That’s a great question, but obviously unanswerable. Unless you’ve got a time machine, we can’t determine the changes in ecology of the regions inhabited by passenger pigeons or dodos. Accounts from a 150-200 years ago aren’t specific enough and certainly didn’t display the sort of scientific rigor needed to determine what the changes have been since the demise of these species.
A lot of people will be tempted to say: if we can’t know, there must have been no environmental damage done. Consider this hypothetical: What if rates of herbivory by rodents are 4 times higher now than they were before the passenger pigeon were eliminated (suppose the pigeons carried diseases that were easily transmitted to the rodents, keeping their populations down). How would we separate this out from the effects of habitat destruction, changes in vegetation do to increased cultivation, and hunting that was all happening at the same time as the elimination of the pigeon?
We might not only be completely unaware of the environmental damage caused by extinction of a species, we might also be completely unaware of the human damage - rodents are a major problem for farmers. We would just shrug and accept it and assume it’s always been that way.
My younger brother (who lives in Florida) once argued to me that, since manatees don’t have the ability to protect themselves from boat props, perhaps they should be allowed to become extinct. He claimed they serve no useful purpose, anyway.
I don’t agree, by the way. He’s just kinda sick, sometimes.
I vote for the vampire bat. Yeah, I know they don’t attack many human beings. I’ve just never figured out any benefit they have to man. Let me know if I missed something. Other bats are great, but the vampire bat, not so much.
There might one for the dodo. It was believed by some that the DODO TREE on the island of Mauritius where the dodo was found could only germinate after its tough-hulled seeds had passed through a dodo’s gizzard. Some dispute this theory however.
If this is a serious answer, why should there be a benefit at all? What is the benefit or useful purpose to man of manatees anyway? Why is it sick to dispense with manatees but not vampire bats? I’m curious. Don’t you think this argument is specious? Even more so because I doubt you will ever see a vampire bat in your life and it bothers me that you would wipe out an entire species because you find it icky.
Agreed. Look guys, the experiment just isn’t working; it isn’t that we don’t appreciate the comical cartoon look, but to be honest, racoons pull off pretty much the same act with a great deal more enthusiasm and badgers do it with menace, so what are you bringing to the table?
I know your diet makes you lethargic, but if you’re not going to even take an interest in sex, then just die out already.
As well as several species of fish, and insects, too.
While we really only notice mosquitos in their adult phase, we forget that there’s a huge winnowing going on at every stage of the life-cycle. I think it’s fair to say that the population goes from egg, to nymph, to adult (with possibly several intermediate nymph stages) and gets cut down by orders of magnitude at each stage.
Well, gawd, Pedro, good to see you’re taking this in the spirit in which it’s offered.
My brother’s proposition disgusts me because: he’d like to see laws protecting manatees, and funds & efforts dedicated to their preservation, eliminated simply because it might inconvenience him as a recreational boater.
I came up with the vampire bat because: unlike other species of animals I can think of, I’m stumped when I try to determine what positive effect they have on (1) the environment in general, and (2) mankind in particular, and in fact it appears to me that their very means of sustenance causes harm to other living creatures in a way that I don’t seem to be able to appreciate. But, I qualified my answer by expressing the willingness to reconsider if someone shares with me information that demonstrates their importance in the ecological “big picture.” (By the way, the “icky” thing was ridiculous; I’d already mentioned that I’m a big fan of bats in general.)
What species has a positive impact on the enviornment? How do you measure that? By who’s standards or for who’s benefits. It sounds like you are making the exact same arguement as your brother, just hiding it in fancier language. I don’t like it, so it must not be worthwhile.
On a slightly more serious note: I think that the vampire bats (actually several related but different species, IIRC.) should be given emphasis for protection, if it should become necessary. “But, Loki, why?” I hear you cry.
Well, to sum it up in one word: Kidneys.
More specifically, it is common knowledge that desert dwelling mammals have some of the most phenomenally efficient kidneys in the animal kingdom. The desert dwelling kangaroo rat pisses out a paste, because it’s so wired to conserve water. What is less well-known is that the vampire bat’s kidneys are almost as efficient.
“So what? You just said that other mammals have even more efficient kidneys than the kidney bat. What’s the deal?”
Well, basically it’s because the kidneys of the vampire bat have two modes of operation. When the bat feeds, it does so by landing on a large mammal, cutting into the skin of the beast, and drinking the blood that wells through the cut. But remember - bats are flying critters. As such, they are worried about weight. And blood, even more than most food substances, is very heavy per caloric content, because of the high percentage of the blood that is water.
So, even while the bat is feeding it’s going to be pissing out water absorbed from the blood it’s drinking. At this stage, the kidneys of the vampire bat are as wasteful (in terms of water expelled per unit mass of nitrogenous waste) as any in the world. This keeps the weight of the meal in the bat’s stomach down, so that once it’s done feeding, it can fly off.
Then, when it’s in a safe place, it will digest the blood. And blood, by its very nature, is a nitrogen-heavy food. So, the bat now has relatively little water in its body, and a whole crap-load of nitrogen watse to dispose of. So, now the kidneys are working in a completely different mode - conserving water, because it’s now a rare resource.
Vampire bat kidneys are just too neat to allow to be lost.
I’m not SURE this is the case, but it is possible that Vampire Bats mostly feed on sick, weak, etc animals, keeping populations intact and possibly stengthening them.
Brian
When it was at its peak the passenger pigeon was the most numerous species of bird in North America, quite possibly the world. Indeed I have seen some speculation that the number of passenger pigeons alone rivalled the number of all other North American birds put together. This would have been the normal state of affairs probably since at least the last ice age until the middle of the 19th century when the population started its irreversible decline.
The birds ate nuts, seeds, and berries as well as some insects and worms. You have to think about the impact this huge number of birds eating, say, beechnuts every year for millenia, then suddenly (and the population crash was sudden as these things go) disappearing. How would that affect the makeup of the forests? What kinds of trees might suddenly proliferate? What pests and parasites that these trees were hosts for would suddenly proliferate as well? What about hawks or owls or other predators that fed on the pigeons…their populations would be affected too.
The problem with answering your specific question with respect to the passenger pigeon is that it was well on its way out as a species before the dawn of modern ecological science. We don’t have systematic surveys of the forests or biodiversity of North America from the late 1700s, so we can never be really sure what has changed since then.
I’m guessing we could lose undersea tube worms without destroying all life on the planet.
…of course, if something else wipes out the rest of the life on the planet, there might be nothing left in the hydrothermal vent ecosystems that could evolve to repopulate the Earth, and inherit the reins of civilization. (So we wouldn’t even get to have our charred bones dug up by tube worm Paleontologists.)
