Note, this is a slightly different question than can be found here.
In the movie Zootopia the ratio of prey to predators is empasized in a dramatic scene as 10:1. In fact, it is a relatively important plot point driving motive within the film.
Gven that in the real world such a ratio is heavily driven by predation and usually fluctuates quite a bit, and given references in the film to population and reproduction of prey species, is that ratio really accurate? Too, how stable would it really be?
I am looking for both in universe and Canon out of universe (e.g. director/write comments/quotes) to support any argument otherwise and if any thought was given to why 10:1 was chosen vs. say 100:1 or even 1000:1. Alternatively, if we completely ignore the laws of biology as we know them, why wouldn't the ratio be only 5:1 or even 1:1?
My suspicion is that the ratio so vocally stated in the film was simply an easily understood 'round number' quote that easily rolls off the tongue. Something along the lines of "We outnumber you 10:1 which gives us the right to do what we want!" Whereas "We have exactly the same number of people on our side as yours thus we have a moral right to do what we want!" doesn't quite sound as impressive.
Some thoughts I have already considered on this:
Evidence from within the film supporting why the quoted ratio might be inconsistently too low:
As the train is leaving BunnyBurrow we see a sign which includes a real time population counter. The counter starts at "081435816" which is ~81.4 million rabbits, and is going up rapidly from...5810 to ...5816 in 2 seconds. That is roughly 3 rabbits per second increase.
Along with number 1, we learn that Judy has 274 siblings presumably none whom have been eaten by a Canadian Lynx
Mr. Big's daughter goes from preparing to get married to having a children within a very short time. Not that it is impossible that she could have been pregnant when she got married (like that never happens to humans :-)) But, I think the implication is that she is going from married, to pregnant, to having children very quickly
Technology seems to have removed most non-predatory population pressure items such as food shortages, etc. which might otherwise keep a population in check.
Hence, in the absence of predation, an abundance of food, and obvious fertility, why wouldn't the ratio be much higher than 10:1?
Possible reasons from within the film why the quoted ratio might be inconsistently too high:
Replacement of predation with other mortality factors such as:
a. Obesity (from eating daily sugar popsicles) b. Vehicular accidents (from wild driving and police chases) c. Modern day job stress (unless you are a sloth :-) ) d. Higher than average Organized crime death (some of the highest murder rates in the U.S. were during the gang wars during prohibition). e. Caste style poverty for some prey species which may cause less access to medical care and shorter lives. An example on the predator side of this might be foxes who seem to have discrimination in how they expected to behave thus limiting job and advancement opportunities.
Outside some specific prey species, voluntary decrease in population growth. We see this in humans who are actually slowing population growth in the absence of predation. Among humans, certain ethnic and religous groups still tend to have higher than average birth rates. E.g. perhaps bunnys and rodents are the only prey species that still reproduce at such prodigious rates. If others have decreased their birth rates, that may be enough to offset to a 10:1 or less ratio.
Thanks.