Predator & Prey Question

[foodchain]

For consumers or predators would simple abundance played a role in fitness and continue to do so? I mean if you reduce what a species can eat rapidly I think the impacts would be bad, but on that note could specie to specie fitness in such a relationship, such as predator to prey help a predatorial species by simply staying fit?

 

Such as if a Thompsons gazelle became a lazy specie that could not run very fast, I think it would be easy to think predators making such a specie extinct rather quick, but then that could be disaster for any predatorial specie, simply put what do you eat? This is a problem for bigger cats such as tigers in ever shrinking regions of habitable land.

 

So to reduce to something more abstract, if you say had to have a energy minimum to support some function, and that function could variate to mimic say variance in organisms, would not predation have a certain fitness to it based on a minimum if you look at its prey?

 

So I would think that any time I would be looking for a predatorial animal, I could think about population densities of possible prey in relation to any projected or hypothetical behavior. Such as if I wanted to study the life history of some predator species, such as lions, would existing populations of possible prey be a good place to look?

[ecoli]

obviously population density is important, but I think that directional selection would tend to eliminate the lazy gazelles in a population, I should think. Such animals would be easy pickings. The selection for faster not lazy animals would, in general ensure the survival of the population. I don't think the evolution of a whole population of lazy gazelles could occur in such a time frame as to put the existence of that population completely at risk.

 

Predators and prey tend to co-evolve, with evolution "checks and balances" with each other.

[pioneer]

In a healthy steady state ecosystem there is a good balance between predator and prey. But there are scenarios that can tip it out of balance. For example, drought for many years so water becomes limited. At this point, selective advantage may go those who can hold water better, even if they are slower. It may not go to lean muscle and speed since water storage may not be as good. The predators has more choice and may go after those who dehydrate quickest, since don't feel too good and now easier to catch. A few years later, the drought ends and you have water laden gazelle who now don't hold up well in a leg race.

 

Another drought scenario could be a limited food supply. The runts don't have to eat as much to stay full. The big buck is now on a diet. Dropping that weight quickly could take him out of his game. The little runt is still able to run his normal half speed of the once big buck. Because the big buck is a bigger prize and is now getable, it might become dinner for the predators. One hunt is better than multiple. Now we get another shift. In good times, the runts are sitting ducks.

[ecoli]

you mean sitting bucks