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Dave W.
Info Junkie
USA
26022 Posts |
 Posted - 04/12/2004 : 11:51:16 [Permalink]
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The Moloch
Named Moloch horridus by Dr. John Gray in 1841 - after Moloch, the king Milton wrote of who was covered in human-sacrifical blood; or Moloch, the Canaanite god - and also called the Thorny Devil or Mountain Devil, there is very little that is devilish or horrid about these lizards.
Mostly, they just want to be left alone. Most of their adaptations are defensive. They can change colors to match their surroundings (from redish yellow to brown to drab olive green); they can inflate their bodies when threatened; they move slowly, with jerky motions, in imitation of leaves; sometimes, they stand completely still with a leg in the air; using their tails, they exert counter-pressure if something tries to flip them over, and their spikes aren't used offensively at all.
Their strangest defensive adaptation is a "false head" which sits near their shoulders. When threatened, a moloch will dip its head down between its front legs, and the bump on the back of its neck makes a decent simalcrum of its head. The complete purpose of this organ is in dispute, with some suggesting it is a fat reservoir, and others suggesting it is purely a fake head. While no molochs have ever been found without it (indicating that it isn't something which can be lost to predators without harming the lizard), Dr. Eric Pianka (probably the moloch expert) once found a moloch with what appeared to be a scarred false head.
Molochs live on sand, almost exclusively. While they appear to enjoy Australia's roads as sources of heat, they don't like rocky terrain, and according to Pianka their entire range appears to be based upon where the sandy soil lies in Australia, rather than any sort of climatological preference.
For most of the year, molochs remain within a 20-to-30 foot square area. In it, there will be clumps of grass or small shrubs in which the moloch hides, lots of sand, a basking area, a location in which "neat" piles of fecal pellets are deposited, and at least one ant trail or mound. Specific sites for activities are used repeatedly over the course of a few days.
The ants are the molochs' food. Almost exclusively. A moloch will sit next to an ant trail, and using a sticky tongue, lap up ants at a rate which can approach 45 per minute. A single "meal" can consist of anywhere from 600 to 2,500 ants. Molochs have weak jaws, but specialized ant-crushing teeth. Perhaps due to their diet, moloch poops are glossy black spheroids.
Aside from what water they can get out of ants, molochs also drink whatever water collects on their backs and legs. Microscopic channels within their skin soak up water, and through capillary action and "pumping" with a gulping motion, this water is delivered to the corners of the molochs' mouths. It was once thought that molochs could actually absorb water through their skin, but due to the harsh environment, their skin is actually waterproof to avoid losing water. It's the channels in their skin which can hold a surprising amount of water, as after a decent rain, molochs can increase in weight by a gram.
And that's a pretty good increase, considering molochs tend to weigh less than 90 grams, full grown. And that's just the females. According to Pianka, nobody has ever found a male moloch which was over 49 grams. The males also tend to be about 80% as long as the females, which can reach 20 centimeters from nose to tail. But the females appear to need the extra size and weight, as they can lay clutches of eggs (averaging eight) which might represent 40% of their total mass.
Molochs seem to only take "long" trips (upwards of a kilometer) during mating season in the Australian spring. They gather together in small groups, and act much like other lizards, with courtship displays of head-bobbing, leg lifting, and perhaps even "fights" between males. Molochs reach maturity and begin these bahaviours at two or three years of age, and they can live in the wild for upwards of twenty years.
Females dig nests for their eggs, up to a foot deep. Even though the mothers take the time to back-fill the hole, and even hide the evidence of digging, the eggs sit in an air pocket underground. Moloch young can be up to six centimeters long, weigh up to two grams, and look exactly like tinier versions of their parents. They can spend up to five years growing to full size. Newly-hatched molochs eat their own eggshells before digging out of their nests.
While molochs fall prey to all sorts of animals, their most-frequent predators are humans (Australian aborigines) and bustards. Also, in the words of Pianka,Once, while tracking a medium-sized thorny devil, I encountered a sand goanna, Varanus gouldi, which I collected and preserved for later analysis in the lab. I gave up on finding that thorny devil -- its tracks just vanished into thin air. Six months later back in the USA, while dissecting the monitor lizard, I found that thorny devil in its stomach! I remain amazed that the thorny devil's spines didn't puncture the monitor's thin stomach wall. I also found another small thorny devil in the stomach of a racehorse monitor lizard, Varanus tristis. Raptors are also probable predators of thorny devils. I cannot find a definitive source to confirm that the molochs are an endangered species, but about half the web sites I visited claim they are (with several other sites claiming these lizards are common and in no threat).
And back to the moloch's spikes... The moloch is apparently used as a textbook example of convergent evolution. It and the horned lizards of the American southwest and Central America have both evolved into specialized ant-eaters, and look remarkably similar, although not all that closely-related genetically. They're both covered with horns and spikes, remain motionless for hiding, and can puff themselves up. These are decent defenses for something which sits in the open and eats for long periods of time. But while the horned lizard's head spikes are actually bones which grow from its skull, the moloch's spines are entirely skin and scale, with only small "bumps" of bone underneath. What we see, in other words, are two different methods of making the same structures, on animals with similar needs, but which don't share a very recent common ancestor.
It's a real shame, too, as a moloch which shoots blood from its eyes (as some horned lizards can) would be really freakin' cool.
References and Photos (lots of photos in the links below): |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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LizW
Skeptic Friend
USA
113 Posts |
Posted - 04/12/2004 : 16:52:24 [Permalink]
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Hi Everyone,
I am a long time lurker, as my Hubby practically lives on this board. I have often wanted to add my own two cents on various topics, but usually I get through the threads long after the really interesting battles are over.
I feel compelled however to defend my cicada squeamishness. I know just as well as everyone else that cicadas are not dangerous. They are, however, BIG (in terms of bugs found in this area), if I remember correctly. A good idea of them is to look at your thumb from the knuckle to the tip and subtract about a third of it and then mentally add a pair of wings about 1 1/2 to 2 inches tip to tip (I am working from memory here as I have no urge to go looking up actual cicada stats). They are also fearless. This means that they will fly right into you or crawl onto you without provocation. Also, there are - scientifically speaking - a titanic buttload of these things, they do not come out in small well-behaved groups, they are a wave of Hell's Angel bugs.
Personally, cicada song doesn't bother me, the people who do little cheesy pieces on the news about eating them don't bother me (I am not so naive as to think I have not eaten worse things than cicadas), even the little exoskeletons they leave behind don't bother me (I actually think they are sort of cool), but no matter how benign an insect is, there is something about a jillion of them showing up all at once and pitching themselves at your face for two months that could make anyone a little skittish.
Whew! I feel alot better now! |
You learn something new every g****mn day! |
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Kil
Evil Skeptic
USA
13477 Posts |
Posted - 04/12/2004 : 20:30:08 [Permalink]
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| Welcome to SFN Liz! (Not that you haven't been dealing with our little site for awhile...) |
Uncertainty may make you uncomfortable. Certainty makes you ridiculous.
Why not question something for a change?
Genetic Literacy Project |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/12/2004 : 21:06:22 [Permalink]
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Hi Liz, and welcome!
Not trying to rub it in, or nothin', but I've been looking forward to the upcoming hatch ever since the last big one died away. 
Say, how 'bout giving us a small addition, here? What creature(s) do you consider the most unlikely / beautiful / weird / disgusting, and so forth? Please don't write about your neighbors dogs or children, just the righteous stuff. 
Dave, I was going to research the Moloch after you'd mentioned it, but never got around to it. Now, I don't have to.
Thanks!
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Dave W.
Info Junkie
USA
26022 Posts |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/13/2004 : 03:26:23 [Permalink]
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I was going to research them 'cause, while I know a little, I don't know much. Or didn't before, anyway.
Australia has wildlife import/export laws that are all but draconian, as well they should be. It is unlikely that we'll ever see a Moloch in the flesh, short of dropping in on Gezzam.
I was struck by the parallels with our Horned Lizards. In many habits and habitat, they are quite similiar, if not in appearamce. I would love it if someone were to call me to, "Come get this thing!" and find it to be an illeagle Moloch (I do wildlife rescue and rehabilitation, and problem snake removal, state licensed, and get these sorts of calls, now and again). It would be a very interesting animal to keep, albeit there might be problems with such a specialized feeder. But usually, those can be worked out.
Again, good read!
Edited to add: I've gots another in the works, a very strange and wonderous creature. It'll be a couple of days in the making, and I'm not going to tell you what it is beforehand. Someone else might be doing it even as we speak, and the articles thus far have been so good, that I'd just as soon read it as write it. 
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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| Edited by - filthy on 04/13/2004 03:45:38 |
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Dr. Mabuse
Septic Fiend
Sweden
9688 Posts |
Posted - 04/13/2004 : 05:42:30 [Permalink]
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quote:
Originally posted by LizW
Hi Everyone,
Hi LizW and Welcome! |
Dr. Mabuse - "When the going gets tough, the tough get Duct-tape..."
Dr. Mabuse whisper.mp3
"Equivocation is not just a job, for a creationist it's a way of life..." Dr. Mabuse
Support American Troops in Iraq:
Send them unarmed civilians for target practice..
Collateralmurder. |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 04/13/2004 : 20:40:09 [Permalink]
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filthy wrote:quote:
It is unlikely that we'll ever see a Moloch in the flesh, short of dropping in on Gezzam.
Even that only gets us to within about 1,000 km of moloch territory. And then you've gotta find the little buggers.quote:
I've gots another in the works, a very strange and wonderous creature.
I'm still waiting for some wise-ass to write up H. sapiens: "Believe it or not, its mating season is all year long! It uses tools, and language! Opposable thumbs! Nearly hairless! Can't smell a damn thing, and their hearing sucks, too! Bipedal! Etc!"
Hope I didn't ruin anybody's fun. If I did, try it another way, please... |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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LizW
Skeptic Friend
USA
113 Posts |
Posted - 04/14/2004 : 08:47:10 [Permalink]
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Thanks for the nice welcome,
As for a small contribution, I have been wracking my brain, and I still haven't thought of anything that would really wow you. I do believe however, that everything alive is unlikely, beautiful, weird and disgusting if you take a deep breath and look at them as if you have never seen them before.
There is one bit of man made animal weirdness that gave me brain sprain. I saw a show on the Discovery channel where they were culturing human tissue on living mice. There was a mouse running around with a human ear growing out of its back. There is not a spot in my brain where this image fits comfortably, it is like trying to swallow a tree, sideways.
Sorry I was not more on topic.
Filthy, I loved reading about the Pipa pipa. Now I am going to have to find a way to see one.
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You learn something new every g****mn day! |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/15/2004 : 00:48:01 [Permalink]
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Liz, you might try a large pet shop. They occasionallt have them for sale to aquarists. Failing that, many public aquariums have them on exibit.
So many strange ones, so little time.........
It is now almost 4 am, the hour of the coffee-swilling Zombie. 'Tis the hour for another.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/15/2004 : 01:16:37 [Permalink]
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Heterocephalus glaber.
quote:
ROLE MODELS. Naked mole-rats could be animal role models for little old, bald men with poor eyesight and bad hygiene who don't go out much.
And who does that remind you of?
http://www.news.cornell.edu/releases/July96/molebook.hrs.html
Oolon Coluphid was talking about to adding this species to his God's Greatest Mistakes list and at first, I opposed it. Then, after a little discussion, I agreed. Now, I've changed my mind again; this animal is just so damned good at what it does that it can't be a mistake. I don't know if Oolon's going to use it or not. At last report, he was still deciding.
The problem is, I think, that when compared to other burrowers, Mole Rats simply aren't very well designed for it. Or are they?
Naked Mole Rats are the only mammal known to be eusocial; that is, live in a hive society like ants. They have a single, breeding female as a queen, a few breeding males and soldiers, all of the rest are workers. Their larger colonies might contain hundreds of individuals and their tunnel systems can cover a vast area.
About the size of a gerbil, they can move as quickly backwards as forward, and their skin is so loose that they can all but roll over in it. The Queen Rat dominates the colony, or hive if you insist, by her behavior, preventing all other females and all but a few males from breeding. They spend virtually all of their lives underground and they deposit their body waste in a special chamber in their network of tunnels. All of the colony tracks through it, thus their collective scent is the same from rat to rat. If a strange rat enters the burrows, it will smell differently and be instantly attacked by the Soldier Rats.
The Mole Rat's main predators are snakes, including a Mole Rat specialist called, who'da thunk it, the Mole Snake. And these too, are fought by the soldiers. In fact, any disturbance in the colony will attract soldiers to the scene like angry hornets. Due to their powerful jaws and huge incisors, they are capable of inflicting serious wounds upon an optimistic reptile.
As might be expected from their subterranean life style, their eyesight is poor. But their sense of smell is excellent.
These have the strongest jaw muscles of any mammal of it's size, and it needs them. As it's legs and feet are not designed for burrowing, it digs it's elaborate tunnels with it's incisors. Like all rodents, these teeth grow constantly, so digging with their teeht does no damage. It has an unusual adaptation for this: excess skin on the sides of the mouth that fold in and act like a valve, preventing soil from entering the throat and choking it.
Their skin is another remarkable adaptation. As mentioned, it is hairless and very loose and wrinkled. Thus, it harbors no exoparasites and the wrinkles help the animal to dissipate or absorb heat. It needs this last because it is the poorest known thermoregulator among mammals. It must use the ambient temperature of it's tunnels to regulate it's body heat, rather like a reptile. When the colony sleeps, all of the rats huddle together.
Dig, we must!
Excavating tunnels is a team effort. Like the sand hogs of the nineteenth century digging New York City‘s tunnel systems, a rat or two works at the face, taking out large bites of soil. others move the soil back until, progressively, it is pushed out to the surface. With the exception of the Queen, breeding males, and the soldiers, all members take part. And more than one tunnel or chamber might worked on at any, given time.
quote:
Despite the fact that they burrow underground like mol |
"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Dave W.
Info Junkie
USA
26022 Posts |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 05/03/2004 : 12:38:13 [Permalink]
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Just wanted to update everyone: there are more and more little holes in the ground near the trees these days, meaning Brood X of the periodical cicadas is getting closer and closer to emergence. During a radio report I heard on NPR, some bug expert in Maryland even showed the interviewer a nymph just underground, near its exit hole.
I'm so excited. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 05/03/2004 : 13:54:32 [Permalink]
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Thanks, Dave. I am just starting to look for nymph cases on the trees. When I start finding them, I will go out in the late evening and early mornings with the grandthugs and catch a few to show them the wonderful transformation these insects go through, as I did with my daughters. Perch them on a stick in a small aquarium and you can watch the whole thing.
Then, when nobody's looking, I'll feed them to the copperheads! 
I started another species a couple of weeks ago, but can't seem to get back to it. Not a block, just laziness. Gimmie a little time.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 05/03/2004 : 18:31:34 [Permalink]
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Okay, filthy, it was pretty sick of you to perch your daughters on a stick in an aquarium to watch them become adults. 
Another tip from the radio report about the cicadas: put a trashcan lid on the ground over some of the holes: you're sure to catch a few of them, that way. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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