The Most Vexing Scientific Debate of Our Time

[Nieztchean Uber-Amoeba]

President Obama's handlers failed to alert their boss to the most clever question he was asked on Reddit in August: "Would you rather fight 100 duck-sized horses or one horse-sized duck?" Staffers with more Reddit savvy could've prepped an answer. Last autumn, New York Times columnist Nicholas Kristof had a quick response. "Definitely one horse-sized duck," he typed. "Then I'd distract it with some cracked corn and, as it gobbled it up, I'd jump on its back and take it for a flight."

How evocative! Imagine the globetrotting opinion-maker soaring o'er the clouds, perched side-saddle. He surveys the earth below and gives his signal. The mallard swoops suddenly down on a Third World capital, his brutal wings pummeling the stunned sex-traffickers until their would be victims flee to safety. An irresistible vision! So much so that I can forgive Kristof, an opinion journalist with a bent for reportage, for failing to factcheck his flight of fancy.

He is hardly alone. Since the Reddit forum, the mainstream media has merely opined about the better choice. Are there no reporters left?

The White House is as awash in speculation:

"In the days following, staffers debated the answer. Most immediately chose the 100 duck-sized horses -- they would be easy to stomp on and were, generally, a reflection of the usual day-to-day conflicts in life. A danger to the shins, but possibly manageable. "Ducks are not exactly teeny-tiny -- so 100 duck-sized horses (as opposed to duckling-sized horses), while smaller than a miniature pony, are still probably clocking in somewhere around ten pounds each," one Obama official argued. "That's a lot to kick/throw/battle."

Who would choose to fight a duck the size of a horse? The beak. The wingspan. The ability to defend and attack in the air, on land, and in the water."

Has conventional wisdom replaced research?

I'd have been tempted to join my colleagues in the press and the people we cover in mere opinion-mongering. But I've been powerfully shaped by a question I conceived earlier in my career: If a shark and a tiger were to fight, how many inches of water would it take for the shark to win?

The item I produced on the subject would've been impossible without shark expert Ralph S. Collier, who graciously answered the question put to him by email. The experience taught me a valuable journalistic lesson: If you send animal researchers outlandish hypothetical questions that touch on their area of expertise, they'll respond generously, especially if inter-species combat is involved*.

John M. Eadie chairs the Department of Wildlife, Fish, and Conservation Biology at the University of California, Davis, where his areas of expertise include avian ecology and waterfowl.

What does he think about Nick Kristof's soaring rhetoric and White House worries about being attacked on air, land, and sea?

"It could not fly," he insists, illustrating his argument by assuming a horse-sized duck weighing 1,000 pounds.

"At 1,000 pounds, the wing-loading (ratio of body weight to wing area) would be immense. The wing-loading of a mallard duck is less than 0.02 lbs/square inch (2.5 pounds over a wing area around 150 square inches). So, scaling up 400 fold (and it is not necessarily linear, but I will assume so for simplicity here), would require a wing area of 60,000 square inches = 416 square feet = 10 ft wide by 40 feet long," he explains. "The wings would have to be immense. Not likely (and indeed this is what limits the size of flying birds, in the absence of jet engines!). So, we don't have to worry about the terror duck attacking from the air. It would be a land lubber." **

The Obama Administration eventually started to ask better questions. "It's just one opponent -- you can focus all your energy, attention, and strength on outsmarting it," the unnamed official told BuzzFeed. "Maybe it tires easily. Hard to know." In fact, it would tire easily:

"With such a huge body, the problem of surface area to body volume comes into play. The terror-ducktyl would have a problem losing heat. Hence, a possible tactic would be to get it running around chasing me and it might overheat, stroke out, and die. Birds have higher body temperatures than mammals in any case (often very close to the 40 degrees Celsius upper lethal limit) so it might not take too much to push the duck over the metabolic cliff. Merits consideration."

And it would be easy to outsmart. "Ducks are dumb. There is a record of some research in which half of a duck's brain was removed surgically ... with no discernible change in its behavior," Eadie explained, though he didn't see that aspect of its biology as an unalloyed advantage. "The flip side, is that in battle, I could literally destroy half the terror-duck's brain and it would have no impact on the battle. Nothing worse than a dumb opponent who doesn't know how to quit."

So did he expect the fight against the oversized duck to be easier?

After all, as nature writer Sy Montgomery, author of Birdology, pithily pointed out in a separate email, "There once WERE horse-sized ducks: they were known as Mihirungs, giant flightless birds who stood up to three meters high and weighed up to half a metric ton. They lived in Australia during the late Tertiary and early Pleistocene. But where are they now? They must have a weakness."

Perhaps so.

But despite its weaknesses, "I fear the duck," Eadie confessed.

Lest you worry that he's just a thoughtlessly embracing the conventional wisdom, as shaped by Alfred Hitchcock's 1963 horror movie The Birds and the chilling scholarly article "Aggressive Behavior and Interspecific Killing by Flying Steamer-Ducks in Argentina," with its talk of "aggression toward a wide variety of species not closely related taxonomically, or similar in appearance or food habits," don't fret: His arguments for the horse-sized duck's strengths are compelling.

As he put it:
"
(1) Birds (ducks) have a far more efficient respiratory system than mammals (one way flow through the lungs and they capture almost all of the oxygen passing through the lungs compared to half that in the lungs of mammals). The duck could easily outlast me.

(2) The wings of a 1,000-pound duck would be threatening armaments. Bird bones are hollow, but incredibly strong, especially the humerus (main wing bone). I have been beaten (literally) when banding Canada Geese and their wings can deliver a wallop that leaves bruises on even the most hardened of field biologists. The Giant Canada Goose (Branta canadensis maxima) is the largest goose in the world and can get up to 20 pounds -- our terror duck would be 50 times the size! One wing thump would be a deathblow.

(3) Birds, when flying, bear their entire body weight on their wings. And, when migrating, they do this for 24-36 hours at a time. So, they are suspending their entire body weight by their "arms" held straight-out from their side. It is equivalent to a human gymnast holding the iron cross position for 24 hours. And lifting their body up and down repeatedly. You want to fight something that can do that?

(4) Even our ex-governor in California would envy the chest muscles of a bird. Their wings are powered by huge breast muscles (the pectorals major and pectorals minor) that lift and lower the wing and the bird's weight. These muscles comprise up to 30 percent of the birds body weight. So, our terror duck has 300 pound 'pecs. Nope, not wanting to face that.

(5) Waterfowl are omnivores, horses are herbivores. The duck could eat me, the horses would not.

(6) Birds have gizzards, known for their crushing ability. A shrike can digest a mouse in a few hours. Turkeys can crunch 24 walnuts in the shell in less than 4 hours and grind surgical lancets to grit in less than 16 hours. Aside from what the terror-duck's gizzard would do to me if it ate me, it could easily chomp down and grind to dust any weapon I might have.

(7) The bill of a duck is adapted for picking and sieving. It has ridges called lamella - regular teeth like edges on its mandibles. Nothing to really worry about for a regular-sized duck. But scaled up 400 fold (2.5 pounds to 1000), those 0.02 inch long lamella would be 8 inch long crusher blades with 50-70 of these arranged along the edge. Hmmm. Not wanting to faces that, thanks.

(8) Waterfowl are among the oldest existing group of birds. And we know quite well, now, that birds are actually dinosaurs (I kid you not). Their ancestry --- theropod (maniraptoran) dinosaurs. They are relatives, and most closely aligned, with the group that includes tyrannosaurs and velociraptors. They have serious attitude and it comes with the family history.
Eadie is almost dismissive of the duck-sized horses. "

Granting that they'd be fast and capable of fighting in a herd, he points out that "horses are edgy and easily spooked. Move toward one, especially quickly and unexpectedly, and they run away (if you have never tried to saddle even a tame horse, try it). And if they were scaled down to the size of a duck, even their most potent weapon (kicking with their hooves or biting) would not be lethal and would likely deliver little more than bruised or nibbled shins." Of courses, the horses could more easily run away, but it turns out they'd also be easier to best in a war of attrition:

"At their high metabolic rate, and the increased surface area to volume ratio, the dorses would be challenged to keep up a fast or active lifestyle and find enough food, especially if they remained herbivorous. Horses spend a large part of their time eating even at their current size, given the long processing time required for digesting vegetation. At the size of a duck (with much more surface area to volume, such that they would rapidly lose metabolic heat), they would need much more food relative to their body mass. They would eat all day. So it would be easy to sneak up on them. Or starve them to death. Or woo them over with apples and sugar cubes. And if it got down and dirty, given the relatively frail ribs and femurs of modern horses (work horses excepted), I suspect that many of the dorses cold be dispatched with a swift kick."

Finally, just as there were giant birds that went extinct, Eadie points out, "there were indeed small horses (Eohippus, about the size of a small dog). They went extinct. That says something."
****
So wait just a minute, you might be thinking. If Eadie and a majority of people who've pondered this question say that the 100 duck-sized horses would be the easier biological opponent, why am I so sure that President Obama would fight the horse-sized duck?

Come now.

Prudence and biological consequences are low on the list of factors that dictate which wars of choice get waged, as so many maimed veterans of the Iraq War can attest. Political reality matters more.

Eadie understands as much. After engaging his graduate students in conversation, he came to realize that it would be politically disastrous for Obama to fight the duck-sized horses. Think about it. In America, the duck lobby is composed of duck hunters. The horse lobby is made up of horse lovers who succeeded in stopping Californians from buying horse meat. The young women voters essential to the Democratic coalition are far more sympathetic to veritable ponies than a giant, rape-obsessed mallard. Shooting the duck would be perfectly legal under existing law, or would at worst result in a citation for hunting without a license.

But killing the duck-sized horses?

"If Obama killed just one of the hundred 'dorses', he would be subject to legal action and huge fines under existing federal law (e.g. The Wild Free-Roaming Horses and Burros Act of 1971, the animal welfare act and, based on a recent case, even the National Environmental Policy Act)," Eadie points out. "There is no sport horsery! The legal implications would have him tied up in court, bankrupt or in prison faster than you can say Secretariat."

It's easy to anticipate the coalition that would form against him. Still upset about being dinged for putting Seamus on the roof and urged by his Rafalca-loving wife to intercede, Mitt Romney would lead the charge to draw up impeachment papers. Congressional Republicans would surely be amenable to cooperating.

Even barring that scenario, the politics are clear: You fight the giant duck. So what about the execution?

That's actually the clincher.

A moment's reflection is enough to understand that Obama would "fight" his inter-species foe the same way he "fights" militants. It would probably be hard to pummel a horse-sized duck to death or to slay it with a sword, but the commander-in-chief's weapon of choice is a Predator drone equipped with a Hellfire missile, operated under secret legal authority. Behind their computer screens in the Nevada desert, would it be easier for the drone pilots to kill the horse-sized duck, or the whole herd of duck-sized horses? The little equines would scatter, despite the preparatory steps even now being taken to prepare them for the duress of war:


In fact, it isn't clear that the American people would buy the notion of little horses being legitimate targets in the War on Terror. But the giant duck? Sure, its presence on American soil might complicate things. Even neoconservatives are made uneasy by the prospect of drones in American airspace. But that's where the real genius of choosing the horse-sized duck is revealed.

You've heard of avian flu? Yeah: bioweapon. Obama could plausibly claim that there are more WMDs in that monster duck than were ever found in Iraq, and he's surrounded himself with people who voted for that war in 2002. The whole Washington establishment and much of the nation would rally behind Obama against the duck. Go back to the beginning of this story and you'll see that even an unprompted Eadie, a dispassionate man of science, reflexively started referring to the foe as "a terror-duck." Given America's post-9/11 deference to POTUS in matters of terrorism, Obama would obviously choose "the terror duck" as his enemy. Its ducklings would be lucky to survive.
__
*I've had less luck getting answers from experts about ethics in centaur medicine, though I don't know whether that is because no blood sport is involved or because centaurs are mythical.

**Note to James Fallows: "Blind into Duckdad" for the April cover? Think about it.

[Darmalus]

You've baffled me. What is this rambling nonsense supposed to be about?

[Dr. Trainwreck]

Sweet gods of the Babylonian pantheon. None of these guys had anything better to do?

What the hell am I talking about? This is the Internet. Of course they had nothing better to do.

[Sea Skimmer]

Hmm, I thought this was a serious post and ignored it until now, so sad I did.

I think you'd have to be mad to want to fight a horse sized duck, it would easily kill you even if you had some basic melee weapons. Killing a hundred tiny horses might be annoying, but you'd be able to exploit all kinds of cover and obstructions against them even if unarmed, and they have no direct means of killing or easily crippling you in one blow, unlike a thousand pound duck biting at your face and neck. You'd only be at risk from the horses if you screwed up big time, while the duck is death if you make any mistake. Either one could well exhaust you in a fight though. Also helps that horses themselves are really easy to injure. Just knocking one over could cripple it with broken legs.

[Hawkwings]

I believe that a horse-sized duck would probably face all sorts of strength scaling issues - the same issue that would face a horse-sized ant, for example. Assuming a rough scaling of a duck's body plus head to a horse's body plus head, assuming a large mallard duck (26 inches in length - source), assuming a horse of length 8 feet (source: looking at a picture of a horse, plus wikipedia) the duck would increase in linear dimension roughly 4 times. Meaning a 4x4x4=64-fold increase in mass.

A duck must stand on land on its two legs. Each leg has a cross section of (generously) 1cm^2 (source) so scaled up that would be 16cm^2 each. But, because of size/mass scaling, each leg would have to take 4 times the weight that it was designed for. This is feasible, but likely any serious trauma including falling would break these legs.

Plus there's the muscle to think about. A horse-sized duck would have muscles designed to pull around things that weigh 4 times less per muscle cross section.

I believe a thought experiment is in order: Imagine you are suddenly 4 times heavier, or alternatively 4 times weaker than you currently are. Can you defeat a normal non-crippled child in single combat?

[Hamstray]

100 duck sized horses seem less threatening than 100 duck sized ducks.

Faced such a question I wouldn't be sure it wasn't some kind of metaphor for internal or external affairs policies.

[Dr. Trainwreck]

100 duck sized horses seem less threatening than 100 duck sized ducks.

I'd hazard a horse's shape and structure to be ill suited for the size of a duck.

[LaCroix]

100 duck sized horses seem less threatening than 100 duck sized ducks.

I'd hazard a horse's shape and structure to be ill suited for the size of a duck.

A horse has legs with an average diameter of 3-4 inches for half its length. This would mean that it would end up with legs thinner than 1 inch - and any damage to any leg would be crippling. Combined with the fact it's now only 15-20 lbs total weight.

Something like that!


Plus, it has to turn around to effectively attack you - horses won't bite anything bigger than them, and rearing doesn't really hurt you if it's that small.
They might rear and try to hit you in the groin, but that is usually not done outside of rank fights - defense is done by kicking out.

Anyway - take a big stick and whirl it around you with force, and you'll be standing on a hill of dead and dying Equnculi pretty fast..

[Ziggy Stardust]

Why do the last couple of paragraphs of this article descend into gibberish? I mean, I know the whole thing is a joke, but I feel like I am observing the author's descent into madness, here.

[Dr. Trainwreck]

Ziggy, the article did not wait until the last two paragraphs to go batshit.

[Irbis]

They might rear and try to hit you in the groin, but that is usually not done outside of rank fights - defense is done by kicking out.

Anyway - take a big stick and whirl it around you with force, and you'll be standing on a hill of dead and dying Equnculi pretty fast..

What. Either no one here saw duck, or they are larger elsewhere. Dogs? Duck is not a goose, duck-sized horse would be smaller than a cat. See picture. Simple high leather shoes would make you totally immune to its attacks, you would be killing them (eventually) by simply marching through the herd, any contact with boot easily snapping legs or necks. Groin kick? They would be lucky to hit your knees.

Now, horse size duck might not be able to fly, or even move that well, but duck foot are good in distributing weight on the ground, and as noted, any wing attack would be at neck height, snapping it instantly had it connect. Hell, you don't need wings or beak blades, first instinctive reaction would be to peck, and a bill that big to chest or neck would again be one hit kill. Add to that armoured skull, not very vulnerable brain, heart protected by 300 kg of muscle and killing it in open combat with anything smaller than high-powered sniper rifle is highly unlikely

[Korvan]

I wouldn't want to fight either. Ducks are nasty little buggers. I've seen one just about murder another over a crust of bread. Bit the other duck on the neck and just wouldn't let go. I've been bit on the hand and pecked on the legs a few times when I ran out of bread. I couldn't carry enough bread to ward off a giant duck.

I've also been bitten by horses and had my foot stepped on more than once. And these were friendly horses just playing around. 100 small horses all rolling their crazy horse eyes at me? No thanks!

[PainRack]

I say we take off and nuke the entire site from orbit, just to be sure

[Flagg]

How many giggatonnes can the horse sized duck wield? And if the duck sized horses were a spherical mass of iron...

[Jub]

How many biggatonnes of energy would bags of rice cause the horse sized duck to release and would George Lucas go back latter and add rings to the explosion for the special edition?

[Dominarch's Hope]

The big duck. 100 duck sized anythings is just way too annoying to deal with.

[PainRack]

How many biggatonnes of energy would bags of rice cause the horse sized duck to release and would George Lucas go back latter and add rings to the explosion for the special edition?

The Strategic Defense Initiative vehemently disagrees with the Disciples of Wong conclusions ! He can lift 150 pound barbells, how could a horse sized duck be effective against that!

[Lancer]

Well, clearly the precognative abilities of the duck have no limit, so you're screwed even if you can move faster than the duck could react...

[Algebraist]

As pointed out already something similar to a horse sized duck in effect already existed - it was a dinosaur. However to exist the massive duck cannot be an exact scale up, in particular the creature needs relatively thicker bones to combat gravity (weight scaling as a "cube" but bones cross section scales as a "square"). It certainly couldn't fly - the same scaling issue applying to wings and muscle! It would be a formidable opponent though with both its beak and wings (although flightless). Even a swan is pretty dangerous. On the other hand I cant think of any small pure herbivore of a similar genus to horses that I'd be scared of. They certainly wouldnt have any motivation to attack unless to protect young. If they did you could take out the first one and I'm sure they would flee!

[Channel72]

The closest thing to a horse-sized duck would be any of the larger Dromaeosauridae/raptors like Utahraptor, except those animals obviously evolved for moving about at that scale, and had muscular legs and long tails which provided balance, unlike a duck. Plus they were extremely fast, whereas the speed of a horse-sized duck is extremely questionable, considering their relatively small, webbed-feet are set pretty far back on their body. Duck legs obviously aren't evolved to move around fast on land, let alone carry that sort of weight. You'd probably be able to just out-run the duck, whereas you obviously couldn't outrun something like Deinonychus or Utahraptor.

[Enigma]

One horse sized duck versus me with a rifle and bayonet. Shoot it from a distance and then close up for the kill. Take a picture and then go home. A hundred duck sized horses are just too cute and assuming they are docile, I'd take them home and sell them off for $$$ cash money. Boom, baby!! lol

[Channel72]

Incidentally, there's also an extinct animal which is pretty close to a duck-sized horse: the Hyracotherium - albeit, it's actually a bit larger than your average duck. It's more the size of a goose, swan or small dog. Still, it's pretty close to a duck-sized horse. Needless to say, it's really not that threatening, and I doubt 100 of them would be any more threatening, seeing as how they're not intelligent enough to conduct any kind of coordinated assault. Obviously, a giant horse-sized duck, if we hand-wave away the scaling problems, would be much more dangerous.