It doesn’t tell us how to avoid being eaten, or by itself tell us the best strategy, but it doesn’t give a wrong answer. Thinking in terms of individuals might give a wrong answer in that it ignores kin selection, which would be relevant if members of the herds or schools tend to be related.
Kin selection only applies if the behavior in question is altruistic (that is, the behavior increases the fitness of another, at the cost of oneself). There is no evidence that herding & schooling arose as altruistic behaviors; quite the opposite, actually.
It may be true that the flamingo population, as a whole, would be better off if all the individuals scattered. If so, than why would the crowding instinct be so pervasive within the flamingo population?
One could equally ask why humans have a tendency to steal, to lie, to murder, even when these actions are acknowledged to harm the overall integrity of the species / population. The answer, of course, is that while these actions often negatively affect the group, they simultaneously benefit the individual perpetrator.
So, let’s assume that the Flamingo population started off with each individual scattering upon sight of a predator. This would remove members of the population that were not strong or smart enough to evade a predator, while minimizing the number of casualties for the population. This population is apparently ‘stronger’ than a crowding population.
However, let’s now allow for mutations to occur within the population. Some individuals develop the instinct to run, not in a random direction, but consistently towards areas of the group which are the most densely populated. This individual flamingo thus acts to insulate himself from outside predators, making it much less likely that this flamingo will be eaten.
This is such a good trick that this mutation spreads through the entire population, and eventually everyone has the instinct to race toward the crowd. Thus whenever danger appears the flamingos all race inward, toward the group as to avoid the attacking predator. In this race, certain flamingos end up losing as they are stuck on the outside perimeter. It may very well be that the population has ‘evolved’ in such a way that there are more overall ‘losers’ than in the original scattering population. It evolved in this direction entirely because of the pressure between individuals to increase their personnel safety.
I imagine this has to be the primary advantage to flocking and herding instincts. 100 flamingos means there are 99 more flamingos on the lookout for predators.
For no real reason, here’s a video of baboons hunting flamingos.
That is the most satisfying explanation, IMO. The animals with the strongest flocking instinct are more likely to be near the center of the flock/school/herd, and thus less likely to be eaten. So evolution selects for a strong flocking instinct.
Thanks to everyone who responded.
OK, but surely the clumping behavior we are talking about is a lot more extreme than normal flocking or herding, and it happens after a predator has been spotted.
Very interesting, thank you.