This is a collection of various emails about the affects that other (pest?) species (like cockroaches, mice, prairie dogsetc.) have, and why NOT to just "wish them away".
>
> Would we object if cockroaches, crows,
rats, mosquitoes, or mice went
> extinct? Aren't the prairie dogs nearly
as verminous to those who run
> livestock as mice & cockroaches
are in houses -- and rats are everywhere?
Well, beyond the rejoinder, why should I give a rat's ass about the eastern grey squirrel to make the point perfectly obvious there are a least a zillion other reasons.
You were at least not in too much trouble until you picked on mice - and for that matter rats. If you didn't already know, not all rats and mice are the same. In fact, they are damn different from anything your comments might imply. Since there are only roughly some several hundred species of rats and mice, I'm not going to bother with a blow by blow detailed description. Suffice it to say that they have their part in the grand symphony of the planet. A pretty big and useful part that hits on every octave. If you want a simply example, when the white footed mice in my old house where large in number cockroaches were scarce as hen's teeth. When they were rare, the roaches were bolder than all get out. Of course, if you have to have it in more economic terms in these post-Reagan years that we may never grow out of, suffice it to say that a single species of Peromuscus - there are dozens- will eat their weight in crop pests so fast you simply wouldn't believe it. And with their large numbers, high metabolisms and ability to evolve, they can run the red queen's race with core bores and what not much better than Monsanto and still not trash the water table.
I study mice of many shapes and sizes and types. So, perhaps I'm just a bit biased, and perhaps that is why it pleases me to notice a Reithrodonomys climbing a Solidago for lunch while I wait for a deer, or a Microtus dashing across my boots while tromping for pheasants, or a Peromyscus doing an Acapulco swan dive from a tree as I climb up to survey for the Big Guy. Little things that keep me happy. Did a jig this summer when I caught only the second Pergonathus seen in Iowa in the last 15 yrs. I guess we all get turned on by different things and that's reason enough for me.
But, if you must be more practical and if you like the play between grassy glade and thick forest, or the interesting texture of different species of oaks and beech and maple and whatever other species of trees you have in your neck of the woods, you need mice. You need them all. They all do different things and those different things hauling nuts and seeds hither and yon, and eating this plant instead of that one, and that bug over another, and some even eating each other. Makes for the variety of small single notes that together are the integral nuts and bolts that make the symphony. The world would look mucho different without them and I care, if you don't. So do a lot of other folks.
And then there are pdogs. They are not mearly another rodent. The literature is rife with a poorly quantified phenomenon called the Keystone Species Concept. As difficult to measure as anything can be, it is nonetheless clear that pdogs are to the prairies what beaver are to the northern forests. They are more like bison than bison. They do shit that others don't. More things live in prairie dog holes than prairie dogs. In addition, they shape the vegetation, creating greater heterogeneity than would otherwise exist. The dog towns are among the first places in the Badlands that the big ungulates like antelope and mulies and bison graze in the spring because the vegetation that grows there greens up faster in part because there are different species of plants and in part because there is no insulating layer of litter to shade the ground and slow the first growth. Since strong mommas in springtime make strong tykes, prairie dogs are a good thing in my book. And you don't need to watch a golden eagle or bobcat hunt one down to see the utility in having a quality grocer in the neighborhood. - oh yes, some damn cool mice live out in those pdog towns too.
>Would we object if cockroaches, crows, rats, mosquitoes, or mice went extinct?
I would! As much as some of them can be pests at times, they do serve useful purposes. For example it is doubtful that there would be any caribou migration if it weren't for the mosquitoes urging the caribou on. They are a part of the system. A pesky part for sure, but still a part.
> >>Would we object if cockroaches, crows, rats, mosquitoes, or mice
went
> >>extinct?
> >
And the dreaded blackflies pollinate the bluebberries, too.
> >suffice it to say that a single species of
> >Peromuscus - there are dozens- will eat their weight in crop pests
so fast
> >you simply wouldn't believe it.
>
> Are they then not themselves crop pests? Remember,
I'm
> asking. It may be obvious to you, but I don't know.
The net balance is way in favor of them, and all those little dickie
birds increasing crop yield, even if they eat some of it (but again, this
is species specific to the mouse AND the crop). The bottom line is
that corn is tough to eat when it's way up there on the stalk and in a
husk. But of course, they do if they have to. The amount they
eat falls way short of the corn that the pests take out.
> >And with their large numbers, high
> >metabolisms and ability to evolve, they can run the red queen's
race with
> >core bores and what not much better than Monsanto and still not
trash the
> >water table.
>
> Here you lose me -- not to disagreement,
but to
> incomprehension : I just don't see how to
read the sentence nor what it
> means. Is there something left out??
Yeah, it's sort of oblique. Earl makes me do that :). The
bottom line is that pests can't evolve defences against these sorts of
predators the way they can evolve resistance to pesticides. This
is because the predators evolve with them, and that is the red queen of
evolution - the evolutionary arms race where all the combatants run and
run and run, but each neither gains nor looses appreciable ground in the
battle for victory.
> >But, if you must be more practical and if you like the play between
grassy
> >glade and thick forest, or the interesting texture of different
species of
> >oaks and beech and maple and whatever other species of trees you
have in
> >your neck of the woods, you need mice. You need them all.
They all do
> >different things and those different things hauling nuts and seeds
hither
> >and yon, and eating this plant instead of that one, and that bug
over
> >another, and some even eating each other. Makes for the variety
of small
> >single notes that together are the integral nuts and bolts that
make the
> >symphony. The world would look mucho different without
them and I care,
>
> >if you don't. So do a lot of other folks.
>
> This is exactly the kind of thing
I was pointing out that
> I do not in fact know, and would
like to know more about, at least.
Some excellent work is being done in your neck of the woods by a friend
of mine. Peter Smallwood at U. Richmond on tree squirrel foraging
behavior. It turns out that the dietary pickiness of squirrels shapes
the mixtures of red and white oaks (and perhaps a lot of other species
of trees too) in your eastern forests. Right now, he and Mike Steele
at Wilkes are trying to figure out how this might translate into the reforestation
of the entire eastern US following the retreat of the Pleistocene glaciers
and the associated climatic change. But at a smaller scale, you can
often see evidence of squirrels out there changing the face of the forest.
The mice, of course are also doing their thing in this regard, but Peter
likes to focus on squirrels because they are easier to observe directly.
I like a little more challenge so I stick with mice.
> >And then there are pdogs. They are not mearly another rodent.
The
> >literature is rife with a poorly quantified phenomenon called
the Keystone
> >Species Concept.
>
> Concepts I
delight in still more than facts ; and that's
> a new one.
What is it??
The idea is that there are some species that, because they have many direct links to many other species and, perhaps because they significantly modify the environment, they are of fundemental importance to the state of the system. A closely related concept called the Ecological Engineer is very similar but more modern. If you want a few citations, I can give you some classics. The KSC is one that was first invented by Bob Paine who worked in intertidal benthic species (mollusks, clams, barnacles, starfish, snails) in the rocky intertidal zones of Washington. But that concept has been adapted many times over, and pdogs are a unanimously elected member of the Keystone elite.
It seems to me that we are always assuming that we are the axiological measure; and acting on that; and making very large mistakes. If you really _could_ remove all the mice and rats, it seems unlikely to me you could have the squirrels. I have seen small-scale perturbations, as when in a river camp bounded largely by cliffs and the mainstream, the boyscouts killed the snakes. Then we had thousands of mice; the ground writhed with them at night. Then we had dozens of skunks, which when the mice were gone attacked people's food. There is nothing quite like eating buttery popcorn and awakening to the cool, mobile french kisses of a striped skunk. Then with the mice gone the hawks moved out. Finally the oscillations of the system settled. For 10 acres of river camp writ small is Aswan Dam writ large.
As Brent points out, there are mice and mice. My favorite mouse is a little fellow out in Canyonlands -- Grasshopper mouse. Howls like a tiny coyote, trap-robs sets for other mice by killing them with a single bite to the atlas area and eating the soft innards, a 'mouse,' with all the signs of a tiny pack hunter. Grasshopper mouse, because that's what they eat - when they can't get other mice. With some odd inefficiencies in their behaviors, as if seed-eating and meat-hunting were a very recent exchange, evolutionarily.
None of us has the breadth of soul or knowledge to serve as the ecological arbiter.
> > Grasshopper mouse: They have neurotoxic venom too - quite
the little package of fury.
>
>How do they deliver it? My understanding is they have long sharp
rodent
>teeth. Hollow? Saliva dripping?
>
Yes, they have rodent teeth (1 pair of incisors up and down), and they can't inject but it gets in somehow. It would be about the equivalent of a bee sting I'm told. Have yet to experience it. Short-tails shrews also have neurotoxic venom. I saw a video of an Onycomys leucogaster killing a Peromyscus of some type. Pretty much just a quick bite and then track it down to where the mouse lies convulsing for a brief moment.