Because hyenas are great, and beautiful, and cute AND smart.

 

Let’s add a French touch to the hyena blog!!

I joined Kay’s lab last winter, for a two-year post-doc. My name is Agathe (in French, you would pronounce the A as you say it when the doctor is looking inside your mouth, and then pretend there is no H after the T, as it is usually silent in our beautiful language).

Ok, enough about French pronunciation. I’ve been in the Maasai Mara since last September, shame on me for not writing a blog post before, no excuse.

I’m an ethologist, meaning I’m studying behavior (of animals but also of human beings). My project here focuses on cognition, more specifically behavioral flexibility. Let me explain. 

   So, as you probably know, as primates, we are one of the species that can claim one of the biggest relative brain size among mammals. However, you would be surprised by what some birds can do, or even honeybees (Komischke et al, 2002). But, this depends on what kind of cognitive tests you are considering. In fact, cognition can be divided in two categories: physical and social cognition. While the first helps us deal with inanimate objects, we are able to understand our conspecifics intentional actions, perception and knowledge thanks to the latest (Herrmann et al, 2008). Of course, social cognition is most useful when living in a big society, which means frequent encounters with conspecifics. As a matter of fact, social complexity could be what drove individuals to have bigger and bigger brains by evolution (Byrne & Whitten, 1988). This is because living in a complex society enforced the need to understand its social rules, or to predict/understand the intentions of your conspecifics, especially if they’re higher ranking. As an example, when you are a middle ranking animal, you better be able to tell if that high ranking female approaching your kid is going to bite its head off, or just sniff it on her way and go. Or, before you come to rescue your BFF who’s being bullied, you want to make sure that his tormentor is not higher ranking, because he will remember you next time…

   You probably know by now how great our hyenas are, and like monkeys, they are able to recognize any member of their clan. Therefore they can remember their social status and choose to join someone in a brawl based on previous interactions and social affinity (Holekamp et al, 2007). Overall, they meet the criteria to fit in the social intelligence hypothesis.

   

   On the other hand, we know very little regarding their physical cognition (however, see previous work on our hyenas here), mostly because majority of that research focuses on primates. The social intelligence hypothesis predicts a high level of physical cognition along with social cognition. The key is to choose a task that can be done by several species, so that a wide comparison between species is possible. Let’s forget about IQ tests right away, only a chimpanzee would give the pen back when he’s done, and even a rather civilized baboon would eat it. Behavioral flexibility, the ability to adapt one’s behavior to solve a problem, is a good measure of general intelligence and can be adapted through various tasks.

   The hard part was to choose a task that hyena could solve without the use of hands, unlike their primate friends. Moreover, wild hyenas are very cautious toward man-made objects, hence I chose a task that they could do in several steps, to eliminate any bias of novelty on their ability to solve the task. So, to test their ability to display flexible behavior, I’m using a reversal learning test where the hyenas have to pull ropes to get access to meat, as a reward. They first have to learn to discriminate between two colors (black versus yellow), one associated with the reward, the other one associated with the absence of that reward. Once they have learned that, the rewarded and the non-rewarded colors are reversed and they have to suppress one behavior in favor of another to get the meat.

On this video: from the inside of the box: Decimeter, a subadult high-ranking female, comes and pulls the rope. It's her first time though, so she is kind of freaked out instead of taking the meat right away. 

  Conducting an experiment on wild hyenas takes time, especially when I have to find them across their wide territory and get them to interact with the device. After a very long habituation phase, I have now started the learning phase, trusting that my beloved subjects will learn it quickly (because I believe that they are indeed smart). Then, the best part begins: reversal learning!

Unlike Decimeter, KENG is used to the box and loves it. You can see  that she already got the meat on the right side. Here she is trying to pull the yellow rope, but the left tray is blocked : she now has to learn that only the black rope will get her meat! 

  Another time I’ll tell you how it went with lions (we could not find any hyenas that day, and I was curious…).

References

Byrne RW, Whiten A (1988): Machiavellian Intelligence..Oxford, Clarendon Press.

Jerison HJ (1973): Evolution of the Brain and Intelligence. London, Academic Press.

Hermann et al (2007): Humans have evolved specialized skills for social cognition: the cultural intelligence hypothesis. Science (317), 1360-1365.

Komischke et al (2002): Successive olfactory reversal earning in honeybees. Learning & Memory (9), 122–129

Holekamp et al (2007): Social intelligence in the spotted hyena (Crocuta crocuta). Phil. Trans. R. Soc. B (362), 523-538. 

Target, Interrupted

By Moira Donovan, IRES 2013

Hey there! I’m Moira, one of the new IRES students assisting the lab this summer. I’m currently stationed in the Serena Camp, helping with “Target” trials. “Target” is a life-size styrofoam model of a hyena, made by a company that manufactures archery targets—hence his name. Julie, the graduate student whose research I am helping with, uses Target to test hyena “boldness.” Her research focuses on social intelligence (how well a hyena interacts with others in a group environment) and personality aspects that might contribute to it. We measure boldness by observing whether a hyena approaches Target and when the hyena realizes Target is not an actual hyena.

In order to conduct a Target trial, we first need to find a lone hyena traveling a predictable path. We then drive ahead of the hyena, deposit Target along its path, and wait nearby to observe what the hyena does. Two nights ago, Julie, Lily, and I went out on our usual evening observations in search of an opportunity for a Target trial. We drove to the Happy Zebra Clan Territory, hoping to find an unsuspecting individual. I never imagined I would be so lucky as to experience what happened next.

Target and Moira

Soon after entering the territory, we spotted a single hyena loping along. We sat in our seats, deciding whether this would be a proper candidate for a trial, as the hyena rushed across the road and continued in a straight line. Clearly, this one was headed somewhere important. As Lily turned the Hilux off-road and we began to pursue, the urgency of the chase dawned on us – we could hardly keep up at 25kph. We hit a rocky portion, forcing us to slow down, and we were sure we would lose sight of the unidentified hyena. As we maneuvered around the rocks we saw three more hyenas join the first, bolting toward a herd of Cape buffalo. On the outskirts of what must have been 200 buffalo, we saw the hyenas and knew we were going to witness something extraordinary.

Spotted hyenas typically prefer to hunt alone rather than potentially lose their meal to a higher-ranked individual. This time, however, we spotted at least ten individuals when we got there, and a few others arrived in the following hour. Despite our difficulties recording hyena behavior through the darkness, rain, and tall grass, the effects of a large hunting party were clear. While two hyenas warded off an adult buffalo’s charges, several others closed a circle around a fallen calf and began to feed, taking advantage of their allies’ efforts. Once the adult buffalo gave up on trying to protect the calf, what followed may have seemed to the untrained eye (like mine) like a free-for-all between the hungry hyenas. But if you can observe closely, and if you know the identity and social status of each hyena, you can see method in the madness.

Higher-ranked individuals have priority of access to resources. In spotted hyena society, this means that feeding order is dictated by matriline: the highest-ranked female and her relatives eat first, then the next highest-ranked female and her relatives, and so on. The more dominant clan-mates chase off lower-ranked individuals who attempt to feed before their turns. Since immigrant males are at the bottom of the hierarchy, the three that were present were pushed to the outskirts and could only feed on scraps. As this event unfolded on just my the third night in the Mara, I had no clue as to which hyenas were who, but followed Julie and Lily as they called out behaviors and IDs while I filmed.

After the excitement of the hunt comes the analysis of the video. Because of the darkness and chaos of the hunt, we were unable to accurately identify individuals or behaviors at the time. Video recordings of events can be watched over and over again and at slow speed, to allow us to see what the hyenas actually did that night. One hour of video footage equated to three solid days of analysis. For analysis, all of the important behaviors performed by the hyenas are recorded in a text shorthand transcription for later reference. In order to record behaviors, however, one must be competent in identifying individual hyenas. I have not yet reached competence in that regard, but look forward to the day when my skills allow me to argue with another research assistant about who will drive during and who will transcribe after our observations.

In the past week, I have learned that most days in the field do not include so much drama. Although we didn’t manage to do a Target trial that evening, such interruptions in data collection add to the unpredictability of the field. In a place as new to me as the Mara, though, it’s the small and seemingly unremarkable moments that renew this experience, day after day. So, until I see another kill, the everyday beauty of the Mara – from the sunset reflecting off the grass to seeing the cutest baby elephant or a species of bird I never knew existed – keeps me fixed on this place. In the meantime, I am hoping for some Target trials….

When Lions Don't Bore You to Tears

Most hyena researchers that come out here have a healthy respect for lions but, on average, there is no love lost between Fisi Campers and Mara lions. They steal our hyena's food, kill our hyenas, and for the most part, are just plain boring. Call us biased or elitist if you will, but hyenas are much more beautiful, much more intelligent, better hunters, and much more interesting in their behavior and biology. In my seven months out here, lions have impressed and fascinated me only a handful of times. Most of those times have been during lion/hyena interactions (I'm convinced that it was the hyenas bringing out the best in the lions and that the cool behavior really didn't have anything to do with the lions at all). A few times though, lions have been interesting all on their own. In the spirit of fairness and unbiased scientific discovery, I thought I would share a few of those stories with you.

One of the lions prides that I have warmed up to is a large pride that hangs out in our Fig Tree and Prozac territories. I've managed to find them interesting due to a few unique individuals that they have and a few unique behaviors that I have witnessed. Their subadults actually play instead of just laying around all day! Amazing!

This adult female has obviously earned my respect. All it takes is getting your face gored by a warthog



The other cool thing that this pride has going for it is a propensity for climbing small trees in a "clown-car-ish" fashion. Believe it or not, there are 8 lions in this little tree/bush.


In West Territory, there was this one time when I saw a lion actually stalking something! It failed miserably, but I was proud to see a lion actually trying something other than sleeping.
That same morning, shortly after this failed hunting attempt, two HUGE male lions put forth the effort required to chase these females across the plain and out of their territory.

This last picture may not look like much but it is undeniable proof that lions really do get up from their endless napping and do something now and then. So Kay, you really should listen to Dee and go a little easier on those poor lions.

I am still looking for undeniable proof of their superior intelligence and beauty though. That might take another seven months/years.

Hyena Research on Video

The video team from MSU spent last week with Professor Holekamp and her students in the Mara. They followed the researchers and gathered video for an upcoming television show. Here are some clips from their visit.

The first video covers the Hyena Puzzle Box:


This second video is on darting the hyenas:


We'll keep you posted on when the episode of "MSU Today" will air on the Big Ten Network, WKAR and on the web. For a related story, here is Jim Peck's blog post where he writes about his arrival at Fisi Camp.

Animals have brains too (Part II)

So how can you test hyenas’ intelligence?

First, we tried sitting our hyenas down and giving them IQ tests. Unfortunately, they couldn’t hold the pens, and they ended up eating the test booklets. Back to the drawing board.

Seriously though, in order to be effective, our test had to meet a few criteria. First of all, it had to be hyena-proof. It needed to be something our hyenas couldn’t destroy, consume, or drag away.

The test also had to be something that, even with their limited dexterity, hyenas could manipulate in some way to “solve.”

Finally, the test had to represent a “novel task,” which is scientist-speak for “a challenge the hyenas have never seen before.” This way, we know the hyenas aren't just relying on some skill they already have.

Luckily, clever grad student Sarah Benson-Amram came along and developed a test that meets all these criteria. Called a “puzzle box,” it’s based on an invention by psychologist E.L. Thorndike.

Essentially, it’s a big box made of rebar (and when I say “big”, I mean “BIG…” this thing weighs about 75 pounds). The box has a swinging door that closes and locks with a sliding latch. We put a piece of meat inside the box as an incentive, close and lock the door, and present it to a hyena. Their task is to figure out how to get to open the box and get to the meat inside. Just like a Rubik’s cube or Sudoku puzzle is a brainteaser for us, the puzzle box is a way to test hyenas’ problem-solving abilities.

My favorite thing about watching hyenas interact with the box is the multitude of strategies they employ. Some bite the box; others dig underneath it. A few flip and tumble the box. Some decide that an aerial view will help, so they get on top of the box and peer down. Many hyenas try the “If I lie here and stare at it long enough, it will open” strategy. Unfortunately, I haven’t seen this one work yet.

Sarah spent an amazing amount of time and effort developing the box and working out the kinks. During Sarah’s research, 9 Mara hyenas (out of 58 who tried) opened the box. On average, a hyena needed to work on the box three different times before they could open it. One smarty-pants, Snaggletooth, got so good at the task that he was able to open the box in 3 seconds; Kent, shown below, could do it in 5 seconds.

I'm now doing some work with the box here at Serena. While all this just the tip of the iceberg, it’s certainly a promising – and interesting – way to look at animals’ intelligence.

Animals have brains too

With a few notable exceptions, humans are pretty smart. But where did our intelligence come from? Assuming you’re among the 39% of Americans that accept evolution (see this poll for some interesting statistics), you’ll probably agree that at least some of our brainpower came from our animal ancestors.

For scientists, that’s not the end of the story, it’s only the jumping-off point that raises many tough-to-answer questions. How “smart” are animals? Are some species smarter than others? Why and how did intelligence evolve in the first place? Answering these questions will teach us about the processes that govern human decisions and the ways we think about the world.

These are issues we’re interested in tackling here on the Hyena Project, since we’re under the impression that spotted hyenas are rather intelligent (and that’s not just because we love them). Our observations show that they can recognize other clan members individually - and even determine their emotional and physiological states - by sight, smell, and sound. They understand the advanced concepts of cooperation and reconciliation. Perhaps most telling of all, hyenas live in this fabulously complicated dominance hierarchy, where rule-breakers are punished by severe aggression. A hyena that can't figure out the social rules will suffer injuries or even death, so there's probably very strong selective pressure for high intelligence among hyenas.

So, it seems like our hairy, drooling study subjects can teach us a thing or two about intelligence. But here comes the problem; how in the world can we measure intelligence in animals, especially in a species like the hyena?

I love cliffhangers (especially when I know the answer), so I’m going to leave you to chew on that one for now.