Thursday, January 30, 2014

Ligers and zonkeys and eles oh my!

If the Internet has taught us anything, it's that we love strange and adorable animals.  Possibility one of the most reliable sources of such creatures is hybrids: we love discovering new, and sometimes fictional, animal creations.  Although when we hear the term "hybrid," we often picture a car, it is used in biology to refer to an organism that resulted from cross-breeding of (typically) two different species.  Hybrids are quite common in plants, though today we are going to focus on animal hybrids (our apologies to our botany fans).  There are many well-known types of hybrids in the animal kingdom, including the liger (a lion/tiger), mule (a horse/donkey), and zonkey (zebra/donkey).  For most hybrids, the physical appearance and name of the animal depends on the sex of each parent species: the difference between a tiglon and a liger depends on species of the mother and father. For example, a liger is a cross between a male lion and a female tiger, while a tiglon is a cross between a female lion and a male tiger. 

hercules liger
Hercules the liger

Many hybrids occur in nature, especially amongst plants.  Some, however, only occur when two species are artificially housed together in captivity.  Even when housed together, though, some animals simply can't breed to form hybrids (even if they seem closely related).  The resulting fetus may not be carried to term or, even if it is, it may be nonviable.  This means the hybrid itself cannot breed--this is the case with mules.  The only way to get new mules is by crossbreeding horses and donkeys.

Hybrids between two species in captivity are quite often unexpected.  For example, Ippo the zonkey was born this year after his  father (an amorous zebra) jumped the fence into an enclosure holding a female Amiata donkey.  The owners were quite surprised when, a year later, their donkey gave birth to a striped foal!

Ippo the zonkey foal

For such a hybrid to occur between two historically geographically separated species is quite incredible.  In the case of elephants, it was long believed that African and Asian elephants would be unable to produce a hybrid that could be carried to term and born successfully.  Asian and African elephants have been separate species for almost 7 million years; Asian elephants are actually more closely related to the now-extinct wooly mammoth than to African elephants.  Thus, African and Asian elephants have been kept in the same enclosures in some zoos and parks, with little concern for any inter-breeding that may occur.  Even if a male elephant were to mate with a female, it was not believed that any offspring would result.

However, in 1978, keepers at the Chester Zoo in the UK were shocked to discover that Sheba, their female Asian elephant, was pregnant.  The only possible paternal candidate was Jumbolina (also called Bubbles), a male African elephant.  Much to the keepers' amazement, Sheba carried her calf succesfully, and gave birth on November 7, 1978.  He was named Motty, after George Mottershead, the founder of the Chester Zoo who had recently passed away.

Motty with his mother

Motty was undersized and unable to stand soon after his birth, which suggested that he was born prematurely.  However, he appeared to do well after hourly feedings of glucose supplementing his mother's milk.  Amazingly, Motty sported a beautiful mix Asian and African physical features.  He had large ears, shaped like those of a typical African elephant.  His legs were long and slim like an African elephant, and he had a large single dome on his head.  However, he also had two smaller domes behind the large one, like an Asian elephant.  Motty had Asian elephant features in other ways: a single "finger" on the end of his trunk, and the typical five-four front-back foot toe nail pattern. 

Photograph demonstrating the mixed Asian and African elephant traits

Sadly, a week after his birth, Motty developed an umbilical cord infection, and rapidly fell ill.  Two days after starting treatment, Motty passed away from necrotic-enterocolitis and E. coli.  He was exactly two weeks old.

It's unclear why Motty got so sick so quickly--most likely, premature care for elephants at that time was not as effective as it is now.  Perhaps, if Motty had been born in 2014, he would have been successfully treated and survived.  Unfortunately, we will never know if he was viable and able to reproduce himself.

Although a sad story, Motty is a remarkable example of cross-breeding.  Although African and Asian elephants are not only different species, but also belong to different genera, they were able to interbreed.  Such a hybrid may never occur again, and there's no reason for it to, but it is certainly a remarkable example of nature defying our expectations.


Tuesday, January 21, 2014

How to Act in the Face of Biodiversity Loss: Conservation Behavior

By: Elise Gilchrist

Conservation behavior is a field of study that has both many proponents and many skeptics. This field uses animal behavior research to inform the design and application of solutions to halt the loss of biodiversity. Some scientists, however, have argued that the study of animal behavior does not make a useful contribution to conservation work. Fortunately for me, I had a professor in college who turned me toward some literature that argued for the great potential that this research has on wildlife conservation. Luckier still, I now work for an organization that puts this idea into action before my own eyes.

            One paper I found particularly useful when researching this topic offers a conceptual framework for how animal behavior can be integrated into the work of conservation biologists. Berger-Tal et al. (2011) give an overview of three areas in which they believe animal behavior research is most applicable to conserving wildlife.

            The authors begin by discussing how human induced, or anthropogenic, changes have both direct and/or indirect impacts on animal behavior. Overfishing, fragmentation of the environment, and the introduction of alien species are all examples of ways in which humans can alter the behavior of wild animals. Such alterations to the environment can make it so that once-beneficial behaviors are no longer adaptive. If a behavior is plastic, or easily modified, there are long-term concerns about humans can alter an entire population’s behaviors. If behavior is not plastic, then the animal may no longer be well prepared to interact with its changed environment. If it is established that a species’ behavior is not very flexible, then it is a good indication to conservation biologists that any rapid changes to its surroundings may lead to population loss of the species.

            The authors advocate a second area in which animal behavior can play a key role in conservation called behavior-based management. In other words, anyone involved in decisions like reserve design, corridor planning, or location choice for reintroductions must have an understanding of their target species’ behavior. For example, translocation of a population of birds from an island greatly affected by human activity to a more pristine island seems like a great idea. However, if the original site contained no predators to these birds it seems obvious that they may not have strong predator avoidance behaviors. If they are translocated to a site that contains novel predators, it is likely that the move will not be a success. It is this type of situation where animal behavior expertise can lend a helping hand to conservation efforts.

            Lastly, by observing changes in behavior, conservation biologists can look for early indications of declines in habitat health. In the same way, behavior can be used to monitor the effectiveness of management programs. An important way to monitor whether ecotourism is having negative effects on surrounding fauna is to watch for notable signs of stress in the target species. For example, some whale species come to the surface to breathe less often when whale-watching boats are in the vicinity. This has negative effects on the health of those whales and indicates high stress levels. Without the careful monitoring of behavior it might be difficult to assess the coming deterioration of environments or populations.

One fact that most proponents and critics of conservation behavior can agree on is that science, as a whole, needs to be more accessible to the general public, and in particular, those who have direct conservation impacts.  This means providing accessible research to individuals in roles that range from park rangers to policy makers to students. This is where Think Elephants International is showing a real proactive change. A foundation that is split in half between research and education sets itself up to disseminate knowledge gained through scientific study. Hopefully including students in our work will help influence a next generation of more conservation minded individuals. 

            If you are interested in learning more about applications of behavioral science on conservation work in New Zealand, I highly recommend reading:

Moore, J.A., B.D. Bell, and W.L. Linklater. 2008. The debate on behavior in conservation: New Zealand integrates theory with practice. BioScience. 58: 454-459


Berger-Tal, O. et al. 2011. Integrating animal behavior and conservation biology: a conceptual framework. Behavioral Ecology. 22: 236-239

Tuesday, January 14, 2014

Odd Ones Out: Questions That Didn't Follow the Herd

By Sophie Wasserman

As an organization dedicated to conservation education and public outreach, the Think Elephants International (TEI) team answers a lot of questions. In fact, the most common subjects we get asked about have inspired a large number of our previous blog topics. This week, however, I’ve decided to use this blog to answer the uncommon queries: those questions that stuck out most in our minds as truly interesting and unusual. So here, in no particular order, are the top 5 most unexpected questions from the past 6 months:

“Do elephants have birthdays?”

Boonsri has her birthday party hat on

            An overwhelming favorite here in the office, this question came from an inquisitive five year-old. Yes, elephants do have birthdays; Little Pumpui’s, for example, is September 1. As far as we know, they don’t celebrate them like humans would, but sometimes mahouts will give their elephants special treats like extra fruit. Interestingly, elephants don’t have a particular calving season and can give birth at any time of the year, but typically more births occur during the plentiful rainy season rather than the harsher dry season.

“Do they like it if you scratch behind their ears?”

Am enjoys a nice scratch
Photo by Lisa Barrett

            Keep in mind that an elephant is not a pet; they’re not bred to crave human affection like a domesticated dog (or, when it’s in a good mood, a cat). That being said, individual preferences vary from elephant to elephant. Some love a scratch under the chin, others like a nice back rub. Am will happily raise her leg to allow better access to her favorite spot and Bleum will open her mouth insistently until you give her tongue a massage. However, you should never hug an elephant around the trunk, because you could constrict their breathing, especially the younger calves.

“Can they speak English?”

Namchoke and her mahout Pom

            The elephants here in Thailand are primarily trained using a combination of words from Thai and a unique elephant language. So if I wanted one of the elephants to walk towards me, they wouldn’t respond to me shouting, “come here” in English. Could we teach them English commands? Sure, the elephants don’t “speak Thai,” they only recognize combinations of sounds. The elephants could learn to respond to Spanish or Swahili just as easily. Though most of the elephants understand over 80 different commands, there is currently no evidence that they grasp grammatical structure or complex syntax.
As for actually speaking English, except for one case of a zoo elephant in Korea mimicking the speech sounds of his keepers, there is little evidence that points towards the ability to produce a spoken language like English. Most elephant vocalization utilizes the trunk, which is not adapted to produce the same type and range of sounds that human mouths are.

“Can they smell fear?”

Boonjan scents her surroundings
            Now that’s a tricky one. The short answer is that we have no idea. The long answer is that when people say animals like dogs or horses can “smell your fear,” what they mean is that often these animals will recognize and react differently to a person who is clearly afraid. It is currently unknown whether these animals are seeing the social cues associated with fear, such as changes in voice, posture or facial expression, or actually “smelling” changes in the composition of our sweat. Recent research has shown that even humans might be subconsciously sensitive to the difference between fearful sweat produced when waiting to give an oral presentation and non-emotional sweat released during exercise, but the mechanism by which we might do that is still unclear.
         Turning back to elephants, our research has shown that they don’t seem to pick up on human cues such as pointing (Check out the paper here). This makes it less probable that elephants would be sensitive, like a domesticated animal, to our gestural communication of fear. However, since fear is a primal emotion that conveys a nearby threat, it could be to their evolutionary advantage to recognize fear in different species.  
As for actually smelling fear, elephants have a well-developed vomeronasal organ (Detailed in Dan's blog here), which allows them to detect chemical information about pheromones and hormone levels in the urine of other elephants. Though there is a possibility that it could also detect signs of stress and fear in the body odor of humans, the vomeronasal organ is better adapted to detect fluid-phase chemicals, or those suspended in solution, like in urine. Thus, if you peed your pants in fear, and an elephant got a nice trunkful of it, the elephant could possibly tell that you were afraid.

“If you approached an elephant in the wild, would they be as friendly as the elephants here?”

Elsa compares her hand to an elephant footprint
            You should never approach a wild elephant. Even as a hypothetical exercise, it’s a risky maneuver! The elephants here are tolerant of humans because they’ve developed positive working relationships with their mahouts and are accustomed to working with new groups of people (eased, I’m sure, by the fact that visitors tend to spoil them with food). Wild elephants are even more unpredictable; they could react with curiosity, disinterest, aggression, etc. Elephants are also very protective of their young and would see your intrusion as a threat should any calves be nearby. Finally, elephants in the wild have typically only had negative experiences with humans; between poaching, illegal trapping and human-elephant conflict, wild elephants currently have no reason to associate humans with anything but trouble.
If you’d like to submit your own question to our team as part of our YouTube series, “Ask an RA", please send us an email at or send us a message on our Facebook page. 


Prehn-Kristensen, A., Wiesner, C., Bergmann, T. O., Wolff, S., Jansen, O., Mehdorn, H. M., ... & Pause, B. M. (2009). Induction of empathy by the smell of anxiety. PLoS One4(6), e5987.

Stoeger, A. S., Mietchen, D., Oh, S., de Silva, S., Herbst, C. T., Kwon, S., & Fitch, W. (2012). An Asian Elephant Imitates Human Speech. Current Biology.

Sunday, January 5, 2014

When Giants Fall: Understanding Loss in Elephants

by Lisa Barrett

"The entire family of a dead matriarch, including her young calf, were all gently touching her body with their trunks, trying to lift her. The elephant herd were all rumbling loudly. The calf was observed to be weeping and made sounds that sounded like a scream, but then the entire herd fell incredibly silent. They then began to throw leaves and dirt over the body and broke off tree branches to cover her. They spent the next two days quietly standing over her body. They sometimes had to leave to get water or food, but they would always return." 
–Martin Meredith, elephant researcher.

Elephants investigating a fallen friend.

The Think Elephants International (TEI) research team is passionate about studying elephant behavior and cognition. Not only is it very interesting to learn about the cognitive capacity of the planet’s largest land mammal (and an endangered one at that), but our work also serves to remind us that we are not the only intelligent species on the planet.

In one of our most exciting studies, Dr. Plotnik and his colleagues showed that Asian elephants could recognize their own reflection in a mirror. Such a capacity suggests that, like us, elephants may have a concept of Self. Could this ability extend to a concept of loss or death as told by anecdotes of elephant funerals and mourning rituals? Do elephants experience grief like we do? Anecdotes like the excerpt above, in which an elephant stands by a deceased relative for hours, and even stories of animals grieving the death of a human (like well-known “elephant whisperer” Lawrence Anthony), certainly seem to support this idea.

Do elephants form funeral processions as this photo suggests?

Little empirical evidence exists to refute or uphold theories about animal emotions—and elephant emotions in particular—because it is difficult to say for sure what an animal may be thinking or feeling. However, one study importantly showed that African elephants will investigate the bones of deceased conspecifics (McComb et al. 2006). In fact, these elephants showed higher levels of interest in elephant skulls and ivory than in natural objects or the skulls of other mammals. Furthermore, elephants did not exhibit selective interest in remains of relatives over unrelated individuals. Perhaps unsurprisingly, this evidence suggests that there is something about elephant bones in particular that intrigues herd members.

Do elephants feel a special bond with one another that might allow them to develop a feeling of grief when a friend dies? Damini, an elephant in an Indian Zoo, supposedly starved herself to death after the tragic death of a close friend. In the wild, elephants do live in very close-knit, complex social groups which may produce extremely close relationships between herd members. Furthermore, there seems to be an ever-growing list of anecdotes about targeted helping, when an individual recognizes the needs of another and attempts to help the individual, as well as mourning-type behavior in elephants. These stories remind us that elephants may be even more similar to humans than we ever thought.
Unfortunately, emotions are difficult to objectively prove, as science can only measure what we think are signs of emotions. For example, while elephants do technically “weep” (since they do not have tear ducts they must lubricate their eyes by secreting tears, thereby appearing to cry) and make “crying” sounds, we don’t know that they do so as an emotional response. Nevertheless, anyone who has spent significant time with an elephant will tell you that these individuals seem to have complex emotional lives.

Normal elephant tear secretions sometimes make elephants look like they are crying.
Photo by: Lisa Barrett

At TEI, we are continually finding similar social behaviors between humans and elephants in our investigation of convergent evolution (read about our cooperation study here: We may never be able to (accurately) think like an elephant to prove that they experience grief like we do, but TEI’s research on how Asian elephants navigate their world is vital in creating a more accurate representation of the elephant mind. You can learn more about what it means to “Think Elephants” here: