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Research Day: How Much Does An Adult, Male, African Elephant Weight?

It's not often that I shout "holy shit!" while listening to NPR alone in my car, but that's what I did a few weeks along when All Things Considered aired the story of Osama the Hippopotamus. "He's believed to be a male," the reporter said of the hippo who has been terrorizing villagers on the Congo River, "though no one has really gotten a good look at him. A full-grown male hippopotamus can weigh up to 8,000 pounds ..."

What?! That can't be right, thought I -- he must have meant eight hundred pounds. What an embarrassing gaff to broadcast on national radio. Later he said that hippos are considered to be "the most lethal animal in Africa, killing more people each year than lions, crocodiles, and elephants." That struck me as almost equally improbable. I thought hippos were cuddly. And only attacked marbles.

But I figured I'd doublecheck before sending an email to NPR starting "Dear dumbasses," and did so as soon as I got home. "How was work?" The Queen asked as I walked in the door; "No time for chit-chat!" I exclaimed, "I gotta go look up hippos in Wikipedia!"

And whatta'ya know? "Hippos average 3.5 metres (11 ft) long, 1.5 metres (5 ft) tall at the shoulder, and weigh from 1,500 kg to 3,200 kg (3,300 to 7,000 lb) ..."

I sat there at my computer for a moment, trying to process this information. Then it occurred to me that the elephant, world's largest land animal, must somehow be even larger.

I braced myself and surfed over the the Wikipedia page for Loxodonta africana. "The Savanna Elephant stands on average 13 feet (4 meters) at the shoulder," it said. "And weighs approximately 15,400 pounds (7,000 kilograms) ...." Subsequent research revealed that Wikipedia's estimate is on the high end of the spectrum -- The Columbia Encyclopedia has them down for an average weight of seven tons (14,000 lbs.); Britannica pegs their maximum weight at 16,500 lb; Encarta says they "weigh up to 7,000 kg (15,400 lb)." My guess is the person who did the Wikipedia entry came across that "up to 7,000 kg" figure, mistaken cited 15,400 lb as their average weight, and that 14,000 lbs. is more accurate.

But still: 14,000 lbs! That's just insane. And I don't even understand the physics of it. If you hollowed out a male, African elephant, I can't imagine you could fit seventy 200-pound human beings inside the skin, even if you ground those people into slurry and poured 'em in through a funnel (free Science Fair project idea right there, if any kid are reading this).

Now, I'm notoriously bad at estimating things: population of cities, miles of a road, number of beers it takes to get myself drunk, etc. But even so, I had a hunch that just about everyone would get this one wrong when asked. So last week I slapped together an poll to see what people say when asked the average weight of a male, African elephant. When I'd amassed a little over 2000 votes, I made some graphs, thereby transmogrifying this exceptionally haphazard experiment into SCIENCE!

And how did you all fare? Oh my goodness, not well at all I'm afraid.

Average guess: 4964.60 lbs. -- i.e., close to a third of the actual weight. It probably would have been a lot lower, but there were a few 50,000 lbs. and one 65,000 guesses. The top five most common guesses: 2,000 lbs (1/7 of the actual weight), 4,000 lbs., 3,000 lbs, 5,000 lbs, and 2,500 lbs. Eighty-one people guessed 12,000 (it was the eighth most common guess), eleven guessed 14,000, and another eleven guessed 15,000.

I'd always heard that, on questions of estimation, you could expect to see a bell-shaped curve around the correct response. Obviously that wasn't the case here. I've convinced that it's because the weight of an elephant is so incredible -- by which I mean, it honestly strains credibility. Two thousand pound is a good guess for weight of "animal that is extremely large and yet still real"; 14,000 pounds is a good guess for the weight of, like, "dragon," or something equally as chimeric.

By the way, the largest elephant ever recorded weighed 12,000 kilograms, or nearly 26,500 lbs. I'm glad they didn't mention that on NPR, or I probably would have driven off the freakin' road.

Thanks to Squant and M-J for fancy graph assistance.

Posted on March 06, 2006 to Research Day


"If you hollowed out a Male, African, Elephant, I can't imagine you could fit seven hundred 200-pound human beings inside the skin"

Uh... 200 * 700 = 140,000 -- that's 10 elephants. Still 70 people per elephant are a lot as well.

Posted by: michael on March 6, 2006 10:17 PM

I think the reason for the curvature of the guess-graph, is that most of us did what we do every day, pull stuff out our asses. I had no clue what the weight of an elephant was, and guessed a bit on the cautious side.

It would be interesting to find out what people think the Blue Whale weights. I have no clue about their size, except they are the biggest mammals alive, and are on a scale I cannot even fathom.

Posted by: Jonas Rabbe on March 7, 2006 12:41 AM

I found out that we weren't pulling stuff out of our collective behinds, we were making SWAG: Scientific Wild-Assed Guess[es]

Posted by: Jonas Rabbe on March 7, 2006 2:01 AM

I overshot it...14000. I dunno. Maybe I'm kinda immune to the shockingness of science facts. I went through a science/zoology dork phase.

Posted by: rob glover on March 7, 2006 4:33 AM

Really, I think we're looking at closer to 30,000 lbs as an average for the North European Land Dragon.

Flying varieties often weigh less due to their aerodynamic properties.

Few accurate weights have been taken from the fire breathing variety as the gasses they generate to create their flame are lighter than air and add bouyancy.

All these measurements are made more difficult by the fact that it is impossible to do any measurements on dead specimens. The dragon's acidic blood disolving the body shortly after death. Scientists are as yet unsure what internal chemical reaction stops upon death, yet without such internal chemistry the dragon would surely dissolve away upon hatching.

Won't you help us preserve the habitat of the magnificent creatures?

Posted by: Kevin on March 7, 2006 6:02 AM

for a more accurate guess that excludes the high-end outliers, you should take the median average, rather than the mean average. still, i guessed i think like 3000, thinking that since it must be bigger than i thought (~1500) or else you wouldn't write about it, i had better WAY overshoot my initial guess. i was still so ridiculously low.

Posted by: zach. on March 7, 2006 7:10 AM

I love your blog!

Posted by: Anita on March 7, 2006 7:42 AM

Muscle is a lot more dense than fat, so if you're visualizing seventy 200 pound people, you should be thinking of people like Arnold Schwarzenegger and not Tom Arnold. I'm guessing most of that elephant weight is bone, muscle and lean tissue mass, not fat, so it will be a lot more compact than fat.

Posted by: PastaQueen on March 7, 2006 7:55 AM

Instead of guessing the weight I really wanted to ask the question "African or European?". Unfortunatly you had already specified African, so I decided to do what you asked instead. I'm glad I did, because my guess of 1,400 lbs. was WAY LOW!

Posted by: bred on March 7, 2006 7:58 AM

That explains why "crushing by elephant" was actually a common form of execution in India and SE Asia...really! Look it up in Wikipedia!

Posted by: SMurph on March 7, 2006 8:58 AM

I'm pretty sure that a cow weights upwards of a ton (we're talking about a real actual cow, not some sort of baby, pet-it-at-the-fair cow). All things considered, that makes the elephant more believable. I still would have guessed like 10,000 lbs... man... that's a lot of tons of elephant.

Oh... you'd be surprised how many people you can fit in one, as long as you really grind the slurry pretty well.

Posted by: Ari on March 7, 2006 9:34 AM

How many calories in one of those things? I had one for lunch on Monday, and I'm still not hungry.

Posted by: Rob Cockerham on March 7, 2006 10:23 AM

Oh, man, Bred stole my line.

My kid was going to make a beer bong for next year's science fair, but now we're going to have to go with elephant skin human slurry.

Posted by: laura on March 7, 2006 10:47 AM

A dragon (ancient, of course) would of course weigh 819,200 pounds, as it is four size categories larger than a human. Read your Monster Manual, people. You will also learn that all cats weigh just over 3 pounds. Whose fantasy is that?

Posted by: Rob on March 7, 2006 11:13 AM

Back when Mad Cow and Foot-and-Mouth Disease were in the news at the same time, someone was discussing the problem of disposing of herds of cattle to control the infestation (or infection, or whatever) and I was told that one could reasonably use 1000 pounds as the average cow weight, 2/ton. So having been told that, I'm amazed that so many people guessed that enormous elephants would weigh 1000 pounds and also skeptical of the above commenter that they weigh a ton. Bulls, maybe.

At any rate, wikipedia is agnostic about the weight of cows. Google results indicate that cow weights vary from 700 to 1500 pounds depending on breed and whether or not she's milking.

Posted by: LAN3 on March 7, 2006 11:56 AM

I guessed 5000 kilograms

Posted by: :p on March 7, 2006 11:57 AM

You wouldn't expect this to be a bell shaped distribution, because there is a lower limit to what people can guess (0, and, in fact no one would guess that), but no upper limit. This is more like a chi-squared distibution, see http://www-micro.msb.le.ac.uk/1010/1010pics/chi.gif

If you want it to look more bell shaped, make the X axis a log axis. I know, I'm geeking out a little heavily. Sorry.

Posted by: swamper on March 7, 2006 12:20 PM

I knew that a deent-sized horse weighed about 1,000 pounds.... yet still only guessed that an elephant is four times that weight.

Posted by: tori on March 7, 2006 12:32 PM

I am still almost completely incredulous. I guessed 800 lbs, so this is just all kinds of crazy to me. It has led me on a massive (snicker) size and weight find-out-a-thon.

Your average cow is not quite a ton, more like 1,000 to 1,400 pounds. BUT STILL!

& the blue whale? The blue whale can weigh upwards of 300,000 pounds. 150 tons. It does sounds like most are in the 125 ton range, though. They eat over 7,000 pounds of krill every day.

I'm going to go have a big mac & a shake.

Posted by: Liz on March 7, 2006 1:38 PM

Shoot. Them elephants are HEAVY mofos.

Posted by: Vaguely Urban on March 7, 2006 7:08 PM

Check out _Why Elephants Have Big Ears_. There's a whole fascinating physics around mass, size, structural integrity, heat retension, etc, for animals at the large or small end of the spectrum.

Posted by: Al Tabor on March 7, 2006 8:23 PM

Ah - the maths thing comes to the fore again here. Mass is linked to volume, right? And volume is height x width x depth. So if an elephant is twice as big as a car in every dimension, it's 2x2x2(=8) times the volume. So in terms of volume, these things are BIIIG.

Once you've got that, I guess you think about what elephants are made of. I mean, they eat a lot (a LOT) of plants every day, so that weighs quite a bit (because plants are not very nutritious). And then the bones must be pretty solid just to support the thing. And the muscle.
And have you ever wondered how heavy those pyjamas that they wear must be? I mean, if their skin was the same size as the body, that'd shed a few pounds!

As for hippos, they're just lazy elephants. And if I was having a mudbath and someone came and poked me, I'd eat them!

Posted by: Nick on March 8, 2006 6:28 AM

For the science fair pouring of the human slurry into the hollowed-out elephant, I have considered various methods and I think it seems most appropriate to elevate the trunk of the hollow elephant, and pour it in through an industrial-sized funnel. Alternatively, one could use a pressurized tank distribution system for the slurry-to-elephant operation.

Posted by: freezio on March 8, 2006 7:05 AM

I don't think it's so incredible. The thing to remember is that weight is a 3rd degree function of size: if something is twice as large, it'll be twice as long, twice as high, and twice as thick, thus its weight will be 8 times as much. It rises fast, that way.

It still feels strange though. For example, a litre of water weights 1 kg, it is as large as a cube of 10cm in all directions. Take 1g, which seems negligible by contrast, is still 1cm in every direction... which still looks biggish. A 1mm cube weights 1 mg... and is still visible, about the size of a grain of sand.

And a cube of 1 m in all directions, weighs a tonne.

Posted by: Bart on March 8, 2006 7:59 AM

Ok, here's another weight thing to think about. My daughter was doing a report on leatherback turtles. A typical one runs 500 to 1500 pound. Stay with me here. In captivity, they will eat twice their body weight in jellfish (and related soft-bodied creatures) each day! So tell me, how much more do they eat in the wild, where they're battling ocean currents? And where does a body come upon 3000 pounds of jellyfish each day?!?

Oh, additional 2nd grade report tidbit: after hatching, male leatherback turtles are not known to return to land... ever!

Posted by: The Fishmonger on March 8, 2006 9:42 AM

I guessed 5000 pounds, based on the cow-mass thing mentioned by LAN3 above and a wild guess at the math discussed by Nick. Where I went wrong is that African elephants are much larger in comparison to cows than I had thought. Perhaps I was picturing the Indian elephant? No idea.

Anyway, I think michael's point that it's only 70 big people ground up to fill the elephant is totally within the realm of reason. In fact, if I had approached the problem by thinking "how many people could I squeeze into an elephant's skin?" I might've been closer to the mark.

Posted by: Deadlytoque on March 8, 2006 9:45 AM

I can't thank you enough for that post. It's everything I've ever wanted to say when resorting to the phrase 'That's crazy!'

Posted by: yb on March 8, 2006 11:29 AM

You guys really have to get with the 21st Century and stop using feet and pounds...

Posted by: David on March 8, 2006 4:01 PM

I figure they're twice as tall, 4 times as wide, and about 10 times as thick as a person... so 150 lbs x 80 = 12k lbs.

Posted by: Ernie on March 8, 2006 6:45 PM

suddenly i'm feeling a lot better about gaining almost 40 pounds this pregnancy.

other random elephant-'n-pregnancy fact: elephants also gestate about 22 months. suddenly 10 months doesn't seem so bad.

Posted by: carmie on March 8, 2006 8:39 PM

1) You have a heckuvalot of readers.

I'd always heard that, on questions of estimation, you could expect to see a bell-shaped curve around the correct response

2) The version I heard pertaining to this is that if you just post the graph, without the correct answer, then iterate the process of asking for answers twice more, then you get a bell-shaped curve around the correct response. Not sure if I'm any more correct than you, though!

Posted by: Chris M. Dickson on March 9, 2006 5:26 AM

The hippo, to draw from a minor point in the intro of the piece, really does kick a lot of butt. It has no natural predators, and even lions are afraid of it.

The zulu have a song/chant that roughly translates to "He is a lion, he is a lion. Yes, he is better than a lion. He is a hippopotamus"

Posted by: Dan on March 9, 2006 6:50 AM

Hippos are pretty mean. While more deaths are attributed to hippos than the other animals, that statistic is a little skewed as when a hippo attacks a boat and people fall in and drown, the hippo gets a chalk mark on its board. The solo male cape buffalo is really the most dangerous animal to deal with.

You'd think they're just lazy fat bastards by looking at them, but they're really quite fast. I was attacked by one in Zimbabwe and didn't know what happened until it was over.

Posted by: Sam Jackson on March 9, 2006 1:58 PM

You think elephants are big?

A blue whale's TONGUE weighs as much as an elephant. No foolin'.

I can't even picture that.

Posted by: Grant on March 9, 2006 8:20 PM

Missed your elephant weight survey. Not sure what I'd have guessed but I know a pig can weigh nearly 2,000 lbs. (990 kgs) so I would've guessed a good bit higher than that. At that size pigs look like a compact truck.... Unrelated African animal question; Ever since I saw the movie THE GODS MUST BE CRAZY 20+ years ago I've always wondered if it could be true that rhinos really will stomp out campfires? Anybody know? (not that I'm going to believe what I read on the internet) Large Louie

Posted by: Anonymous on March 9, 2006 9:35 PM

I guessed 14,000 pounds in the survey largely because I had recently read Actual Size out loud to a bunch of kids and it mentions that an elephant (I forget which type) weighs 14,000 pounds. Otherwise I'd have had no idea. Also, I probably wouldn't have remembered the weight if I hadn't translated it as "100 adults", amended to, "fine, 50 adults the size of your dad").

Posted by: Anonymous on March 10, 2006 6:50 PM

If that surprised you, check out planet earth -
6,000,000,000,000,000,000,000 Tons.
Now THAT is what I call heavy

Posted by: Einstein on March 11, 2006 8:51 AM

Oh, by the way, the Hippopotamus is the second biggest killer in africa, the first is the moskito!

Posted by: Einstein2 on March 11, 2006 8:56 AM

The size of a whale is pretty much unimaginable for most people. I mean: We all have seen elephants and we cant guess the weight correct. But a whale?
My wife an i onnce planned to see the whale sharks (the biggest living fish) and by describition it was clear that they are bigger then the one-room-apartment we shared back then! Incredible!
(Unfortuneltly the visit didnt push through)

Posted by: Peer Sylvester on March 11, 2006 9:22 AM

An average horse weighs 1,000 to 1,200 pounds, so obviously an elephant is going to be much heavier.

Posted by: Tandy on March 12, 2006 3:36 PM

that picture of the sp called yeti seems to be really fake. your making it seem like they are not real or something. If you want people to beleave that they are real then you shouldnt put a fake picture in there. Or on your site. and I wanted to know if you could out what yeti's eat on your site. Im doing research about them And thats the only thing that I could not find out. So when you get the chanc e please add this to your site. bye thanks alot. Mandy

Posted by: Mandy on March 23, 2006 4:20 AM