# What evolutionary pressures would lead to being skilled at counting and basic arithmetic?

Let's say we came across a new species of moderately intelligent birds. Like Alex the parrot, these birds are able to learn a few words and simple concepts. But once we teach these birds the words for different numbers, we are astounded by the fact that...

...these birds can already count (to at least 100) and do simple arithmetic.

What evolutionary pressures could have possibly led to this scenario?

• Corvids are known to be able to count and do simple arithmetic, such as, for example, four men went into the hut, three came out, there must be one still in there. As for why this is advantageous, consider the difference between the crow who can keep track of the four hunters seen to approach and the crow who cannot; or between the raven who can keep track of its five fledlings and the one who cannot. Being able to count and do simple arithmetic is always an advantage for a highly mobile and versatile animal. Apr 27, 2017 at 0:12
• @AlexP, I was thinking of counting to higher numbers -- I'll edit the question to reflect that.
– Joe
Apr 27, 2017 at 0:14
• simple arihmetics help with surviving the next winter: if i need 500 dried fish and 15 crates of potatoes to make it through the winter, and i am able to count, then i can better prepare for winter, helping me to survive, and subsequently procreate (more) Apr 27, 2017 at 13:00
• @Burki - surely nature would then favour the animal who couldn't count and constantly over-estimates, then? The squirrel who buries 1000 nuts but only needs 300 is going to do rather better than the one who stops when he's put 350 into the ground. Apr 27, 2017 at 13:15
• @SteveTaylor but the squirrel that hoarded less than 300 nuts starves. Apr 27, 2017 at 13:22

## 4 Answers

There's a very simple answer to this one: Mimicry of flora/fauna with number-specific differences.

Consider the 13-spot ladybird:

Next, consider the 16-spot ladybird spider:

In an environment where predator or prey is a mimic with a subtly different number of spots or other distinctive feature, counting can become increasingly important. Or else if variants with a certain number of spots were poisonous, evolution would select for the birds able to distinguish one from the other.

Of course you can create subtler differences in your prey species - perhaps the edible ones all have multiples of seven spots which are added every time the creature moults, almost like the rings of a tree. In a similar vein it wouldn't even have to be about prey - if there was a deadly plant or another threat which was number-specific, such a trait would probably select relatively quickly.

• This seems plausible, yeah. Apr 27, 2017 at 15:11
• I would definitely say this could lead to rapid counting. I think by itself it wouldn't lend itself to arithmetic, but I feel that there is some tweak with the premise that could lead to advance arithmetic, Maybe if different species spots tend to come in patterns of 3 vs 4 vs 5 in different species so a rapid ability to distinguish rather the total number of spots is a divisible of 3/4/5 to identify which species may be doing the mimicry. If I see 30 spots It could be a prey species that tends towards 3 spot pattern or 5 spot patterns, but not a predator with 4 spot patterns? Apr 27, 2017 at 21:22

Social behavior, we know for instance that social primates will not accept extremely uneven sharing. Anything more than about a 3/5th diffrence is rejected. Being able to tell how many of your social group are present can be equally important. Especially if comparing your group to another group. math becomes especially important one you have the ability to communicate. Turn left at the many trees is not as good as turn left at the three trees. More basic keeping track of predators or dangers could be useful, how many wolves went into the cave vs how many came out can be important. The bbc has nice little article about its uses among animals http://www.bbc.com/earth/story/20150826-the-animals-that-can-count

• Many herd animals seem to be able to count, as well as our domesticated herd keepers. Although I would agree with most of what that article sais, I would argue that there are a couple of exceptions in the dog family that I'd say should be able to count. For example the Old English Sheepdog. But I don't have evidence for that, just personal experience in the way that they seem to always know when someone is missing, even if there are larger numbers in their "herd" (including people) Apr 27, 2017 at 8:47
• @DoomedMind, sounds like our border collie. I swear she is smarter than me. Apr 27, 2017 at 14:03
• Social interaction has generally been the driver for advanced intellect throughout evolution. Thus this seems the most likely explanation I've seen so far. however, my one issue is that social interaction is too good at developing intellect. By the time a species has developed to the level you mentioned their a good ways towards full human sapience. At this point I imagine they would be driven to a more general intellect, reasoning skills and learning that can be adapted to many uses, rather then specifically to math. So just normal humans. Apr 27, 2017 at 21:18
• @dsollen I think you are overthinking social here,even something as simple as herding and pack hunting would greatly encourage being able to estimate relative group size which requires some instinct for numbers. Is our pack bigger or smaller than that pack would be vital.
– John
Apr 27, 2017 at 21:21
• How about using proper capital letters on your sentences? Apr 27, 2017 at 23:14

I recall a demonstration of a dog that could count up to n, where the trainer threw a bunch of practice dead animal dummies into the tall grass some distance away and gave the command to fetch. Each time one was returned, he repeated the command.

If the number of objects that were thrown was ≤n, then when the next (excess) command was given, the dog would walk around the seat and sit, indicating "I'm done with that, ready for next command" without going out and doing any searching. If the number of items was larger than the dog could count, then he would head out to search for more, even though there were none present.

Being able to remember how many prey animals are hidden saves the futile work and also increases confidence that you got them all. How much extra time would you spend working an area just to be sure? It also means they can calibrate their idea of how well the prey hides, rather than supposing a certain amount of work is good enough. This saves work in general, when deciding if an area is finished.

So, imagine an evolutionary arms race where prey animals can hide, burrow, or whatnot, when they see the predator coming. How much work they spend digging deeper or hiding better can vary depending on strategy, if they are making the predator work harder as well and waste work and waste time. Knowing how many are hiding will cut out that game and give them an advantage.

Perhaps the mental capacity to count to n increased a bit at a time, until it somehow reached a general point where instead of 7 or 9 they could handle on the order of hundreds, because the mechanism had an increment/decrement feature and internal state.

• In addition to what JDługosz has said, it appear that some birds can actually count. In cormorant fishing, where traditionally the cormorant was allowed to eat one fish of every eight they caught, the birds stubbornly refused to continue fishing until they were allowed to eat. Wikipedia Apr 27, 2017 at 8:30
• I'm not sure this is sufficient to drive counting as an evolutionary factor. I'd think it would push predators to adapt a lurking style hunt, but not more. Apr 27, 2017 at 8:38
• The example you mentioned sounds just as likely to be a "Clever Hans" effect as actual counting. As to the example. I tend to agree with Doomed. Why would a predator know the number of prey that were in an area ahead of time? even if they did why would they care. generally one or two prey is enough to make a meal, any prey more then that in an area a predator doesn't care about because there is no point in catching more food then they can eat. Thus there is little reason to learn to 'count' higher then 2 and then walk away with a fully belly Apr 27, 2017 at 21:14
• A “clever” dog would know any time the trainer tries to fool it. The same applies to the fishing cormorants. Apr 27, 2017 at 23:08

Let's assume:

The bird has x baby birds, each baby needs y worms to survive.
So the bird perceives somehow that after y worms babybirds stop to cry. If the bird as fed all babies, he perceives the amount of worms he fed to the family. One day the family need more, the next day less. They perceive that 5 eggs are less than 4.

Of course they don't count! I'm talking about being able to abstract reality to put things into relation. Basic counting is understanding >,< operators and arranging the elements of a set in the right order(4>2<3>1)->(1<2<3<4).

Now if you teach him the name of relations he is able to grasp, like <,> and values(numbers) he could figure it out and count, because the relation is already in its mind. Teaching the relation is way harder, than just giving tools to apply know things to.

Pressure to develop this ability: Don't go for prey bigger than you, don't pick up more than you can carry, build the nest higher than last time, or the fox will get the eggs again. It is in the nature of our reality that most living things can under stand relations like this.

This could be a reason why he can count, no one knows why for a fact. Another possibility is he was just very well conditioned and good at mirroring humans.

• Birds tend to just feed until the cheeping stops, they don't think or count, just fly back and forth as fast as they can. If it's a good year more than 1 or 2 might get enough food to survive (depending on species) Apr 27, 2017 at 13:23
• I maybe written it too hard, i did not mean that the birds will actually count the worms they feed. They observe and notices 4 babies are less than 5. The point is not that they already had counted but got a feel for the volume of a set, a feel for <,> operators, which is the perquisite for counting. When they already know what > is its easy to teach 1<2 and 50>49. But teaching an animal to count which does not get the idea of "more than" seems impossible to me. Not selling this as truth, but my try of explanation why animals with human help can grasp numbers. Apr 27, 2017 at 13:44
• And no one knows that birds actually don't think. We dont know about how birds brain work. Some birds even create tools, our first trait that made us different right? Have you ever observed a raven? To me they look very intelligent. They even know when someone is raising a gun at them and fly away. If you take a stick looking like a rife and pretend to aim at them they wont fly. Apr 27, 2017 at 13:50
• It's believed that birds can count their eggs as there are various birds that drop eggs in other birds nests, so the ability to count becomes valuable there, but multiplication is unlikely. Apr 27, 2017 at 13:54
• Why u so focused on that. It could be written t=y+y+y+y multiplication was used by my to make it shorter. Any product can be written as a sum. In bird thoughts: for one baby i need (1 and 1 and 1) worm, for two babies: ( 1 and 1 and 1) and ( 1 and 1 and 1). Again not saying that birds know how to use brackets, only used them to make it cleaner. I even included somehow, to indicate that they know something equal to our term x*y=t. Try to understand what I'm saying before talking back. Apr 27, 2017 at 14:05