Elephant See, Elephant Do: Evidence of Social Learning in Elephants

By Sophie Wasserman

In 2010, a group of researchers working with African elephants combined their almost 30 years of behavioral data to try to understand the phenomenon of “false estrous.” Females who weren’t in estrous (were not sexually receptive and able to conceive) were demonstrating all the typical signs of being in heat: holding their head and tail high, exaggerating their walk, and touching males more frequently. What the scientists found was that in each case of “false estrous,” the faker was in close proximity to a juvenile female entering estrous for the first time. Ruling out alternative explanations, the study postulated that these were teaching moments, that the naïve young females were being shown the correct behavior and learning from the older females’ demonstrations. 

Elephants are reared in tight knit family groups
via Wikimedia Commons

 Instances like these are called social learning, when an individual takes information gained by observing the behavior of others and applies it later to similar situations. In other words: monkey see, monkey do. Though it sounds simple, social learning is actually a complex cognitive process and is thought to indicate high intelligence in a species. 

Herd of Asian elephants

via Wikimedia Commons

            Typically, mammals are already born with about 90% of their adult brain weight, such that most of their behaviors are innate and instinctual. Humans, on the other hand, are only born with about 28% of our adult brains, so much of our knowledge and behavior has to be acquired during our childhood as our brain develops. Estimates for the natal brain weight of elephants range from 35-50%, indicating they too have a lot of learning to do as they grow up.

The most prevalent examples of social learning in elephants are found in young calves during their periods of high brain development. To learn proper foraging techniques, calves will examine, and sometimes “steal,” the food in their older relatives’ mouths, sampling the foods that are safe to eat to learn their taste and smell. Calves as young as 18 months have been shown to mimic the fly switching behavior of older adults, grasping and modifying a branch to use as a tool to repel insects after having seen their mothers do the same. Young males will follow full-grown bulls, observing their interactions with estrous females and smelling all of the same puddles of urine to refine their sense of smell.

Calf samples mother's snack
via Wikimedia Commons

An attempt to empirically demonstrate social learning in elephants produced mixed results. Researchers at the San Diego Zoo constructed a variety of puzzles that could be solved one of two ways, both of which resulted in a tasty treat for the elephant. In test conditions, each puzzle was first given to the matriarch of the herd, while another female was placed in an enclosure alongside. After the second female was given time to observe the matriarch, the matriarch was removed and the second female was allowed access to the toy. 

Bleum scratches herself with a stick as Am looks on

Contrary to predictions, the second elephant was just as likely to copy the puzzle solving strategy of the matriarch as to adopt the second unobserved strategy for solving the puzzle. However, the second elephant spent much more time examining and playing with the apparatus when she had witnessed the matriarch doing so, as compared to control conditions when the female was given access to the toy with no prior social exposure. In this way, the elephants are showing non-imitative social learning; the observer elephant is not directly learning a sequence of movements, but rather learning the value of a particular object, in this case, that the toy provides food.

The importance of social role models in elephant society is also demonstrated by the abnormal behaviors of elephants when they lack one. Wild elephants were played recorded elephant calls from a variety of individuals classified as non-threatening (those who were familiar or young and less dominant) or threatening (unfamiliar or older and more dominant). Herds in Amboseli National Park, which has remained relatively untouched by humans, were better able to recognize threatening calls, reacted with more listening and sniffing, and bunched together more frequently than the herd in Pilanesberg Park, which had been translocated as calves after the controlled culling of all the older elephants. The Pilanesberg elephants who were raised without role models did not show appropriate defensive measures when exposed to the more dominant calls, something the Amboseli elephants had passed down from older to younger generations

Mother and calf
via Wikimedia Commons

These findings have important ramifications for current human-elephant conflict. Though the practice of culling is dying out, the upswing in poaching has similar effects; by removing large, dominant individuals, poachers are destroying the fabric of elephant society, leaving behind calves to grow up with no guidance. With no social role models, young males especially can become out of control, exacerbating tensions between local human populations and their dwindling elephant neighbors. Further research into social learning, examining how and when elephants learn from each other, could shed some light on possible solutions to this troubling problem. 

References

Bates, L. A., Handford, R., Lee, P. C., Njiraini, N., Poole, J. H., Sayialel, K., ... & Byrne, R. W. (2010). Why do African elephants (Loxodonta africana) simulate oestrus? An analysis of longitudinal data. PloS one, 5(4), e10052.

Greco, B. J., Brown, T. K., Andrews, J. R., Swaisgood, R. R., & Caine, N. G. (2013). Social learning in captive African elephants (Loxodonta africana africana). Animal cognition, 1-11.

Shannon, G., Slotow, R., Durant, S. M., Sayialel, K. N., Poole, J., Moss, C., & McComb, K. (2013). Effects of social disruption in elephants persist decades after culling. Frontiers in zoology, 10(1), 62.

http://www.elephantvoices.org/elephant-sense-a-sociality/elephants-learn-from-others.html

Images

Elephant family by Siddharth Maheshwari via Wikimedia Commons

Herd of Asian elephants via Wikimedia Commons

I will follow you by Lip Kee via Wikimedia Commons

Mother and elephant calf at Lampang conservation center by Dpservis via Wikimedia Commons

Existential Elephants: Common Illnesses

by Lisa Barrett

It is widely known that elephants can live to be very old (sometimes up to 65 or 70 years!)--just like humans—but what causes an elephant to finally kick the bucket? And how has our knowledge of these health issues in elephants helped to extend their lifespan in captivity? Please excuse the morbidity, and let’s talk causes of elephant death.

Unfortunately, humans are to blame for most causes of elephant death, including habitat loss, fragmentation, and poaching for ivory and meat. But don’t feel too guilty, because you can have a meaningful impact on elephant conservation by educating your friends and supporting our cause (Donate here: http://bit.ly/J4l3gn). Since we have discussed these conservation threats in detail in previous blogs (feel free to scroll through to read about them!), I will focus on a few other causes of elephant death. 

Most elephant deaths are caused by humans (through poaching or habitat destruction).

Photo from: http://

bit.ly/1iViAoO 

There are a number of illnesses that target different populations of elephants. For example, we find foot problems (ex: zoo-genic foot disease, pressure cracks, and overgrown nails) to be much more common in captive elephants than in their wild counterparts. This is especially true of zoo elephants, who historically were made to stand on hard concrete floors. Fortunately, this issue is being mitigated as zoo enclosures become better-designed for elephants. Another painful foot issue affects street elephants who walk on paved roads or concrete for extended periods of time and may develop smoothed feet and lose necessary traction.

Elephants in captivity may suffer from serious foot problems. 

Photo from: 

http://bit.ly/JdiwkF

Elephants in the wild may succumb to more naturally occurring diseases. For example, anthrax, which is transmitted by rats, can lead to paralysis of the trunk. Heart disease, twisted gut, and parasite infections are other major illnesses contracted by wild elephants. Interestingly, elephants in the wild have been known to seek out their own remedies to deal with illness. For example, digestive dilemmas can be treated by fasting or consuming bitter herbs or bark. They may also protect open wounds by coating them with mud! Our veterinary staff has employed several natural remedies to help cure elephant abscesses, like using paste from plant material known to aid in skin health.

Elephant herpes virus affects both wild and captive elephants. Interestingly, it greatly affects young Asian elephants, whereas African elephants generally experience benign versions of the virus. It causes fatal hemorrhagic disease and is believed to be transmitted between elephants through trunk secretions. What’s more, it can produce pinkish nodules on the head or trunk of juveniles. More research is critical to understand the causes and effects of this rather widespread disease among elephants, especially because there is no known cure to the elephant herpes virus.  

A nodular growth an an African elephant's trunk caused by elephant herpes virus.

Photo from:http://

bit.ly/IEB4tr

Tuberculosis is another common illness found in elephants, but it can also be passed between humans and elephants (and vice versa) through prolonged intensive contact. It is caused by mycobacterium tuberculosis in droplets in the air and affects the lungs and causes chronic weight loss, coughing, and diminished appetite.

Elderly eles who live into their sixties will most likely expire when their final (sixth) set of molars wear down and they are no longer able to chew or ingest their food, which will lead to starvation. Some captive elephants living out their lives receive special diets of mashed bananas to help mitigate this.

In order to avoid late detection of any illness at the elephant camp, the elephants here at the Golden Triangle Asian Elephant Foundation receive regular health check-ups from our elephant veterinarian, Dr. Cherry. She uses positive reinforcement to have her patients present certain body parts for examination. 

Here, Dr. Cherry checks the feet of an elephant.

Photo from: Lisa Barrett

Resources:

http://www.elephant.se/elephant_diseases.php?open=Elephant%20diseases

http://www.elephant.se/elephant_herpes_virus.php

http://www.seaworld.org/animal-info/info-books/elephants/longevity.htm

  

Journey Through the Center of an Elephant

As anyone who's spent even a few hours with an elephant will tell you, elephants spend most of their time (in fact, 12 to 18 hours every day) doing just one thing: eating.  From sugarcane to bananas, grass to ferns, Asian elephants eat over a hundred species of plants.  In order to support such a large body mass on plant matter alone, elephants need to eat up to 250 kilograms of food every day.  Although this number makes sense when considering their massive size, it is still a fairly high volume of food to need on a daily basis.  Why do elephants need such an impressive amount of food?  Well, elephants are actually not particularly good at digesting what they eat.  In order to process the nutrients from this endless stream of vegetative snacking, elephants have developed a massive, and massively inefficient, digestive system.

Photo by Rebecca Shoer

First, and most importantly, elephants are not what scientists refer to as "ruminants:" animals that digest their food by processing it through a combination of regurgitation (chewing cud) and passing the food through multiple stomach compartments.  This process is quite good at extracting nutrients from ingested vegetation.  Ruminants also depend on maintaining a steady population of bacteria in their stomachs, which break down the plant matter in such a way that the host animals can absorb the nutrients.  Elephants, along with all other "non-ruminant" herbivores, do not possess multiple stomach compartments, or chew their cud.  They do, however, utilize symbiotic bacteria to break down their food.

So what method do elephants use to extract nutrients from their food, other than hosting some friendly digestive bacteria?  Well, as you can imagine, elephants have a tremendously long digestive tract.   Food is first ground into oblivion by four massive molars, the only teeth that elephants possess (though they will have six sets of molars in a lifetime).  It is then passed through the esophagus to the stomach.  The stomach of an elephant is quite different from a human stomach--rather than being the primary site of digestion, it is mainly a large food-storage area.  The stomach is roughly cylindrical, and can store between 30 and 70 litres of food in a full-grown adult! 

The food is then passed along into the small intestine, or duodenum, which can grow to a spectacular 19 meters in length.  The food travels along to the spot where the small and large intestine meet, in an area called the caecum.  It is here that most digestion takes place, because a healthy population of bacteria break down the cellulose in plant matter to make it nutritionally available to the elephants (of course, the bacteria get to snack as well).  This process releases gases as a digestive side effect, and this is why elephants can let loose with some pretty spectacular flatulence.  Seriously, it's pretty amazing:

http://picosong.com/kRjr/

Sound provided by Buathong (via Lisa Barrett)

As food travels along the caecum, nutrients are absorbed into the bloodstream through its fairly thin walls.  After this, food travels through the large intestine, or jejunum, until all of the moisture is sucked out.  Finally, the food ends up as a nice pile of uniform dung.

Dung with accompanying mushrooms

Now, you might think that this lengthy process (almost 14 hours) would result in dung that has just about every nutritional particle sucked out of it.  In fact, just about the opposite is true.  Elephants digest barely one half of the nutritional value of their food, which means that their dung is nutrient rich.  This inefficiency in digestion is one of the reasons that elephants are an integral part of their ecosystem.  Just about anybody who's anybody uses this dung: baby elephants eat it, frogs live under it, mushrooms grow from it, and some plant species will only sprout once their seeds have been processed and deposited in elephant dung!  Elephants are an amazing and essential seed disperser, ensuring that trees and plant species are evenly and widely distributed throughout their habitat.  One survey of elephant dispersion refers to elephants as "megagardeners," so important are they to the ecosystem.

Of course, elephants are most likely not consciously deciding where to disperse their dung based on ecological needs.  Still, their importance, and the importance of their digestion, cannot be overstated.  Without elephants, these ecosystems will change in unknowable ways, possibly collapsing, and quite definitely threatening the survival of countless species that depend on this dung.  For elephants and their neighbors, an inefficient system has proven to be a very good thing.

References

Campos-Arceiz, A. and Blake, S. 2011. Megagardeners of the forest- the role of elephants in seed dispersal. Acta Oecologica. 37:542-553.

Digestive System http://elephant.elehost.com/About_Elephants/Anatomy/Internal_Systems/The_Digestive_System/the_digestive_system.html

Elephant Digestive System http://www.elephantsforever.co.za/elephant-anatomy.html

Elephant Anatomy and Biology http://www.asianelephantresearch.com/about-elephant-anatomy-and-biology-p3.php