I’ve often wondered if (in the animal world anyway), there are certain animals who have no predators at all, who no other animals will eat.
I was thinking along the line of those pretty but deadly arrow poison frogs in the jungles, is there anything that eats them?
Point of clarification: other animals don’t eat them because they are inedible only (arrow poison frogs, presumably), or are you also asking for animals in a geographic niche where no predators remain, although they’d be edible in theory? Could be two different lists.
I was thinking more in the line of absolutely inedible animals (i.e. inedible by human standards), where the food chain has not been broken, and all predators and their prey would be present and active. (Is there such a place anymore, with all of the habitat destruction going on?)
So, do (or did) arrow poison frogs have any natural predators that could safely make a meal of them (without croaking??) – (Sorry, I couldn’t pass that up!)
The bison on the plains of North America have no natural predators any more, simply because they are too large for anything else to kill them. I believe that they were formerly hunted by North American lions, but those went extinct in the last ice age. No new predator arose to replace them. There were wolves in many of the same habitats until they were driven out by hunters, but wolves aren’t large enough to hunt bison.
As far as I know, nothing eats the more poisonous species among the Poison-Dart Frogs - at least, I have never heard of anything eating them.
Many rather poisonous species are eaten by specialized predators. For example, toads (bufo) have pretty poisonous secretions that will fend off dogs and such, but there are several snakes that specialize in eating them.
Adult elephants, rhinos, and hippos are pretty much immune from predation due to their size, though big cats or crocodiles can take babies.
Larger animals may still act as a food source for parasites e.g. ticks & mosquitos.
The concept of a food chain has largely been abandoned by ecologists as it implies an hierarchical relationship which does not hold in practice. They normaly refer nowadays to a Food Web as it allows for more complex relationships, e.g.:
Mosquito feeds on man.
Trout feeds on mosquito.
Man feeds on trout.