monkeys caused them to sneeze when it rains. This is a fatal giveaway because hunters are able to find the location of these elusive monkeys. To avoid getting rain water into their nose, R. strykeri would sit with their heads tucked in between their legs.

One of the images of Myanmar snub-nosed monkey captured by camera traps.
Photo credit: FFI/BANCA/PRCF
These images are surprisingly eerie especially since they are in black and white, and that these monkeys just seem so ... out of this world given that they have little to no nose (hence named snub nosed). Some have nicknamed these monkeys "Michael Jackson" monkeys, for obvious reason.

One of the images of Myanmar snub-nosed monkey captured by camera traps. Image shows what appears to be two adults and two offspring. Are these two adults mothers carrying their offspring?
Photo credit: FFI/BANCA/PRCF
There are more images of P. strykeri on the Huffington Post site:  Myanmar Snub-Nosed Monkey Photos Reveal Recently Discovered Primate

Sunday, January 8, 2012

New Mouse Lemur Species Described in Eastern Madagascar

Gerp's mouse lemur (Microcebus gerpi).
Photo by  Blanchard Randrianambinina from WildMadagascar.
There is evidence that a new mouse lemur species has been discovered in eastern Madagascar. While conducting survey and distributional data of mouse lemurs in the Sahafina Forest (inside Mantadia National Park) between 2008-2009, German scientists (Radespiel et al., 2011) came upon a mouse lemur species that is not only highly divergent in all molecular analyses from all previously described mouse lemur species but also differs morphologically from other species of mouse lemurs that live in the area.

Named after GERP (Groupe d'Étude et de Recherche sur les Primates de Madagascar), the newly described Gerp's mouse lemur (Microcebus gerpi) weighs in at about 2.4 ounces. The distribution of M. gerpi is not fully unknown but the researchers posit that their habitat is highly fragmented.

It's closest neighbor, the Goodman's mouse lemur (Microcebus lehilahytsara) is much smaller in size compared to M. gerpi. Goodman's mouse lemur was described in early 2007.

Goodman mouse lemur (Microcebus lehilahytsara).
Photo from Primatology.net.
For more, please read Tiny lemur discovered in Madagascar forest and the paper that described the new species by Radespiel et al. (2011).

Saturday, January 7, 2012

Contagious Yawning from Human to Domestic Dogs: Is It Possible? What Are The Implications?

Yawning is a phenomenon that occurs not only in human but also in other animals such as mammals, fishes, amphibians, reptiles and birds (Heusner, 1946; Baenninger, 1987; Gallup et al., 2009). There are many proposed reasons and functions as to what elicit yawning behavior in an individual but little is known about the role of contagious yawning and how animals can catch yawns from other species. Even though yawning is widespread in the animal kingdom, contagious yawning has only been reported in humans, chimpanzees (Pan troglodytes), stumptail macaques (Macaca arctoides) and recently in domestic dogs (Canis familiaris) (Provine, 1986; Platek et al., 2003; Anderson et al., 2004; Paukner & Anderson 2006; Joly-Mascheroni et al., 2008; Harr et al., 2008). In addition, studies have shown that there is a positive correlation in the susceptibility of contagious yawning with empathy and theory of mind (Platek et al., 2003; Preston & de Waal, 2002), and that emotional closeness and relatedness between an individual is key to eliciting contagious yawning in human (Norscia & Palagi, 2011).

Contagious yawning has been reported in humans, chimpanzees, stumptail macaques and  domestic dogs.
There have been many suggestions on the roles of contagious yawning, especially in primates. Some literatures hypothesized that contagious yawning in primates plays potential roles in communication, social interaction, empathy and self-awareness (Deputte, 1994; Daquin et al., 2001; Platek et al., 2003; Gallese et al., 2004; Platek et al. 2005) while others thinks that it is a stereotyped action behavior and an innate releasing mechanism (Provine, 1986). In addition, Platek et al. (2003) showed a positive correlation in the susceptibility to contagious yawning with self-face recognition and theory of mind stories while children with autism spectrum disorder showed an absence in contagious yawning (Senju et al., 2007) suggests that contagious yawning may be related to empathy (Preston & de Waal, 2002). A recent study on yawn contagion in human shows that related individuals (r ≥ 0.25) were the ones that are more susceptible to contagious yawning, and concludes that emotional closeness between an individual is key to contagious yawning in human as opposed to other variable such as sex or country of origin (Norscia & Palagi, 2011).

Although yawning is widespread in the animal kingdom, contagious yawning has only been reported in humans (Provine, 1986; Platek et al., 2003), chimpanzees (Anderson et al., 2004), stumptail macaques (Paukner & Anderson 2006) and domestic dogs (Joly-Mascheroni et al., 2008; Harr et al., 2008). Contagious yawning from human to domestic dogs  is interesting because it could further elucidate if empathy was inadvertently selected for in domestic dogs as they evolve side by side with modern humans. If yawns can indeed be passed from human to domestic dogs, we can posit that domestic dogs are capable of empathy. Further experiment on contagious yawning from the owner (human) to domestic dogs could also elucidate whether yawns are more susceptible based on emotional closeness as per Norscia & Palagi's (2011) research, albeit their subjects are all humans.

Neonatal macaque imitation the expression of a researcher.
Gallese et al. (2004) contended to the fact that mirror neurons play an integral part on the theory of mind and empathy. Later experiment by Iacoboni et al. (2005) posits that mirror neurons are involved in understanding the intention of others. By using an FMRI, human subjects were exposed to 3 types of stimuli on 24 second video clips. These stimuli show grasping hand action without a context (Action), context-only (Context), and grasping hand with and without context (Intention). In the Action stimuli, a hand was shown grasping a cup in the absence of context and an objectless background. Two types of grasping actions were used: either precision grasping (hand grasping the cup handle) or whole-hand grasping (hand grasping the cup body). The Context stimuli showed three dimensional objects such as a teapot, a mug or a cookie just before or just after having tea to elicit a drinking or cleaning context. For the Intention stimuli, the subjects were presented with both grasping actions in both drinking and cleaning context. When presented with the Intention stimuli, there is a significant signal increase in the premotor cortex; the posterior part of the inferior frontal gyrus and the adjacent sector of the ventral premotor cortex where hand actions are represented. The authors argue that the premotor mirror neuron areas are involved in understanding the intention of others, evident from a spike of signal in the FMRI when humans were exposed to Intention stimuli in the experiment.

Other experiments have shown that in pigtailed macaques, Macaca nemestrina, mirror neurons are also found in the inferior frontal gyrus (the F5 region). This region responded when the macaques make an active movements and also when they observe an experimenter making meaningful movements. (di Pellegrino et al., 1992; Gallese et al., 1996; Rizzolatti & Craighero, 2004; Hickok, 2009).

In a study by Platek et al. (2005), the authors found that the posterior cingulate and precuneus were activated during contagious yawning. These two regions are associated with the theory of mind and empathy. In another study from the same year, Schürmann et al. (2005) found that the superior temporal sulcus was the area that gets activated during contagious yawning. The superior temporal sulcus region is involved in the perception of eye gaze of others and are crucial in determining where others’ emotion are being directed through eye gaze (Campbell et al., 1990). Thus, neuroimaging results from Platek et al. (2005) and Schürmann et al. (2005) contradict each other in isolating the region of the brain that is activated during contagious yawning.

Two studies on contagious yawning from human to domestic dogs were published by Joly-Mascheroni et al. (2008) and Harr et al. (2008) in the same year. Joly-Mascheroni et al. (2008) were the first to demonstrate that human yawns are contagious to domestic dogs and that human yawns would elicit a yawning response from a non-primate species (domestic dog). In this ingenious experiment, Joly-Mascheroni et al. (2008) had 29 domestic dogs observed human yawning and making control mouth movements (not yawns). Out of the 29 domestic dogs, 21 of them yawned after observing a human yawning but none when exposed to control mouth movements (the control in the study). The experiment yielded impressive result, where 72% of the domestic dogs yawned when exposed to a human yawning. This is a higher rate than contagious yawning between humans (45% – 60%) (Provine, 1986; Platek et al., 2003) and from human to chimpanzee (33%) (Anderson et al., 2004). Joly-Mascheroni et al. (2008) posit from this experiment that domestic dogs possess a rudimentary empathic capability and that it helps in moderating human-dog interaction and communication.

A later study by Harr et al. (2008) in the same year also investigated whether human yawns are contagious to domestic dogs but used a different method than that of Joly-Mascheroni et al. (2008). Harr et al. (2008) used 15 domestic dogs in their experiment; the domestic dogs were shown video clips of humans and domestic dogs displaying yawns and open mouth expressions (not yawns) to determine whether these two social stimuli would elicit yawning in these domestic dogs. Their results show that the domestic dogs yawned on both stimuli (yawn and open mouth expressions) with no significant difference as determined by paired t test. Citing methodological difference than that of Joly-Mascheroni et al. (2008), Harr et al. (2008) posit that their results were due to using video clips instead of using live human models. They also conclude that it is possible that domestic dogs, like humans, attended differently to video stimuli than that of a live model.

Järveläinen et al. (2001) showed that in humans, there is a stronger reactivity time in the mirror neuron system when viewing live motor act than that of an artificially presented act. It is possible that domestic dogs also pay less attention to an artificially presented act than that of a live motor act. Understanding the umwelt of domestic dogs is important when using them as experimental subjects and to answer species-specific questions. Domestic dogs are excellent at reading human communicative and visual cues (Joly-Mascheroni et al., 2008) but maybe only so on live model and not video clips as evident from Harr et al. (2008) experiment. Thus, experiment on contagious yawning from human to domestic dogs should considering using only live models and not video clips.

P/S - Sorry if I made you yawn ;)


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