I was lying awake last night thinking about the posts on the Piranha bugs
scenario (I know, I know.... I'm shopping for a life this weekend). While I
have no problem with the idea of the bugs themselves, something about it
didn't quite stick right, and I finally put together my
thoughts/suggestions
on the subject.
Let me preface them by making a couple of disclaimers.
First I am NOT a biologist. If anything I say is incorrect, I'm sure Beth will
set me straight in her usual gracious manner. Heck, I'm not an expert
at ANYTHING -- but I am familiar with many subjects. Unfortunately,
the downside of being so easily interested is I am also easily distracted.
Anyone who knows me well but choses not to like me might even accuse me of
being a bit of a dilletante. But I think I've picked up enough to make this
make sense.
Second, I will be making some comments based on general observations. I in NO
way claim that ANY of these are hard fast rules. I will do my best to use
phrases like it SEEMS, TENDS, GENERALLY, etc. I know that any time you post an
opinion about a general trend, many on the list like to reply with some
example of something that bucks the trend. I'm well aware that there are
exceptions to these general tendencies, but I do NOT think that detracts from
the validity of the observations.
Having said all that, away we go:
I noticed that it was stated that there were numerous mounds of these bugs
within proximity to one another, While the bugs themselves are quite
believable, I have a problem with this. This is why. Colonizing insects
TEND to protect their nests/lairs VERY violently - as the scenario
attests. Predatory animals, particularly social ones, TEND to be very
territorial. Combine the two, as in Colonizing Predatory Insects, and you TEND
to get
animals that are EXTREMELY turf-conscious. I've seen footage of ants
going
at it with other ants over nests/territory - it ain't pretty. Makes
many human wars seem calm when taken in scale.
So these bugs aren't going to want bugs from another nest in their territory.
Fair enough. But why can't the territory be small enough that these mounds can
be within a couple hundred metres? Well, remember they're predatory. Predator
territories AS A GENERAL RULE have a relationship to the amount of food
required by the predator and the amount of food available. The more a predator
eats, and the more often it has to eat, the larger the territory it tends to
try to defend. And the frequency (even
more than the amount at any one meal) that a predator must eat tends to be
related to it's metabolism. And small, quick, active, flying animals (eg
hummingbirds) tend to need to eat more frequently. Which means these bugs
probably need to eat pretty frequently. This means that either the country
around them is carpeted in prey animals, or they must maintain a fairly large
territory. That's why I doubt there'll be many mounds close together. I could
be wrong. But if I ran them in a scenario, I'd have a nest
density of maybe 1-2/Km2....
Here's a short answer...why can't the nests be all from the same 'family'?
OG
> -----Original Message-----
> On 11-Jan-02 at 15:15, Brian Bilderback (bbilderback@hotmail.com) wrote:
> I noticed that it was stated that there were numerous mounds of these
I didn't think they were predatory...
Actually, that's easy. Don't treat each mound as a seperate nest. Each mound
is but a single "home" (or exit point) for a larger nest. There's no
particular reason that they couldn't be communal on a much larger scale,
especially since they're alien. Postulate some underground tunneling and
chamber and it's even easier. Then the distance to the nearest bug "nesting
site" could be quite large (which would also explain the locals lack of total
knowledge about the nasties).Then give a vehicle a chance to break through the
ground and fall into a main chamber! Yikes!
> From: "oglover" <oglover@bigpond.com>
The amount of prey needed would be staggering, since it was stated in the
original post that each MOUND contained millions of individuals. The necessary
hunting range would become prohibitive.
> From: Roger Books <books@jumpspace.net>
> I didn't think they were predatory...
The original post stated the humans were "Stripped to the bone." (not just
bitten to death) That indicates predation, don't you think?
Why 'prohibitive'? There is no indication of the speed of flight, duration
before return to nest, maybe loooong hibernation periods between periods of
activity, in which case they literally strip the cpountryside bare for
kilometers in diameter but sleep for 9 months or more between risings? So many
factors are unknown about the ecosystem these critters live in based upon the
short description in the game scenario.
> -----Original Message-----
Again, as I said in my reply to B Lin, the population size, whether single
colony or multiple, will be limited ny the ability of the food source to
sustain them.
Brian B2
> From: "Don M" <dmaddox1@hot.rr.com>
> oglover Wrote:
> Why 'prohibitive'? There is no indication of the speed of flight,
So
> many factors are unknown about the ecosystem these critters live in
Possible. But if this is the case, then those bugs are going to want the
countryside teeming once the fly to eat again. They aren't going to want
another colony nearby stripping i bare in the meantime. Which means
territorialism, which means one colony per given range. When they do fly, the
more there are, the farther out they have to fly to get enough to feed all the
bugs. Fly to far, and you're burning too many calories to justify the flight
for what you can collect from the kill. This means a relatively limited hive
population, to economize on energy.
G'day,
> I noticed that it was stated that there were numerous mounds
This assumes that the nests you see on the surface aren't just expressions
of one meta-nest. We may see them as separate colonies, but they may be
linked underground or be projections of a main nest and so be all friendly
together - think of the columns of Army ants and their offshoots when
they hit obstacles, each offshoot will look separate, but self recognition
allows them to join the main column again seamlessly when they meet up again.
So you could get away the density shown as the colonists may well perceive
them as separate colonies, but that doesn't mean the bug does;)
> The more a predator eats, and the more often it
Sort of. It has to supply itself yes, so their territories will be quite large
if there are many links in the chain before them as 90% of the energy in any
one level is lost, with 10% only making it to their predator to support them.
> This means that either the country
Or supplement with other behaviour, such as scavenging or farming. May well
be that different cast members have different dietary requirements too -
so the "strippers" are the "soldiers" who follow the credo of the best defence
is offence, whereas the bulk of the colony is based on eating farmed fungi or
wood boring or grazing of vegetation, heck they could even have symbionts that
allow them to be photo or chemosynthetic. Once again the colonists may not
have noticed minor details like that if its hard to do research on them
in the first place - all termites from afar can look alike (specks), but
up
close there can be major differences - thus the many millions seen on
the nests may not all be "strippers".
Alternatively the mounds may only be temporarily inhabited, the Piranha Bugs
may stay permanently on the move like Army Ants which do number in the
millions and can strip a horse. So the Piranha Bugs may move from mound
complex to mound complex as they strip whatever is in their path.
Yet another alternative is that the Piranha Bugs are actually just one stage
in the life cycle (so sort of the same argument as above, but a life stage not
a caste), and once they've "eaten their full" so to speak they reproduce and
die. Thus relieving pressure on the local surrounds until that life stage is
reached again.
Yet another alternative is that the ants take the opportunity of the food
presenting itself to do a raid and save them the effort of going to get
it -
much the same way as Army ants will forgoe their dawn raid if a large food
source presents itself at the door of their bivouac.
OK better stop now before I go through too many alternatives and make you want
to release said bugs on me;)
> Beth.Fulton Wrote:
> G'day,
Aee? I told you it would be nice.....
> > I noticed that it was stated that there were numerous mounds
So
> you could get away the density shown as the colonists may well perceive
> them
I can't argue with you there. What I would say is that if this is the case,
there's going to be one colony to deal with, not a separate one from each
perceived mound, which seemed to be the case in the first description.
> > The more a predator eats, and the more often it
Don't most predators in general tend to supplement predation with scavenging?
May well
> be that different cast members have different dietary requirements too
There'd still be a top end to the mass of bugs sustainable in a given area,
wouldn't there be?
> Alternatively the mounds may only be temporarily inhabited, the Piranha
> Bugs
True enough, and very likely. But it still suggests that there aren't going to
be multiple mounds each with it's own high population of bugs within one area.
That's the impression I got from the first description, and the one with which
I took most issue.
> Yet another alternative is that the Piranha Bugs are actually just one
True, but this still would support the concept of a highly territorial bug,
since they're STILL not going to want other colonies around during the
development of the next stage of bugs....
> Yet another alternative is that the ants take the opportunity of the
I like this. Like you, I see them more as flying army ants than as beeish
animals. But I still think there's got to be a limit to the number of them
that any given area can sustain....
> OK better stop now before I go through too many alternatives and make
Don't stop now, the more you suggest, the more cool ideas I get for future
use. :-)
G'day,
> Don't most predators in general tend to supplement predation with
Some. Some predators will only eat live meat (e.g. many predatory reptiles),
some will scavenge (e.g. lions, hyenas etc), but others supplement with
vegetation (e.g. humans;)) or even photosynthesis (e.g. corals). Really
depends how strictly you define predator;)
> There'd still be a top end to the mass of bugs sustainable in
Yes, but there is no mention in the report of what food sources are available,
how bug an area they can cover etc. You could have a VERY dense colony if they
can cover a large area or there are very rich resources available.
> True, but this still would support the concept of a highly
Depends whether or not their is direct threat/competition at that time.
You quite often see animals cosying up nicely at one time of the year only to
be at each others throats at another time.
> Don't stop now, the more you suggest, the more cool ideas I
Well thought it prudent to stop and have you wanting more.... I also had to
go and do MEGA house-cleaning duties seeings as parents-in-law arrive
Thursday...
Cheers