Food chain question

Is there an animal and/or plant that no other animal or plant wants to consume? Are there any plants and/or animals that are only consumed by bacteria once they are dead?

With extremely few exceptions…Man. Top of the food chain.

Man is consumed, even though rarely, by other animals. My question is are there any plants and/or animals that “never” end up on the plates of something/someone?

Food WEB, folks; it’s a food web.

[sub] nope, ain’t got nothin’ else to say[/sub]

How about the killer whale? Orcas have been known to kill and eat Great White sharks (there’s video out on the Web to be found with some searching).

As to ‘want to consume’, does this mean an organism that is, say, toxic enough that no other organism will consume it? I would imagine a dead Orca is still a feast to other opportunists in the sea. When it’s alive, it would be the apex predator. I would guess there are some organisms that are never preyed upon due to toxic defenses, but none jump right in mind. A dumb predator might eat one just once.

I would venture that even such highly toxic critters as poisonous tree frogs and the like are still disassembled, post mortem, by ants. Those little suckers are the arthropod clean-up squad for the entire world. It is hard to imagine any once-living thing that ants wouldn’t make a meal out of.

Killer whales and frogs aren’t going to work WRT the OP, since there are any number of parasites that bite chunks out of them from both the inside and the outside. Being too big and aggressive to consume in one mouthful doesn’t make them animals that nothing ‘wants’ to eat. The same goes for man. We’re eaten quite regularly by lice, fleas, worms, mites and other nasties. If we’ve got to restrict our definition of being ‘on the menu’ to being eaten completely and lethally in one sitting, then no plants I can think of are ‘on the menu’.
I suspect the answer you’re going to get to this one will be no. Animals, plants and their consumers evolve side by side. Any mutation in a plant or animal making it less attractive as a food source will result in an evolutionary advantage in those animals able to overcome those defences and the status quo is quickly returned. The only way around this would be if a plant or animal became so toxic so quickly that every single insect or animal that ate it died immediately with no chance overcoming the defences, or if the only consumer species was exterminated somehow.
There’s an additional problem when we add ruminants into the equation, since they are essentially mobile bacterial fermentors and able to digest just about anything organic. This makes the OP kind of dubious, since these animals actually eat living plants that are then converted into food by being digested by bacteria after they are dead.

Well, I know what you’re asking. The short answer is, “Yes, in general, plants with thorns, spikes, etc., and plants with poisonous, usually very bitter sap, are not usually eaten by herbivores, unless the herbivores are starving.”

But even the acacia, with its thorns, has giraffes grazing on it, and even poisonous plants will have animals that can eat them.

If you have nothing else to do this morning (Boss out of the office?), you should read your way through this whole “On the Evolution of Plant-Herbivore Interactions” website. Great stuff.

As for animals, I think everything counts as meat and has something that preys on it somewhere.

And actually, now that I sit here and think about it, you couldn’t possibly have a plant or an animal that wouldn’t be eaten by something, at some stage. Otherwise, you’d be talking about an indestructible species, like Superman. But even Superman had Kryptonite.

Imagine something like this Australian plant, gastrolobium, but with no herbivores willing to graze on it. With no checks and balances, it would take over the world.

Ditto for some animal, say poison arrow frogs. If there weren’t any predators on them, we’d have them everywhere.

So I guess the literal answer to your OP would actually be a definite “no”. All plants and animals have checks and balances that keep their reproductive rate under control so they don’t take over the world. This is how ecosystems work.

So, what about kudzu? I have heard that it is spreading throughout the southern United States and is very difficult to kill. I am pretty sure it’s not native to North America, is there something that eats it wherever it’s from that didn’t get transplanted when it did? Or do N.A. herbivores eat it, but not enough to kill it? I seem to remember that it tends to choke or shadow out most native ground cover and is resistant to just about anything short of roundup.

IIRC, goats do eat kudzu; however, it grows at such a rate (something like a foot a day, I’ll need to check that somewhere) that domestic goats brought in to eat it cannot keep up with it.

The problem with transplanting a native eater of kudzu (African in origin, I believe) is that we do not know how that new animal will affect the other plants and animals in the region.

As a hypothetical example: there are several non-native species of trees in Florida, brought in specifically to dry up the Everglades :rolleyes: for development, specifically I am thinking on Australian Pine. There is an insect (a wasp, I believe), that bores its way into the tree, killing the tree. Simple solution, bring in the wasps, release them, they kill the trees and everybody is happy, right?

Eh, a couple of problems crop up. What is going to happen to native trees once the Australian Pines are gone? It would be physically impossible to recall each and every wasp once the A.P.s are gone.

Best scenario is that the wasp population, devoid of its normal food, dies out completely.

Or (scenario) it could adapt to a new food, let’s say sabal palm. Now it has a virtual smorgasbord, but it is intruding on insects and animals that depend on those trees for food and nesting (not to mention the loss of ‘heart of palm’, really yummy salad ingredient). The new insect (the wasp) has no native predators, since birds and other critters are not going to immediately recognize it as food: result, population boom in the wasps.

Or, (scenario) the native birds and other animals suddenly get sick from eating this wasp, since it may have a body toxin that its predators in Australia have adapted an immunity to over countless eons, which our wasp predators have no immunity to this toxin. Result, severe loss of native populations of birds and animals, boom in not only the wasp population but other prey animals normally eaten by the wasp predators that have just died out.

Also, (scenario) there is the risk of new medical emergencies if someone is stung by a wasp and does not immediately recognize the symptoms or a different anti-venom is needed for this particular specie’s sting.

Similar scenarios occur with walking catfish, zebra mussels and thousands of other imported plants and animals to every country. Importing (deliberately or accidentally) any sort of non-native species, even as small as a plant or insect, can have devestating effects: note the problems with the Mediterranean Fruit Fly on the citrus industry nationwide. Water hyacinth was imported into Florida as a pond plant. Somewhere along the line, someone decided to cut back the weeds since they were choking off their pond, so they threw the plants into the canal and waterway behind the house. Voila, it takes root (and really deep roots, at that), and now the state and counties are spending millions of dollars annually on water hyacinth eradication, not to mention the loss of native fish and prime fishing areas (lack of sunlight, oxygen and overabundance of nutrients in the water from the decaying plants), tangled boat propellers (no pleasure boating or water-skiing) and canoe oars (trust me, not fun extricating yourself from the mess), premature change in the natural path of the rivers and waterways, and just plain ugly weed-choked water.

In a nutshell,

I have a problem with a mouse in the house.
I get a cat, and the cat scares off the mouse.
Now the mouse is gone, but the cat is tearing up the house.
I get a dog, and the dog scares off the cat.
Now the cat is gone, but the dog is tearing up the house.
I get a goat, and the goat scares off the dog.
Now the dog is gone, but the goat is tearing up the house.
I get a horse, and the horse scares off the goat.
Now the goat is gone, but the horse is tearing up the house.
I get a camel, and the camel scares off the horse.
Now the horse is gone, but the camel is tearing up the house.
I get an elephant, and the elephant scares off the camel.
Now the camel is gone, but the elephant is tearing up the house.
So I get a mouse.

Mess with mother nature and you end up having to get a mouse.

We now return you to your regular thread.

It’s not quite that simple. Ecology never is.
Heart leaf (Gastrolobium), under natural circumstances, is controlled more by environmental factors such as lack of suitable seedling establishment seasons and by fire than it is by grazing. The densities of rat kangaroos would probably never get high enough to have a significant effect on plant populations. There are also insect consumers of heartleaf. Disease would also undoubtedly play a part.
In general few plants are actually kept in check directly by mammals, with insects, diseases and environment playing a far greater role. Of course all plants have a narrow environmental range they can tolerate that restricts their spread.
The same applies to animals. Most animals have a narrow environmental range, and few if any reach long-term plague proportions for two reasons. Firstly prey/predator boom/bust cycles keep the population in check and secondly because disease will kill them if population densities become too high (the main controlling factors in human population for 6000 years). Even cane toads in Australia have finally started succumbing to an unknown disease and numbers have been dropping steadily for the past seven or eight years. This is a poisonous species with initially only one predator with a restricted range (although lately some other natives animals have learned how to kill them). Poison arrow frogs have an even narrower environmental range than cane toads and would undoubtedly suffer the same fate if released elsewhere. Added to this poison arrow frogs released anywhere else would be nowhere near as toxic, since they apparently extract their poison from some unknown species of prey that is not found elsewhere in the world. Museum/zoo poison arrow frogs aren’t near as poisonous as wild specimens.

Ironically heartleaf becomes a problem under grazing by domestic livestock because they selectively don’t graze it, giving it more open ground to germinate in and removing grass which stops fires. There is a bug that can be introduced into the rumen of sheep and cattle that makes them immune to fluoroacetate and able to graze heartleaf, but everyone is terrified that if it is introduced it may find its way into rabbits or native animals. This isn’t very likely, but if it did then they would suddenly have a whole new food source with no defences, and could exterminate both heartleaf and a range of other native species that rely on fluroacetetae for denfence.

I’d never heard about Australian Pine in the everglades. Funny that you call it a pine when it’s not even a conifer. Hell we do the sensible thing and call it an oak when it’s not even related and doesn’t look remotely like an oak. That makes much more sense.
I have to ask what sort of moron would introduce a plant that’s a weed in its native environment into an area where there are no consumers. Ahh well, I can add that to my growing list of Australian plants that are weeds elsewhere. I can’t help thinking the pine, tea-tree, carrotwood, chinaberry, pearl tree, sea almond and eucalypts in Florida are fair payback for mesquite, prickly pear and a range of other American species we’ve had to put up with. (Just kiddding)