Hi there!  I'm Rebecca, one of the new research assistants here at TEI.  I'm from central Massachusetts, so this has certainly been a big change in climate/geography/language from home.  After a month in the Golden Triangle, I think I'm finally settling into life in a Thai village (of course, I don't think I'll ever get used to elephants!).  One of the things I find most interesting about elephants is the relationship between them and humans, and the ways that we have affected each other.   

Elephants have worked with humans for thousands of years--in Thailand, elephants are inexorably tied to every aspect of the culture.  Elephants were used in war, as a symbol of royalty, in the logging industry, and, more recently, in tourism.  However, are these animals what we would consider "domesticated?"  In order to answer that question, we need to look at the history and the science of the domestication process.

Domestication, in the most technical sense, is the process of artificial selection.  This means that humans, versus evolutionary pressures, artificially choose what traits should be passed on in an animal population.  In dogs, for example, humans looked for friendliness, loyalty, and, in some breeds, a specific hunting ability.  Corgis were bred to herd livestock, and thus even corgis that have never worked on a farm will instinctually try to "herd" other animals (or even children!).  Dogs have thus evolved alongside humans, and have developed significant abilities in understanding human behavior.  Most interestingly, dogs can recognize the meaning of a human pointing to an object--they can even follow a person's gaze to locate a hidden object.  Wolves, on the other hand, do not understand these types of gestures.  Even wolves raised in captivity do not have this ability.

Cardigan Welsh Corgi and Canis lupus photos via Wikimedia Commons

In addition, domesticated dogs are physically different from their wild predecessors.  Many of these differences were chosen artificially for aesthetic reasons, but some changes in physical appearance may simply be part of the domestication process.  During the 1960s a study was started in the (then) Soviet Union on the domestication of wild foxes (Trut, 1999).  Researchers selected fox pups based solely on temperament; the most friendly pups were chosen to breed and have pups of their own.  In only a few generations, the scientists were reliably producing foxes that were friendly and playful with humans.  However, they also discovered that the foxes were physically different from their wild cousins: the adult domesticated foxes had floppy ears, curled tails, and some developed piebald coats.  None of these traits are expressed in adult wild foxes; they are, however, found in pups.  Domestication causes neotony, a process through which adults retain juvenile physical traits.  This is why dogs look more like wolf puppies, rather than adults. 

Finally, domestication also changes animal brains.  The brains of domesticated animals are smaller than their wild counterparts, possibly because it results in a reduction of aggression (McAuliffe, 2011).  In addition, gene expression levels in the brain differ between domesticated and wild species (Albert et al., 2012).  It seems logical that dramatic behavioral changes would accompany cerebral changes.

But what about elephants?  Although elephants raised in captivity can be friendly and even affectionate with the humans they work with, they are not domesticated.  They have not changed in appearance due to generations of human contact, and are behaviorally no different at birth when born to captive versus wild mothers.  If a calf were born to a captive mother but raised in the wild, that calf would become a wild adult.  On the other hand, a dog raised in the wild will still retain domesticated characteristics.  This is exciting for our research--we are able to test the intelligence of a group of wild animals in a controlled and relatively safe setting.  And most importantly, we can use our research and elephants here in the Golden Triangle to help wild elephants throughout the rest of Asia. 

 References

Albert FW, Somel M, Carneiro M, Aximu-Petri A, Halbwax M, et al. (2012) A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals. PLoS Genet 8(9): e1002962.

Canis lupus lupus By Quartl (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Cardigan Welsh Corgi By Kubek15 (own work on my camera) [Public domain], via Wikimedia Commons

McAuliffe, Kathleen. "If Modern Humans Are So Smart, Why Are Our Brains Shrinking?" Discover.  January 20, 2011.

Trut, Lyudmila (1999). "Early Canid Domestication: The Farm-Fox Experiment". American Scientist 87 (2): 160. 

Learning to Think Elephants

Hi! I'm Sophie, one of the newest additions to the Think Elephants team. After completing my first month of intensive training in the Golden Triangle, I’m almost positive that a) I can rattle off more elephant facts than I ever thought possible, b) most of my new tan is actually just a thin layer of persistent mud, and c) I stumbled upon the perfect post-graduate position. The first is a necessity of the job, the second a byproduct of the rainy season and thorough investigations by curious trunks, and the last both a relief and a joy to discover. I’m exhausted at the end of every day, but it is the satisfied type of fatigue that has me looking forward to doing it all over again tomorrow.

Besides getting a good night’s sleep, success as a research assistant with Think Elephants International requires effective communication. Our days are filled with educating visitors from of all ages and backgrounds, discussing projects and results with team members, and trying to convey wishes to mahouts whose English is somewhat--but not quite sufficiently--better than my Thai. Most importantly, though, you need to be able to communicate with the elephants

More than just learning a few verbal commands, as a researcher you need to know what your subject understands about the presented problem. If the elephant doesn’t gather and grasp all of the information relevant to the experiment, how can it ever be expected to find the solution? Previous posts on this blog have explored the limitations of an elephant’s visual system (Seeing Red), and the most recent paper published by Dr. Josh Plotnik and his team of middle school collaborators demonstrated that elephants do not use visual cues to find a food reward. This has been one of my favorite aspects of the job so far: adapting experimental paradigms designed for species that favor visual input, such as humans and apes, to suit animals who rely heavily on olfactory and tactile information gathered by their trunk. It’s a challenging but fascinating brainteaser that requires a lot of creativity, flexibility, and patience. In a perfect catch-22, if you can’t learn to think like an elephant then you’ll never fully understand how elephants think.

The ability to “think elephants” is a new skill I’m trying my best to acquire quickly; there was, in fact, a distinct lack of pachyderms included in my liberal arts experience. I graduated in May from Haverford College, where I spent four years working towards a BS in Psychology, with a concentration in Neural and Behavioral Sciences. The major focus of my studies was Cognitive Neuroscience, looking at the underlying mechanisms of ideas, memories and emotions in the human brain. I spent a summer analyzing data from a longitudinal study of children with early brain damage, looking specifically at deficits in their language development and the degree to which their neural circuitry could adapt and compensate. For my senior thesis work, I switched to the opposite end of the age spectrum, examining the changes in emotion regulation and attentional control of older adult populations as measured through a harmless electrode cap.

I enjoyed conducting research, but a windowless room, full of the endless peaks and troughs of recorded brain waves, finally convinced me I wasn’t ready to commit to life in a lab just yet. Coupled with the fact that my favorite classes in college were on primate social structure and the neuroscience behind animal behavior, I started looking for internships in zoos and aquariums. I would love to say that something more exciting than a methodical search of job postings on the internet brought me to TEI, but the months of virtual legwork were an important part of solidifying which directions I did (and did not) want to take in my fledgling career. Though I’m still not sure where I’ll end up after my time with TEI, I’m looking forward to the next year of delicious food, passionate co-workers, and elephants with personalities larger than their already massive body size.

Elephants Never Forget

People often ask, ‘do elephants really never forget?’ Quite simply, yes an elephant never forgets. Elephants are extremely intelligent, social, long-lived and large brained animals. They possess remarkable memories of migration routes, water and feeding spots and they can remember the scents and vocalizations of many different individuals (both elephant and human). Thus, this is not just another elephant ‘myth’. This blog will look into the body of evidence surrounding this saying.

The elephant brain

Elephants have the largest brains among all land mammals, averaging 5 kg in weight. In theory, the larger the brain, the more cognitively complex it is. While we cannot judge brain efficiency on size alone, it can give us an indication of the power of elephant memory. One method of measuring intelligence and brain power among animals is to look at the ‘Encephalization Quotient’ (EQ). EQ compares the actual size of brain mass to the expected brain mass of a typical animal of that size (Jerison, 1973). Elephants have an average score of 1.88 (Shoshani et al, 2006), whereas chimpanzees have an EQ of 2.5 and humans 7.

Elephants have complex brain structures. They have the greatest volume of cerebral cortex available for cognitive processing of all land mammals. This enables them to have greater capabilities for learning and knowledge retention. Elephants also have a large neocortex, which is the part of the brain that is used for a working memory, planning and spatial orientation.

                                                                  Public Domain Clip Art

Memory of water and feeding sites

African elephants are known to travel vast distances in search of food and water. They can remember many different water sites which are thousands of kilometers apart. For example, in Namibia and Mali, the elephants have extremely large home ranges of up to 11,000 square kilometers. These large home ranges are due to the sparse distribution of water sources, which can be over 60 km apart. These elephants must remember the location of all these water sources in order to survive, even when some are only used once a year. This example indicates that elephants have exceptional cognitive mapping skills.

The elephants of the deserts of northern and southern Africa also provide another impressive example of the ecological memory of elephants.  They have been found to travel hundred of kilometers in order to reach remote water sources shortly after a period of rain. Sometimes they use routes which have not been used for many years, highlighting the incredible mental mapping memory of the matriarch (oldest and most knowledgeable elephant who leads the herd), which is dependent upon long-term memory of these matriarchs who have travelled on these routes previously, or who have been passed down this knowledge (McComb et al, 2001).

Memory of people

Elephants also have a great memory of people.  One study in the Amboseli, found that African elephants react negatively to the scent and sight of clothing belonging to the Maasai tribe. In Kenya, young Masaai men demonstrate their manhood by spearing elephants. Thus, the elephants are able to remember and associate the smell of the Massai with spearing, which is a threat to them (Bates et al, 2007).

My good friend and vet at GTAEF, Dr Cherry, always amuses me with her stories about her relationships with the elephants. One story which comes to mind, and highlights that elephants really never forget, is that of a little 6 year old elephant called Pumpui. A few years ago, Dr Cherry had to treat a hip abscess that Pumpui had. The treatment was probably quite memorable as, for a long time after the treatment, Pumpui would not let Dr Cherry approach her, maybe from fear of having the treatment again. Pumpui has now got over this event and she now lets Dr Cherry approach her. This sort of story is not uncommon for elephant vets, as it seems the memory of injections and other treatments is quite vivid for elephants!

As for me, after having worked here for over a year, there are elephants that seem to remember me. For example, whenever I see one elephant called Poonlarb, she will immediately open her mouth and expect food from me. She will just stand there with her mouth open, waiting. If I don’t have food, I will just rub her tongue, which she likes too! I think she formed this mouth opening habit and association with me through food because she remembers me from research. At research, we use Poonlarb frequently, and elephants that come to research always get lots of tasty food rewards for completing different tasks. I definitely see the forming of such elephant relationships as a perk of being a researcher!

                                                               Poonlarb and I              

Memory of other elephants

Elephants recognize each other even better than humans! It is believed that elephants are able to keep a mental record of many different individuals. Elephants use contact calls to stay in contact with each other. One study in Africa found that female elephants are able to remember and distinguish between the contact calls of closely related females (family and extended family) and non-related individuals outside the extended family. They can remember contact calls from around 14 different families in the population, which is approximately 100 adult females (McComb et al, 2000). Elephants are also able to keep track of individuals by their incredible sense of smell. They can identify at least 17 individuals by the scent of their urine. This is a useful technique for keeping track of the positions of individual family members (Bates, et al, 2008).

There are countless stories of elephants (related and non-related) who have been separated from each other, and then years later being reunited and remembering each other. For example, at ‘The Elephant Sanctuary’ in Tennessee, when two elephants were reunited, they displayed very enthusiastic greetings towards each other. One of the elephants called Shirley, also displayed unusual mothering behaviors towards the other elephant, called Jenny. Later on, it was discovered that these two elephants, Jenny and Shirley, had previously known each other. They were kept together in a circus while Jenny was only a calf and Shirley was 30 years old. They were then separated and reunited and were able to still remember each other 23 years later!

Memory of deceased elephants

Elephants have also been seen to display a variety of different reactions towards the bodies of dead elephants or elephant remains. It has been reported that elephants investigate elephant bones or tusks that they encounter. It has also been suggested that they visit the bones of dead relatives, suggesting a long term memory of individuals that had previously died.

Elephants really are quite remarkable animals. They really do ‘never forget’, which is quite a rare trait in the animal kingdom and suggests that elephants are not too dissimilar from ourselves. 

References

• Bates, L.A., Sayialel, C.N, Njiraini, N.W, Poole, J.H., Moss, C.J. & Byrne, R.W. 2008. African elephants have expectations about locations of out-of-sight family members. Biology Letters: 4, 34-36.
• Bates, L.A., Sayialel, C.N, Njiraini, N.W, Poole, J.H., Moss, C.J. & Byrne, R.W. 2007. Elephants classify human ethnic groups by odour and garment colour. Current Biology. 17, 1-5
• Jerison, H.J. 1973. Evolution of the Brain and Intelligence. New York: Academic Press.
• McComb, K., C. Moss, S. Durant, S. Sayialel, L. Baker. 2001. Matriarchs as repositories of social knowledge. Science 292: 491-494.
• McComb, K., C. Moss, S. Sayialel, L. Baker. 2000. Unusually extensive networks of vocal recognition in African elephants. Anim. Behav. 59:1103-9
• Shoshani, J., Kupsky, W.J. & Marchant, G.H. 2006. Elephant brain. Part I: gross morphology, functions, comparative anatomy, and evolution. Brain Research Bulletin 70: 124-157

Elephant's Phylogeny

Ever wondered who the elephant's closest relatives are ? How big the ancestors of the elephants were? What they looked like? Take a tour of our interactive phylogenetic tree and start a journey into the past of our gentle giants. To navigate the tree, click on "start prezi" and then the following icon to go fullscreen!

To zoom in and out, move your mouse. The following icons should appear: click on the magnifying glasses to zoom and unzoom. Alternatively, use the up and down arrows on your keyboard. (Hint: follow the "magnifying glass" icons... there are messages to explore!) The "house" icon brings you back to the original display.

If you want to look at a picture or a text more closely, just click on it. Enjoy!


Sources: http://www.pnas.org/content/107/10/4635/F1.large.jpg I, Killer18 [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-SA-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons http://en.wikipedia.org/wiki/Epitheria http://animaldiversity.ummz.umich.edu/accounts/Metatheria/ http://animaldiversity.ummz.umich.edu/accounts/Prototheria/ http://animaldiversity.ummz.umich.edu/site/accounts/information/Xenarthra.html http://www.mammalsrus.com/eutheria/hyracoidea/hyracoidea.html http://thaifossil.tarad.com/product.detail_134361_th_775890?lang=en# http://www.ucmp.berkeley.edu/mammal/mesaxonia/proboscidea.php http://www.youtube.com/watch?v=mgSNra4iUiE http://www.elephantexpert.com/2011/07/page-3.html http://nature.ca/notebooks/english/afeleph_p0.htm http://www.ucmp.berkeley.edu/mammal/mesaxonia/probos_distrib.gif http://www.sciencedirect.com/science/article/pii/S0169534798014918 http://en.wikipedia.org/wiki/Moeritherium http://ldaustinart.blogspot.com/2010/12/deinotherium.html http://www.nysm.nysed.gov/exhibits/longterm/mastodon/ By Creator:Dmitry Bogdanov (dmitrchel@mail.ru) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons By GYassineMrabetTalk✉ This vector image was created with Inkscape. (Own work) [CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Fight or... Flehmen

The flehmen response—unlike the adrenaline induced responses for fight or flight—provides a wide range of animals with a means of receiving chemical information about their social world. Animals, including elephants, use the flehmen response predominantly to access information from other individuals related to their corresponding reproductive status. The response typically involves investigation of a urine sample from another individual or investigation of another individual’s genitals directly. Alternatively, animals may exhibit the flehmen response to analyze foreign or novel odors.

Flehmen responses usually operate through a curling back of the upper lip and subsequent inhalation of a scent. The scent is inhaled orally, bypassing the primary smell system reliant upon the nostril passages and instead directed toward the vomeronasal organ (VNO) located above the roof of the mouth and accessible via a duct (pictured below).

Duct leading to the VNO (aka Jacobson’s organ) within the roof of the elephant’s mouth

 In animals such as the Boer goat the curled back upper lip actually appears to physically obstruct the nostrils (Author: Böhringer Friedrich).

As with pretty much every other communicatory function, the superstar appendage that is the trunk plays a prominent role in the elephant’s flehmen response. The elephant will contact a substance with the protuberance on the tip of the trunk referred to as a finger. The substance is then transported by the trunk to the VNO at the roof of the mouth.

Try to imagine grabbing an object with your nose and you realize pretty quickly how starkly different we are from elephants. The elephant’s sense of touch and sense of smell are inextricably linked. Evolution had different plans for us, providing us with not one but two front limbs which—no longer required to assist us in locomotion—have been freed up for object manipulation. (Perhaps, the icing on the cake for us humans is that evolution managed to keep our nosy smell organ from becoming entangled within our highly adapted hands… although, the elephant would probably highlight this point as a rather distinct disadvantage.)

Bestowed by our ancestors with incredibly deft manipulation tools (hands), imagine how easy it’d be for us to perform the flehmen response on a sample of urine. I suspect we’d follow the elephant’s lead of directly transferring odorants instead of taking deep inhalations. Of course… we’d need a vomeronasal organ of our own to finish the job. Otherwise any chemical information from the urine would fall upon the vomeronasal equivalent of pinched nostrils.

As someone who’s never consciously received chemical information from urine, and who’s definitely never actively transferred urine by hand to the roof of his mouth, you can imagine my surprise when, while researching the VNO further, I discovered that I myself might very well possess my own VNO.

While many issues surrounding the human VNO are highly debatable, the existence of a VNO in human embryos is not one of them. Even in some adults, the same location (near the nasal septum) is occupied by a structure similar to the VNO found in human embryos. Reports vary widely on this second point. Still, as Michael Meredith notes emphatically in his critical review of the evidence surrounding the human VNO, structural evidence for the organ in no ways implies that the organ is functional.

The way I see it—emphasis on see—unlike elephants who rely more heavily on smell than sight, the primate tree has grown in a direction that favors visual signaling pathways in place of chemical ones. This sensory preference has left us with a vestigial VNO, a remnant of our ancient ancestors. Is it an old structure? Sure. But when considering its function or value, it’s likely to be about as wise as our wisdom teeth. And by that, I mean not very wise at all. Those are some poorly named teeth.

Reference

Meredith M (2001). Human Vomeronasal Organ Function: A Critical Review of Best and Worst Cases. Chem. Senses 26:433-445.