Wednesday, May 27, 2015

The Lion Thief

Spotted hyenas often get a bad rap in comparison to the other Kenyan carnivores.  They are often mislabeled as cowards who do not hunt but scavenge for their food.  This is an incorrect assumption that has been proven wrong by research done in this lab.  Spotted hyenas hunt and kill around 80 percent of their diet (Holekamp et al. 2011).  They are efficient hunters that do not have to rely on scavenging for survival.  I recently was able to experience this first hand while out on observation.

The setting was Ashlei’s last time on obs before she headed back to the States.  We were hoping to see some of our hyenas and maybe some other large mammals, so Ashlei could see them one last time.  Our luck started off pretty well when we spotted a couple of adult and sub-adult lions.  We moved on quickly from them because lions are just not as neat as hyenas.  After driving less than a kilometer we came upon one of our hyenas, Roosevelt.  She was meandering through a group of Thomson’s gazelles.  We were about to move on when Roosevelt perked her head up and eyed a baby gazelle.  Within seconds the chase had begun.

Roosevelt closing in on the baby gazelle.

The baby gazelle has no chance.

The chase is over.  Nothing like a baby gazelle for an evening snack.

While Roosevelt was munching on her evening snack, no one, including Roosevelt, noticed that one of the adult lions from before had somehow noticed the commotion.  

Oblivious to the lion's presence Roosevelt continued to chow down.

 The lion snuck up right behind Roosevelt and then… 
video

Another misguided assumption is that hyenas are often looking to steal the kills of lions.  It is actually the lions that are the bullies and steal the hyenas’ food.  Not only do lions steal the food of hyenas they are the leading cause of mortality in hyenas (Watts and Holekamp 2009).  Hyenas are very self-sufficient and do not deserve the negative labels that they are given. 




Holekamp, K.E, Smith, J. E., Strelioff, C. C., Van Horn, R.C. & Watts, H. E. (2011) Society,        demography and genetic structure in the spotted hyena. Molecular Ecology. 21: 613–632.

Watts, H. E. & HolekampK. E. (2009) Ecological determinants of survival and reproduction in the spotted hyena. Journal of Mammalogy. 90:461-471.

Monday, May 25, 2015

Just Another Night in the Bush


Picture yourself in your tent in the beautiful Mara Triangle, going to bed for the night after a long day’s work. It’s a cool night, with a nice breeze coming in through the screened windows, and in the distance you can hear calls from various animals, lulling you to sleep.
Sometime in the middle of the night you’re woken up by a light rain on the tarp above you, but you quickly start to drift back to sleep. Except…there’s something biting you. They’re crawling all over you, maybe the sound on your tarp isn’t rain? You fumble for your head lamp to see what’s going on, all the while trying to brush off whatever it is that’s on you, and as the light goes on your stomach drops; there are thousands of Siafu crawling all over you and your tent. You take the only way out you can think of, you run for the door.
Siafu is the Swahili word for ant, however it commonly refers to a specific type of ant known as the Safari Ant or the Driver Ant. 
Safari Ants - Photo by: Eli Strauss
Safari Ants Swarming - Photo by: Eli Strauss



And here's a short clip of the ants in action, taken by Eli Strauss: https://www.youtube.com/watch?v=lPK5lGIdOeg (much cooler in HD)

These ants are found primarily in East Africa, and are fairly easy to distinguish from other ants. They are normally seen traveling in large lines about 20 ants wide, with the smaller ants in the middle and the larger “warriors” on the outside. Although all of these ants have pincers and are quite capable of attacking for food or when they feel threatened, the warriors are significantly larger with much stronger pincers as well as a stinger. In their lines, they’re fairly easy to avoid; such a large number of army ants tends to catch one’s eye from far enough away that you can simply step over the line. If you’re unfortunate enough to come across a line in the dark, or while you have your head in the clouds, however, and if you step in it, there’s not a whole lot you can do but try to shake them off and hope you didn’t have any warriors crawl up your leg. If you’ve seen this happen to somebody, you can really appreciate where the expression “ants in your pants” comes from.
They aren’t always so easy to avoid. When they’ve been scattered by something in their path, or when they find something to eat, they begin to swarm (as they did in my tent on that lovely night). They’ll scatter all over the place so that stepping over them is no longer an option. Luckily, they’re not poisonous, they aren’t lethal and their bites are by no means excruciating. So, looking back on the experience, I can’t help but laugh and feel fortunate. As far as animal invasions in my tent at night go, it could have been a lot worse than ants.

Saturday, May 23, 2015

Life and Death in the Happy Zebra clan


Before reading this post, be warned that there are some graphic photos.


Sports Illustrated, a Happy Zebra subadult
The last time I saw Sports Illustrated alive, we met while I was coming back from a solo obs session. He was napping in the road, and I stopped to see if he would make some room for me to pass. He looked at me for a second before getting up and walking towards me and past the car into the night. He came so close that I could have reached my hand out and touched him.

A week later, he was seen emaciated and staggering, barely able to move. Another week passed, and we found him dead.

We were headed to the new Happy Zebra communal den when we found two subadults; Sports Illustrated was dead and Walk the Plank (we just call him Plank) looked like he would be dead momentarily. Plank was tiny and fragile, and walked with the same staggering gait that we had seen in Sports Illustrated a week prior.

Plank investigating Sports Illustrated's body
Plank staggered over to Sports Illustrated and began to half-heartedly nibble at him for a few moments before collapsing nearby. When we got out to collect Sports Illustrated’s body, Plank was almost completely non-responsive to our presence.

We drove home to do the necropsy on Sports Illustrated with the knowledge that we may have to do another on Plank shortly.

Plank half-heartedly chewing on Sports Illustrated
It was a few weeks before we saw Plank again; he still looked terrible, but he was feeding on a topi carcass and seemed to have improved. He was even able to keep Higgs-Boson, a lower-ranking Happy Zebra subadult, from feeding.


Plank feeds on a Topi carcass while
 Higgs-Boson waits his turn
Now Plank has once again become a regular visitor at the communal den. His growth has been significantly set back by his period of poor health, but he is fat and happy and appears to be on the path to recovery. 
Plank happily rolling in something stinky at the
Happy Zebra communal den

Michigan State University | College of Natural Science