Monday, July 21, 2014

Less than glorious introduction of a grad student who finally escaped the lab


Hello all,

My name is Sarah, and I’m a graduate student who will be in the field this summer and fall. I am usually in the lab working with all the lovely poop and blood samples that come from the hyenas out here in the Masaai Mara, but I have escaped the flourescent lighting and pipettes to spend some quality time with my study animals! 

My research focuses on the biological basis of individual and sex differences in aggressive behavior. (In other words: what is going on in your body that makes you want to fight your friends and family to the death for that last cupcake...or last piece of wildebeest flesh, if you’re a hyena?  And why might one sex resolve the situation with some well placed glares while the other draws blood?) You might already know female hyenas are more aggressive than male hyenas, which is unusual for mammals. We also see a wide variation in aggressive behavior between individual hyenas, with some generally being brattier than others. I’m trying to understand which processes in the body and brain cause some individuals to be more aggressive than others.

(Eg. What is going on in this girl's brain that makes her such a punk??? Photo by Kate Shaw)


       As hyenas get older, their social rank (which is inherited from mom) primarily determines how much aggression they exhibit. Low ranking animals risk injury if they attack a higher ranking animal because other hyenas will side with the higher ranking hyena in the dispute. 

(Two higher ranking hyenas gang up against a bigger, but subordinate hyena. Photo by Kate Shaw)



I want to measure aggression before the hyenas know any better, so I will be observing cubs that haven’t learned their ranks completely. This way I’ll be looking at behavior that is reflective of biological (ie. innate/natural) differences in aggressiveness and competitive ability. Later, I can go back to the lab and measure chemicals (such as hormones like testosterone) in their blood and poop to see if it correlates to their aggression levels.

(Cub fights are exciting because they show how aggressive cubs are before their rank influences their behavior too much. Photo by Kate Shaw)


While I’m in Kenya, I will set up situations in which the cub’s competitive sides can shine. This should be easy. All I have to do is present them with something they find tasty. Then, I sit back and watch adorable hyena cubs tussle over the treat.

Disclaimer: The sort of fighting we’ll see with the cubs is normal, and most of the aggression consists of threats (like a human glare) and chasing. The worst thing that happens is a cub gets scared enough that it will stop trying to get powdered milk. They won’t be competing more than they would normally. They’ll just be competing in front of me!

The set up for my experiment is as follows:
Step 1: Turn cubs into snack junkies

This one was easy. Cubs looooove powdered milk, so I’ve been merrily dumping it out of the car at dens where they can lick it up to their heart’s content. We want every animal to recognize and be excited about the powdered milk, so when we start the real science, they all want to fight over some milk.

(Cub with powdered milk)


(Cubs waiting for delicious milk to start falling out of the car)


Step 2: Find a good situation for the experiment

I’m going to need multiple cubs present to fight over the milk, and none of their mothers. A cub might be braver and more aggressive if they know their mamma is there to back them up.

Seems simple enough right?

Nope! This is usually what I find when I go to dens in search of motherless cubs:

Nothing..



Or everyone’s mom is here (the big furry blobs are moms)...

(So cute...so unhelpful)





Curse hyenas and their excellent mothering skills!


But still, with enough patience we finally found the perfect situation - lots of cubs hanging around the communal den without a mamma in sight! Perfection.
So, onto step 3.

Step 3: Put out the milk near the den.

Here I put the milk in an area the size of a medium suitcase. This is a small enough area that an ambitious cub will think it’s possible to hog all the milk, but large enough to make guarding the food a very difficult task. I can then watch the fights that ensue between the little junkies and test how well they compete for a valued resource.

Success! (The powdered milk is in the white stuff in the front center.)


Step 4: Sit back and watch the cubs compete over the milk

So now its simple, right? I put out the milk powder, it’s a great situation, and I have a bunch of little junkies. Well, apparently not because I sat at the den for 2 hours watching cubs run in and out of the den hole, romp around with each other and nap, and not ONE of them noticed the milk powder which was RIGHT IN FRONT OF THEM.

Sigh.

(Get your act together and find the milk, you darn cub)



In the words of my surprisingly-wise-at-times older sister (also a scientist), “If it was supposed to work the first time, they wouldn’t call it REsearch. They would call it search.” With that comforting thought in mind, I will keep toting powdered milk around in the hope that the hyenas start to feel more accommodating.


In the meantime, I had lots of time to take absurdly cute photos of the little punks ignoring the milk. Enjoy! 







P.S. Since I wrote this out, I've gotten a couple trials. Yay! Soon I will tell you all about it.)

Tuesday, July 15, 2014

A shy, long-eared cat

The most exciting animal sightings for us are not usually the ones that have tourists jumping up and down. Given that we study hyenas that might seem kind of obvious! But also, living here allows us, or at least has allowed me, to look beyond the large, majestic animals to the smaller, shyer, or rarer ones. I now always get really excited when we see rare animals such as unusual birds or shy, small mammals. Most of these animals I did not know even existed until a few months ago.

Recently, I had my best serval sighting yet. Servals are medium sized, spotted cats with large ears. They use their ears to pick up sounds made by birds, rodents, and other potential prey. Servals can even hear noises made by their prey underground! Their long legs help them reach deep into holes and pull out their prey. At the same time, servals can jump high into the air and bat down birds!


The serval we saw was walking along a track in one of the marshy areas of our North territory. She or he was very calm and just let us follow her along the track for a few minutes. She paused for a bit and drank from a puddle before moving off into the tall grass and out of sight. I always feel so privileged to have such wonderful sightings of these more unusual or shyer animals.

Thursday, July 10, 2014

Run with your inner spotted hyena spirit!

Hello! My name is Hadley, I have been an RA in the Talek camp for the past year. Back in October, the hyenas inspired me to write this message to wish my college cross country team luck before their conference championship meet:

Jambo Team!!

As runners, you’ve probably heard and/or seen inspirations for racing drawn from cheetahs or lions, drawing on the speed and strength of these well known charismatic mega fauna.

This is not going to be one of those inspirations. As cross country runners, you hardly want to arouse the speed of a cheetah…we all know that insane sprints at the beginning of a race does not bode well for the other 5-7km. You also don’t really want to evoke the lion because…well…you can do better. Lions and cheetahs are what are called ambush hunters…they lie and wait, and wait, and then burst, pounce, and kill with a mighty bite to the neck. Coach would never approve of waiting, and the pounce/kill bite just might get you disqualified.  

Who you want to channel for Conferences tomorrow is...can you guess where I’m going ; )…the SPOTTED HYENA! Since Walt Disney didn’t do this magnificent creature any favors, please let me share why racing like a hyena is your best animal strategy.

Hyenas are what are called endurance hunters – they chase. A spotted hyena can lope tirelessly for miles upon miles, can hit top speeds of 60kph, and can pursue prey for several kilometers at close to that top speed (50kph). Most animals are unsuspecting of the hyena’s speed and especially their endurance, falling prey to the hyena’s prowess through sheer exhaustion. Hyenas can hunt alone, even taking down a bull wildebeest, but also can hunt cooperatively in packs and will do so to ‘circumvent the determined defense of herds/families’.

Are you seeing why channeling the spotted hyena will be your greatest advantage tomorrow? Not wasting time with waiting, not putting full energy into one burst, (not using a kill bite…) but rather calling forth endurance, bursts of high speed, determination, the element of surprise, and strength when alone but far greater when as a group.

Coach has told us all to “Be an eagle!” and to “Fear the Gopher”. Tomorrow, be that eagle, strike fear in the other teams as the Gophers you are….and channel your Spotted hyena spirit for the calculated, passionate, grueling and rewarding race you’ve all worked so hard for.

Whooping (the infamous Spotted hyena vocalization) for you from Kenya,

Hadley

Monday, June 30, 2014

Jackals: Small but feisty


This morning we came across a nice tasty wildebeest carcass with some subadult (ie. teenage) hyenas feeding on it. As far as carcass feeding goes, this was a pretty calm morning for the hyenas (No one got bullied over food TOO much). Really, the drama surrounding the carcass was ALL jackal drama, which inspired me to write a something about these gutsy little dudes.







If we find lions or hyenas feeding on a carcass in the Mara, we are very likely to find some diminutive jackals running around in the background. While the larger predators are often busy fighting with each other, the jackals can often fly under their radar, darting in and out of the group feeding on the carcass and grabbing small scraps.


These jackals were agile enough to grab some scraps despite the annoyance of the hyenas.






They are surprisingly gutsy with larger predators. (Keep in mind, jackals are the size of a small fox (~ 13-33 lbs), as opposed to lions (~ 240-400 lbs) and spotted hyenas (~ 100-180 lbs). Recently, I saw an injured lioness guarding a carcass from a couple hyenas. She lunged at the hyenas, who promptly ran away, giggling frantically. After that, a lone jackal jauntily ran up to her and stared from a few yards away. After a few minutes of a stare down between the two, the jackal finally thought better of it. Still, he/she made a better show of it than the hyenas.

The lioness is hiding in the bushes on the left:


Some extra reasons jackals are excellent:

They’re survivors – Jackals basically eat whatever whenever, which makes them successful in areas where other carnivores may suffer.  While they’re definitely game for carrion, it only makes up 3-18% of their diet in the Serengeti. They also eat insects, rodents, snakes, baby antelope, and will start adding more fruit to their diet when vulnerable prey are hard to find. They can even do very well in areas with lots of humans, because they will happily eat our trash, scraps, and (sadly for the farmers) small domestic animals. 


They’re wily- The will follow hunting lions and wait for them to make a kill, then dart in and grab some food. In the Kalahari Desert, they will also follow brown hyenas, who are extremely good at finding carrion, and try to pilfer off them.

They’re always game for a fight – At our carcass this morning, the jackals spent a good portion of their time attacking the vultures and marabou storks, large scavenging birds who were also trying to nab some food. We even saw some of the jackals jumping in the air after the birds when they tried to get away.



In the Kalahari, jackals have been known to play “tug-of-war” with brown hyenas, with several jackals pulling at one end of the carcass while a hyena pulls at the other. They’ve even been known to nip hyenas on the bum and dash in to grab a scrap when the hyena whirls around to attack. I myself would think twice before nipping a hyena on the butt, but not jackals...

We had a little bit of tug-of-war going on this morning:






The jackals that fight together stay together: Jackals are generally monogamous – staying with the same partner for years. Together, they will defend their babies from hyenas by nipping their haunches, defend their territory from other jackals, and hunt together.
If two jackals hunt together, they can take down a baby antelope 67% of the time, even if mom is defending it.




And, of course, they are adorable:





If you're interested, I got my information from these sources: 

Estes, R.D. 1991. The Behavior Guide to African Mammals. University of California Press. Berkeley, CA.

Kaunda, S.K.K., and J.D. Skinner. 2003. Black backed jackal diet at Mokolodi Nature Reserve, Botswana. Afr. J. Ecol. 41: 39-46.

Mills, M.G.L. 1990. Kalahari hyaenas: the comparative behavioural ecology of two species. London: Unwin Hyman.

Owens, M. J., and D. Owens. 1978. Feeding ecology and its influence on social organization in brown hyaenas (Hyaena brunnea, Thunberg) of the Central Kalahari Desert.  E. Afr. Wildl. J. 16: 113–135.

 Pereira, L.M., Owen-Smith, N., and M. Moleόn.  2014. Facultative predation and scavenging by mammalian carnivores: seasonal, regional and intra-guild comparison.  Mammal Rev. 44(1): 44-55.

Wyman, J. 1967. The Jackals of the Serengeti. Animals 10:79-83.




Michigan State University | College of Natural Science