Friday, April 3, 2015

The perks and cons of having a carnivore as a model species

In ethology, one Nikolaas Tinbergen once summarized research topics in four main questions:
  •  development - How an adult individual comes to display a given behavior and how that behavior can be influenced by others and by the environment he/she grows up in. How do we learn to speak? What happens if you grow up in a different country than the one you were born in? Those kind of things. 
  • function - What is this behavior for? For instance, why hyenas are whooping? (you'll have to follow/support Kenna Lehmann's research to know that answer to that question). Why cats purr? And so on...
  • evolution - How/when did a particular behavior appear in a particular species? Why do chimpanzees use hand gestures to communicate but vervet monkeys don't?
  • causation - How does that work? What happens in your puppy's brain when you are training him not to pee on your favorite rug? How does he remember it? (Or will he ever??!)
Wherever your interests lie, you have to choose the right model species to answer those questions, or let's be honest: try to answer one of these questions. 

In my research experience, I've had the opportunity to work on different projects and therefore study different species: I was first introduced to research with monkeys, I then switched to Japanese quails during my days as a PhD student, and I am now obviously working on hyenas. 

Each one of them have good and bad sides. Let's consider their diet for example. 

Cercopithecines monkeys

Those are the baboons, macaques, vervets, guenons, mangabeys, etc. 
At this time, I was investigating how handedness evolved among primates (as in human beings, do monkeys have a preferred hand? Which one? In which situations, etc.)

My monkey friends belonged to three closely related species, with different locomotion habits (from terrestrial to arboreal). I used the same experiments with individuals of all three species to compare the results.

Red-capped mangabeys

Mangabeys spend most of their time on the ground, like baboons, but they are a little bit smaller like a border collie probably. They are very playful and will occasionally pee on a visitor or an experimenter (I don't know how I avoided it for over 2 years). I particularly like their white eyelids, which they display as a threat, or when they are trying to bully you into giving them that piece of apple that you have in your hand. 
They eat vegetables and fruits everyday, but what they REALLY love is....peanut butter. Their great great grandparents were born in West Africa though, not the US.
So I stuck some peanut butter in tubes and let them use their fingers to get it. 
George looking if, by any chance, there is still
some peanut butter left in that tube

de Brazza's monkeys

Like mangabeys, de Brazza's monkeys eat mostly fruits and vegetables. They also are very cute with their nice orange crown and white beard...and yes, Pimprenelle is a female. They are just a little bit smaller than the mangabeys.
Pimprenelle enjoying her peanut butter fix

Campbell's monkeys

Now that's another story. 
Campbell's monkey are about the size of a vervet monkey, the annoying ones we have in camp. I'd say they're about the size of a raccoon. 
They spent most of their time up in the trees. Like mangabeys and de Brazza's monkeys, they eat mostly vegetables and fruits (and the occasional fly). Now, you would think, like their cousins they must love peanut butter since they eat the same food. 
Nope. Not. At. All. It took me some time to find a mixture that would stick in the tube, and one they would want to give a little effort for. 
Banana jam? Nope, not sticky enough anyway. Banana purée mixed with peanut butter? Nope. Mashed potatoes? Hum...maybe. Mashed potatoes with sunflower seeds? Oh, ok then. 

Lowina hasn't got it yet...she will eventually

Japanese quails

Two years later, I was studying quails as a model to investigate chronic stress on development in birds. They eat the same things as chickens do, mostly seeds mixes and granulates. Not as fun as a monkey, but still cute. And so small!

Day old chick. Super cute, eh? And soooo soft.

      That little guy is growing so fast! 15 days after hatching, and already starting to have grown-up feathers. 

Now she's a lady! Five weeks and ready to lay eggs. 

Everyone has weaknesses, right?
Cookies? Gummy bears? Strawberries? Chocolate? Ice cream? Butter? (hey, no judgment!). Well, their weakness is worms:

A mealworm (not to scale haha)
I designed an experiment that was meant to test how fast they would learn to come eat their favorite food from my hand. Very good idea...but it meant that I had to stay 2 minutes with one of those in my outstretched hand, trying to get away from his cruel fate in whichever direction it could, sometimes in my sleeve. Well, I survived. Not a super pleasant experience but still ok. I preferred getting my hands sticky with peanut butter though.

Spotted hyenas

Here they come! I assume that if you're reading this blog, it means that you are already convinced how great hyenas are. Although monkeys are super cute, hyenas can hardly be jealous. For my experiments here in Kenya, I needed some food to bring the hyenas to my device and to interact with it. It's common knowledge that hyenas eat meat. They hunt and they like fresh meat, but they won't turn down any kind of free meat either. 
As I used peanut butter with monkeys and worms with quails, I used meat obtained in the neighboring Maasai town. 

Talek Maasai Butchery
No refrigerator nonsense in the Mara

I will spare you pictures of the actual pieces of meat I got. No need to buy a nice steak for the hyenas: stomach, intestines, esophagus, or liver is fine enough for them. 
Ah, but I didn't want the hyenas to have a full belly (although that is quite a task to achieve) on the first trial. They had to come back several times to my box, so no big pieces, let's cut that in smaller pieces:

My meat bucket and me
"Why didn't I cut that meat yesterday, whyyyy?"
To be honest, Benson, Wilson and Chief would often pity me (and also be critical about my skills with the machete) and helped me with the nasty meat cutting.

As you know, somedays it's hard to find hyenas to test. I will let you imagine how my bucket smelled after just a couple days. I'd like to thank all my fellow fisi friends here for enduring that smell in the car and for helping me setting up my experiments (almost) without complaining. For all the duration of that experiment, they were always supportive and helpful, thank you guys!!!

Photo credits: Floriane Guibert, Agathe Laurence, Chase O'Neil

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