Hyena Myth #1: Busted

Let’s face it, hyenas are weird. And, while their bizarre qualities are what we scientists can’t get enough of, they’re also the reason that hyenas have been forever loathed and misunderstood. There are more myths surrounding hyenas then I can count, but we’ll start with one of the strangest and most common....

Yesterday, a safari guide stopped us on the road. He said, in a hushed tone (like many guides, he liked to pretend he knew everything and didn’t want his clients to hear him admitting uncertainty), “Is it true that in hyenas, males and females are, you know…one?” It wasn’t the first time I’d heard this question, and I’m sure it won’t be the last.

While males and females are not, in fact, “one,” hyenas do have a definite physical peculiarity: the two sexes have nearly indistinguishable genitals. That’s right: female hyenas have “pseudopenises” - completely capable of erections – as well as “pseudoscrotums” made of fatty tissue. Don’t say I didn’t warn you…I told you they were weird.

In fact, if I didn’t know any better, I’d buy into this whole male=female thing too. Check out the hyena below…that, dear readers, is a female hyena in all her male-mimicking glory.


Imagine seeing that hyena nursing a cub or – stranger still – giving birth. That’s why, for millennia, people have thought that hyenas had both male and female organs, a biological phenomenon called hermaphrodism. This sexual ambiguity, popularized by writers from Ovid to Hemingway, has made hyenas the subject of confusion, fear, and mistrust.

While hermaphrodism may seem like material for freak shows and science fiction novels, it’s actually somewhat common in the animal world. Picture this (I liked Leslie's hypothetical "Carl" story, so here goes): you’re a female sea cucumber that lives on the ocean floor and rarely comes into contact with another sea cucumber. But, you'd really like to fulfill your biological destiny to mate before you die. You may wait days, weeks, or months to see another sea cucumber…so let’s hope it’s a male! OR you could be a hermaphrodite with the potential to be both male and female…that way, no matter who you run into, you’ll be able to fill the ocean with lots of adorable baby sea cucumbers.

However, hyenas certainly aren’t solitary, and they encounter members of the opposite sex dozens of times a day, so hermaphrodism wouldn’t be a real advantage here. Instead - despite all appearances - hyenas follow the standard mammalian pattern of having two distinct sexes: males and females. While scientists as far back as Aristotle have tried to clear up the confusion, their rational arguments have been drowned out by images of female hyenas’ uncanny “maleness.”

Of course, if you’re even slightly scientifically-minded, this brings up the obvious question: why do females have pseudopenises? Well, we're still working on ironing out the details of that one. If you've got a definitive answer, let me know, and I'll have a PhD in the bag.

Kenya rejoices

Yes, I know you can’t go for 5 minutes today without hearing about election results, but here in Kenya, there’s no talk of electoral votes, senate seats, or partisan politics...there's only celebration. As much as the political commentators are touting the “historical” implications for the US, I’m pretty convinced that this morning was just as momentous for Kenyans as it was for Americans, if not more so. No matter what side of the political fence you’re on, you can’t deny that Barack Obama’s candidacy has instilled pride, hope, and a sense of unity in Kenyans.

Audrey and I gave our hyenas the morning off and went to watch the election returns in the Serena Lodge staff quarters, which quickly filled with rowdy Kenyans. When CNN projected Obama as the winner, a deafening roar broke out and free Cokes (it was just 7am, but that didn’t matter) were passed around. As we watched Obama’s acceptance speech, the room alternated between captivated silence and boisterous cheers.

For the last several months, Obamania has indeed gripped this country. Locally-brewed “Senator” beer has been dubbed “Obama” beer. In the roadside markets, kangas (traditional fabrics with bright patterns and Swahili sayings) now bear portraits of Obama and the phrase Yes We Can. As a foreigner, the first question I get is “What country are you from?” When I reveal that I’m American, the follow-up is inevitably, “So you must know Obama!”


But to Kenyans, Obama is more than just a local guy making good. After the political instability that ravaged the country earlier this year, this morning’s results reminded Kenyans that democracy is possible, and that elections can accurately reflect the will of the people. Our Serena camp attendant, Philomen, said (this is a translation from Swahili, so forgive me if I misquote you, Phil!) “Here, our election was stolen from us. In America, the right man won.”

I won’t pontificate here on whether the right man won or not. But, I will say that, after the horribly divisive events here in January, it’s been amazing to watch Kenyans unite behind a common cause. Even the bickering government has banded together and unanimously declared Thursday a public holiday to commemorate their countryman's success.

So no matter what your political views are, tomorrow you should kick back, relax, and celebrate Kenya’s newest holiday…we’ll have an extra “Obama” beer on your behalf.

It's only natural

When I posted the photo of the obese hyena on Halloween, an astute reader posed the question of if she might get diabetes from being so fat. An excellent question!

The short answer is no, probably not. First of all, hyenas can go from "fat" to "normal" and back pretty quickly...they are capable of gaining an astounding 20kg in a single meal (that's 44 lbs. for those not metrically-minded). To give you some perspective (if you still need any after reading "44 lbs."), that's about 130 hamburgers, and at least three times as much as I can eat at Thanksgiving. Obviously that's not all retained as fat, although after such a gorging they will stay fat for days (Navajo, the hyena in the picture, is just now starting to return to her normal, albeit heavy, weight).

But back to the question—can hyenas get diabetes from being so fat, even if they're only fat sometimes? Well, I'm sure it's possible, but the truth is that most wild animals don't contract diseases like diabetes or cancer. That's because the selection pressures (yes, selection as in natural selection) are too strong. In other words, if there were a hyena that got diabetes from obesity—let's call him Carl—it would probably be because Carl had a genetic mutation predisposing him to the disease. Well, Carl certainly wouldn't fare very well against the other hyenas in The Game of Life, since he would be too busy trying not to keel over in a diabetic coma. Carl probably wouldn't produce as many offspring as other hyenas. In fact, maybe Carl would die before he had a chance to produce any. Bummer for Diabetic Carl, but less of a bummer for the hyena population's next generation, because now those genes for diabetes have gone with Carl, without getting passed on. In other words, they've been selected out. This is also why animals don't typically get diseases like cancer.

Okay, so why do we get cancer? By now you have probably caught on and guessed, because if you're reading a blog about hyenas you're most likely in touch with your Inner Science Nerd, but I'll elaborate nonetheless.

Humans are subject to natural selection just like any other species, but we have a special knack for relaxing (weakening) it. We have developed a million different medicines, medical treatments, and other life-saving and life-prolonging tactics to help us overcome things that would have surely done us in a couple hundred years ago. Think about it—a few hundred years ago, if you got the flu, things didn't look good for you. If you had a difficult childbirth, you and your child were in serious danger. And if your body stopped producing insulin, well, you were pretty much out of luck. It's therefore no surprise that life expectancies were half what they are today.

Today, thanks to technological advances, we're able to look natural selection in the eye and say "Pfff! Bite me!" Okay, it's not exactly like that, but the selection that operates on us now is so weak that it can be almost impossible to detect. I've had the flu, as have most of you, and I'm confident that if I can't pop a baby out naturally, my obstetrician can come up with some kind of a solution. And although diabetes is a very serious health condition, it is now something that people can commonly live with if they take proper precautions (and live in a country that doesn't mind insuring all its citizens...whoops, sorry, slip of the tongue). As for cancer, most wild animals—like humans not that long ago—never live long enough for cancer to get them. Those that do get it die pretty quickly, so the ones that are less likely to get cancer are the lucky ones who get to pass on their genes.

I don't mean to imply that natural selection doesn't act on humans at all any more, because it certainly does. It can just be a lot slower and a lot more subtle than it used to be. This is why human overpopulation is such a problem—we've removed many of the natural population controls. But that's a story for another day.

**Special thanks to Andrew S. Flies for his input on this matter.

Ant in the pants

Here is the follow-up to the recent posts about the marauding ants in Fisi Camp. The hyena researcher was unlucky enough to have a soldier ant bite into her foot. Luckily for everyone else, she was nice enough to let us photograph her fending off the attack. I can think of a lot worse places to be bitten than in the foot!

Tragedy strikes

NOTE: The sentiment among the bloggers at FisiCamp is that we really want to give you an accurate depiction of what happens out here, and that means writing about both the highs and the lows that we experience. While I’ve tried to spare you most of the gory details, just be advised that this entry does illustrate the harsh realities of life out here. It redeems itself somewhat at the end, I promise…
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The hardest part about studying animals occurs when, all of a sudden, you’re reminded that they aren’t invincible. Despite the fact that hyenas are amazingly feisty and resilient animals, they live difficult lives.

When we spotted Geezer, we immediately knew something was wrong. He was trying to walk into a shallow water hole, but he could barely move. He was moving slowly and laboriously, and it took a long time for him to reach the edge of the pool. As he bent down to drink, blood ran down his neck from several puncture wounds, and the water around him turned red. Geezer drank laboriously for several minutes, which wasn’t a good sign - healthy hyenas don’t tend to drink much.


From the size and shape of the punctures on his neck, as well as other wounds on his back and hindquarters, we could tell that the poor guy had been attacked by lions. He’s from the Happy Zebra Clan, whose den was visited by lions not long ago. Recently, we’ve repeatedly seen a group of five large male lions in the heart of the clan's territory.


To make a sad story short, Geezer didn’t make it through the night.

Out here, we walk a thin line between being animal enthusiasts and scientists. As animal lovers, we inevitably grieve when a hyena dies. These hyenas become our family and our closest friends. We know their favorite hangouts, their friends and foes, and their funny quirks. We see them day after day, carrying on with their lives, and it’s impossible not to get attached.

Unfortunately, rule #1 in research is “don’t get attached,” because our jobs don’t just end when a hyena dies. We can learn invaluable information post-mortem, so we have to retrieve the body, perform a necropsy, and prepare the skull to be sent back to the US. As scientists, we have to (at least attempt to) distance ourselves from the situation; it’s a strange and difficult balancing act between emotion and obligation.

But, all is not lost. In an ironic twist of fate, the same day Geezer died, we had our first sighting of Quark, the newest cub in the Happy Zebra Clan. The coincidental timing of Geezer’s death and Quark’s birth was a perfect reminder that, while nature can be harsh, new life is just around the corner.

Gluttony: the second deadly sin

What happens when you eat all your Halloween candy in one sitting:

Every tree has its thorns

One of the things I noticed on my first visit to Kenya was how many plants are covered with sharp thorns. It seems trees and bushes covered with thorns are more common the those without thorns. After a week or two in the bush the soles of my shoe and sandals were full speckled with thorns. This year I have been wearing my generic crocs around camp, which are very comfortable, but provide the nasty thorns with easy access to the bottom of my foot.

The high density of animals that feed on tree leaves is one reason that so many trees have thorns. The thorns function as a defense against herbivores eating the tree leaves. As with defense in nature, a new offense will inevitably arise. Many adaptations have arisen in the savanna to circumvent the plant defenses. I think the elephants have a particularly interesting method of dealing with the thorns. They just eat them.

In the first picture below you can see the thorns in the foreground and the stripped branches in the background. The arrows are pointing to branches that have had the leaves and thorns removed by an elephant trunk. The second picture is for scale and to help you appreciate the size and strength of the thorns and how tough the elephant trunk, mouth and digestive system are. I was able to push the thorns on the branch into the log quite easily. It should also be evident how thorns of this size could easily go all the way through a human foot, some feet more easily that others.

Vote

When I realized I was not going to be in the states during the election I was quite disappointed. Surprisingly the election in the U.S.A. is a hot topic in Kenya, due to the ancestral connection of one of the presidential candidates to Kenya. Many Kenyans I have spoken with has asked about the elections and has been well-informed. I have heard reports of Kenyans getting up at 5am to watch the presidential debates.

Most of the news I get from friends at home about the elections is how nasty the campaigns have become and how happy people will be when they don't have to see another political commercial. Despite the distance of the Fisi Camp researchers, we have managed to stay acutely interested and informed about the election process. Much to my surprise, my absentee ballot arrived promptly in late September and is now on its way back to the states. Special thanks goes out to the helpful staff of the City Clerk for the city of Lansing.

(addendum)

I wasn't convinced that you are fully appreciating just how ugly marabou storks really are from my previous photo, so I'm including another one here that should hopefully do the trick.

It's all fun and games until someone gets trampled by an angry buffalo

Hyenas are very curious about other species, this much is clear. Below is a photo of a hyena investigating a marabou stork, a large scavenging bird that I like to think of as “hands down the ugliest thing I’ve ever seen in my life.”

The next photos are of a group of hyenas we saw this morning, all very curious about a sleeping buffalo. Since they’ve certainly seen buffalo before, it seemed like they were playing a game of chicken, daring each other to see who could get the closest. Although these games are usually played by the cubs and subadults, a couple adults were even getting in on the action today. It was pretty hilarious: they’d tiptoe closer and closer, and if the buffalo even twitched its tail they would all freak out and back off. Then they’d get their courage up again and the game would repeat. Truthfully, I’m not sure the buffalo was even aware that it was involved in the game, since it was facing the other direction.

But that game paled in comparison to one we saw a couple weeks ago between a teenage hyena and an adult jackal. When we arrived, the hyena was chasing the jackal, which seemed strange since jackals are not typical hyena prey. But then we realized it was just a game—the hyena was chasing the jackal round and round a big bush (which begs the question, who really was chasing whom?). Our initial impression was that this was great fun for the hyena, but not so much for the traumatized jackal. Oh how wrong we were—the hyena stopped to catch its breath for a moment, and the jackal stood, looked at it, then ran it it teasingly and darted away at the last second, just like my dog does when he wants me to chase him. The jackal did this a few times until the hyena acquiesced and the game resumed around the bush. At one point they even switched directions mid-chase without breaking a stride. Sadly, it was too dark to get any photos or videos, but I think you get the idea.

This last photo is of a stand-off between an adult hyena and a wildebeest. They stood staring at each other like this for several minutes before going their separate ways, no love lost.