AFRICA'S MAGNIFICENT PREDATORS [8.1.07]
Essay By Nathan Myhrvold
on photos to enlarge]
of the focal points, if you pardon the pun, of my recent trip to
Botswana was lions, Africa's magnificent
some of the photos are a bit gory, and one shows explicit
are the only truly social cat, living in groups called prides.
A pride is a set of females, often but not always sisters, along
with their cubs and subadult cubs. There are also one or more males,
usually a coalition of two brothers, but sometimes unrelated lions.
Lionesses are the backbone of the pride—they stay together
for many years. Males tend to come and go—the typical
time frame for them dominating a pride is just 3 to 4 years.
Upon reaching adulthood female cubs may stay with the pride.
Males never do—they disperse and become nomadic, looking
for a pride where they can challenge the dominant male and
Male lions really look the part of the "king of beasts".
Their lives are full of violence, exploitation and sex—in other
words just like human royalty through much of history. Male lions
sleep an average 20 hours per day. The females on the other hand
do all of the really hard work—killing the majority of prey,
which the males then appropriate for themselves. The main danger
males face is fighting off other males that want to take over their
pride and territory. This is serious business; most male lions die
in such fights. In between territory fights they are bad tempered
and terrorize the females in their pride. In short, they
have the lifestyle of pimps.
with wounded eye
Females, on the other hand are sleek efficient hunters. They must
kill most of the prey, which is very dangerous work. I saw three
lionesses that had each lost an eye. One, which the guides call Silver
Eye is the most aggressive hunter in her pride. In another
area we saw a lioness dubbed "Evil Eye" who had a similar
but much more recent eye problem. The eye was still swollen, giving
her a demonic look, a bit like villains in Japanese Anime. I also
saw a lioness which had lost her eye in the last couple days—the
socket was still oozing blood. Each of the lionesses had lost their
right eye, which suggests to me that lions might be right handed—technically
this is called laterality. Presumably right favoring lions would
approach prey preferentially from the right, leading to more right
side injuries. Of course, a sample size of three is too small to
make a firm conclusion.
of the places I visited is Duba Plains, an island in the Okavango
Delta of Botswana. The island has a herd of about 600 Cape buffalo,
and a pride of ten lions. Both the buffalo and the lion got there
about a decade ago in a year when crossing channels was possible—since
then both have pretty much been trapped on the island. For
reasons nobody fully understands, the Duba lions only hunt during
daylight—the reverse of the situation in most parts of Africa.
So you go to Duba to see one thing—lions hunting killing buffalo.
I spent five days doing this, and it was quite an experience.
Anybody who has seen a documentary "knows" that lions
hunt cooperatively to bring down prey. Unfortunately, nobody seems
to have told the lions this. Indeed, for many years field biologists
who study lions have realized that cooperative hunting is an illusion.
The naturalist George Shaller figured this out in the late 1960s
with the first quantitative field study. He found that a single lion
has a success rate of 15% on a given hunt—or about one successful
hunt for every seven. Two lions have a success of 29%, which is 3%
LESS successful than if the two lions with 15% individual success
hunted by themselves (32.2%). Three lions get 27%,
or 2% less than two lions. Four, five and six lions get 32% - meaning
that they are (finally) as successful as sending two lions out by
themselves. There is clearly no statistical value to hunting in groups.
More recent studies by Craig Packer and others have looked at higher
order statistics—the variance, or the size of the animal. It
all comes out the same way. If indeed lions hunt in some cooperative
and strategic way, then they get no benefit from it statistically.
So, how come the Discovery Channel says they are cooperative? Partly
it is because these figures are buried in Appendix B of Shaller's
book, or in dense academic papers. Mostly it is because the story
of cooperative strategy in hunting is so endearing to people. Especially
to film editors, which means we are destined to seeing cooperation
in every nature documentary. The cases where the hunting fails due
to lack of cooperation end up on the cutting room floor.
Watching lions hunt, the trends are quite obvious. The primary reason
that groups of lions are no more effective than two by themselves
is that typically only two lions do the actual hunting. They all
make a show of hunting, but in the cases I watched, in several different
prides, there were always a couple females that were the most aggressive
and took the lead. The others hang back for the hard part then rush
up at the end after the worst danger is over. Their primary goal
is to be at the kill early so they can eat, not to actually help.
Field studies have confirmed that lions do not seem to keep track
of this and punish slackers.
Lions can seem quite inept at hunting, because they have no way to
communicate complicated information. The Discovery Channel case happens
when one lion flushes prey in past another for a perfect catch. More
often, what happens is than one lion blows it and scares the game
too early, or flushes it in the opposite direction. After watching
hunt after hunt fail, you soon decide that Iions are not very coordinated.
Indeed their only saving grace is that the buffalo can't communicate
very well either.
are quite impressive animals. They are very brave and will not
hesitate to attack lions when they can. When one buffalo has been
knocked down by lions, the buffalo herd will almost always attempt
a rescue—charging in to drive the lions away. This
succeeds a large fraction of the time—even if the buffalo has
been down for 30 minutes. Of course if the buffalo herd
surrounded the lions when they were sleeping and just methodically
trampled them to death, their whole problem would be over, but there
is no buffalo general to lead them in such an endeavor. Alternatively,
if the buffalo had a bit more skill at rounding up the herd, they'd
never leave some separated which is what the lions look for.
Even a buffalo separated from the herd has reasonable chances. At
one point we saw a lone bull that was trying to get back to the herd,
which was about a half mile away. In between him and the herd were
four lionesses, sacked out asleep. This looked like the perfect opportunity
for a kill, but the buffalo surprised both us and the lions. He crept
up on the sleeping lions, then when he got close he lowered his horns
and charged. The lions awoke, panicked and scattered into the bushes.
The buffalo then trotted victorious back to the pride. It was a perfect
illustration of the adage that the best defense is a good offense.
bringing down buffalo
In order to catch a buffalo a lion must jump on the buffalo's
back, and do to that they need to get past the horns. It's
the same problem that a Spanish matador faces in bullfighting. The
matador has a huge advantage however—his cape distracts the
bull who tries to gore the center of the cape, allowing the matador
to slip by. Lions don't have capes, and as a result they cannot
approach a buffalo from the front—they must jump on
the back from the side or behind. Once on the back, the lion
hangs on for dear life, a bit like a cowboy riding a bull.
The goal is to get the buffalo to stumble. If there is more
than one lion hunting this is the point when they will start
to pile on.
nose biting buffalo
bringing down buffalo
Often the buffalo just shrugs the lions off, and that is
that. However if the buffalo falls down, things get much
more serious. Some cats kill instantly with a bite that dislocates
cervical vertebrae, severing the spinal cord—for example,
cougars in the US. This is not the case for lions, they are
stranglers or suffocators. They either bite the underside
of the neck to collapse the trachea. Or they put their entire
mouth over the prey animal's nose. Either way it is a relatively
slow suffocation that kills the animal. This can take 30
minutes, or even an hour for a buffalo because they can't
get enough pressure on the huge buffalo neck to close it
all the way, or can't get a good seal on the nose. This is
not the quick merciful picture that one sees in nature documentaries.
If the buffalo gets up during that period he or she may get
away with only some minor mauling.
kill with elephants
one of the kills a small herd of elephant came in to investigate.
They clearly were thinking about rescuing the buffalo—they
trumpeted and the herd matriarch ripped a tree of out the ground
to impress the lions. It certainly impressed me! The lions were clearly
concerned, and if they had been attacking an elephant calf they would
have been in trouble. After a tense showdown the elephants decided
it wasn't their fight and walked away.
male on buffalo
Lions don't wait to kill the animal before starting the process
of eating it—as soon as the buffalo stops thrashing, lions
start to eat. This is much harder than it sounds however, because
the hide is very thick. The prime spot to start is always claimed
by the dominant female, or if the male is there, he takes the prime
spot. The prime spot is not what you might thing—it is the
rectum. Believe it or not, the king of beasts starts his dinner by
carefully licking the rectum clean. Since the buffalo defecates while
dying this is a bit messy. The lion then works very hard to gnaw
through the skin and get an incision open.
I was describing this to a friend over lunch in Palo Alto. As I was
describing this the waiter came up behind me to take our order. I
was in the middle of saying "it's very hard to enter
the rectum, but once you do things move much faster", only
to hear the waiter gasp. Whoops. I tried to explain saying "well,
this is about" but with a horrified look he said "I
do NOT want to know what this is about! Some people
are just not interested in natural history, I guess.
eating buffalo 1 hour after kill
Once the carcass is opened the lions settle down to eat. This is
punctuated by each lion growling, hissing and sometimes snapping
at the lions around it. Lions are not polite eaters—they grab
as much as they can for themselves in a pretty direct competition
with the other lions. Usually one of the pride males shows up and
when he does the females give it him a very berth—he can attack
or maim them at any moment. If they want to eat close to him they
approach carefully and try to mollify him with some social greeting
and flirting. Cubs are usually a bit more tolerated
by the male, but even they risk pushing too far. Cubs are quite enthusiastic
eaters and seem to love a carcrass. Some enterprising cubs actually
crawl inside the carcass and eat it from the inside out, leaving
them drenched in blood afterward.
after 24 hours
Within a few hours the carcass has most of the meat gone, and within
a day there is almost nothing left of even a large bull buffalo.
Jackals, vultures and other scavengers move in for the scraps, but
if there is a good sized pride of lions there isn't that much
for them. If hyena are in the area then they will come and eat the
bones, cracking them with specially adapted teeth to get the marrow
and collagen from the bone.
Lion social life is very rich and complicated. In human terms
it is very easy to see them as affectionate, because as social animals
we share the practice of greetings with physical contact. We hug.
They rub noses. These similarities make it easy to understand
what is going on—or perhaps misunderstand because the translation
from lion to human is not 100%.
Lion sex is interesting to watch, but I fear that admission may tell
you more about me than about them. So here is why it is interesting.
many mammals, including humans, have regular estrus cycles, but lions
have a different system. After cubs are weaned the female becomes
interested in sex again and flirts outrageously with the male, wrapping
her tail around his head and other things that are pretty unmistakable,
even to a human observer. The happy couple then starts having sex
- over and over and over again. Lions are stimulated ovulators;
the female does not ovulate until she is stimulated to do so by lots
of sex. As a result lions will mate roughly every 15 to 20 minutes
for two or three days—200 to 300 times in succession. During
that period they are inseparable and will not hunt or eat. They still
need to drink but this is a bit problematic because if the male goes
to drink then another male may sneak in. The regularity of the mating
process is great for a photographer, because lion sex is over very
fast. Although they surely win the prize for the number of repetitions,
each time only takes a minute or so. You have to be all ready to
get a good picture.
Lions are very compelling subjects to watch. This is especially true
in Botswana where you are in open land rovers, often just a few feet
away from them. When a wild lion, its face smeared with blood, is
only a few feet away from you it is hard to keep your eyes of it—just
like it is hard to avoid watching an open flame dance in a campfire.
It's more than just the visual spectacle—there is something
very ancient about our relationship to lions, a fascination with
the dark side of nature. Or perhaps it is that we are both humans
and lions are crown predators. Humans are one of the few creatures
that lions fear, and they are of the few things we fear. Lions are
magnificent animals —they can be cruel, brutal and gory, but
they're also beautiful and fascinating. A bit like
people, I suppose.
NATHAN MYHRVOLD is CEO and managing director of Intellectual Ventures,
a private entrepreneurial firm. Before Intellectual Ventures, Dr.
Myhrvold spent 14 years at Microsoft Corporation. In addition to
working directly for Bill Gates, he founded Microsoft Research
and served as Chief Technology Officer.
Nathan Myhrvold's Edge Bio Page
copyright © 2007 by Nathan Myhrvold. All rights reserved.