Mary's Monday Metazoan: Frightening? It's like being attacked by an umbrella

Frightening? It's like being attacked by an umbrella.

Tell that to Georgi Markov.

One of the (very few) advaatages of a slow internet connection is that I get to see the headline a good few seconds before I see the picture, and to guess what kind of animal is umbrella-like.

(I was wrong - I went for a jelly-fish)

Tell that to Georgi Markov.

I got jabbed with a fecking umbrella yesterday. No Bulgarians involved, just a clewsless Frenchie who didn't notice or apologise. I gave her the evil eye, but her clothes didn't disintegrate. (I didn't think of charging like an outraged lizard.) Guess I need to practice?

Startling one of these lizards can be very startling for you in return. They usually give out a loud hiss and rear upwards, as well as raising their frill (which just snaps out instantly).

The scene in Jurassic Park where the overweight computer guy gets attacked by the small frilled dinosaurs does show the threat behaviour of these things - though "threat" behaviour is all it is; they won't normally attack if you back off.

I recall going to the zoo as a young lad and seeing one of these charge at me. it was amazing.

That's Australia's version of Smokey (the bear). It's native habitat is littered with signs that read "we like our lizards frilled, not grilled". The aboriginals would disagree; they like their monitor lizards grilled.

The scene in Jurassic Park where the overweight computer guy gets attacked by the small frilled dinosaurs does show the threat behaviour of these things - though "threat" behaviour is all it is; they won't normally attack if you back off.

http://www.youtube.com/watch?v=JxNhLFJz6iM

cute!

Love it! When it’s running it is fierce and comical at the same time - and effective. If one charged at me, I would definitely back off.

I can't believe you've violated the privacy rights of the frilled lizard. Watching the video has made me complicit in the violation and totally ruined my day.

That sucker hauls ass. His speed alone was somewhat startling.

I caught a frill-neck while at Uni in Queensland. Not that it involved a lot of cleverness on my part because after I started chasing him he climbed a tree to escape me - but sadly (for him) the tree was a sapling only three feet high and when he got to the top he had nowhere to go; I just grabbed him and took him around to show the overseas students before releasing him.

Unfortunately they weren't as impressed as I'd expected them to be.

I'm intrigued by the thought of how this rapid two-legged gait evolved, from a four legged ancestral gait. Studying these lizards could perhap help us to understand how bipedal dinosaurs, and hence birds, got their start. Kangaroo hopping (and jumping jerboa etc) presumably evolved from the cantering or galloping gait common among mammals.

I wonder whether some lizards run so fast on four legs that the front end 'takes off'. I imagine that the habit might have evolved from one or a few enterprising or adventurous individuals learning the new skill. Then natural selection came along afterwards and favoured those individuals that learned the skill fastest. Eventually, after many generations, they 'learned' it so fast that it didn't seem like learning at all (sometimes called the Baldwin Effect). I have no idea whether that is right in the case of bipedal lizards, and would love to find out.

Prof Dawkins,

one of our commenters posted this a cpl days ago, and didnt get an answer, if youre still around, would you care to comment on it?

A question regarding pretty birds...

As you all know, I'm Australian. And one thing Australia has is a lot of vibrant and beautiful birds. I can understand how sexual selection can lead to, say, males evolving elaborate traits and behaviours in order to win females. Where I'm having trouble in my understanding is where there is little or no (discernable) sexual dimorphism and both members of the species are incredibly vibrant. For example: rainbow lorikeets, eastern rosellas, king parrots.

In terms of trying to fit these birds into my understanding of evolution, I see one potential explanation: While females may select males who are more elaborate, the phenotypic expressions of those genes expresses itself in both species in a similar manner.

"I suddenly remembered my Charlemagne"

JC

Prof. Dawkins

Exactly what I thought on seeing that as well - with a little personal experience to add.

What went through my mind watching that little guy run was "That is not terribly unlike me trying to take off in the (Piper) Cub!"

Fascinating to watch.

JC

@Madscientist:
"Aboriginals" = adjective
"Aborigines" = noun.
Now lad, write it out 100 times before sunrise in letters 30' high, or I'll cut your...

We have lots of these locally, they spend a lot of time in trees and can climb a strong cyclone fence as well. Possibly this contributed to their bipedalism by strengthening their backs or hind legs. One of my vivid memories is when a lizard challenged the bus I was driving, it lost.

And to be a complete wowser, you should call the locals 'Aboriginal people' or 'Indigenous Australians' if you don't know their tribal group. Aborigines has too many connotations. And goanna done on the fire is delicious.

Rohrschach #14:

There are three explanations I know of, and you have already mentioned one of them, i.e. that bright females are merely so because of sexual selection acting on males, with no contrary selection acting on females.

But female birds can be subject to sexual selection too, if there's any component of male choice in the breeding system. Considering that most birds practice social monogamy, there is indeed a cost to males of picking a particular mate, who may in fact be the mother of all or nearly all his offspring. And so he would like clues to mate quality, just as a female would.

Finally, many bird species do have brighter males, but your eyes aren't good enough to distinguish them. Male and female budgerigars may look identical to you, but in the near ultraviolet, which the birds can see but you can't, males are much flashier.

That is the most hilarious video I have ever seen. I was literally laughing out loud.

I wonder whether some lizards run so fast on four legs that the front end 'takes off'.

There is, of course, a literature on this subject.
e.g.: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1693243/

Good videos at Bruce Jayne's lab site:
http://www.artsci.uc.edu/collegedepts/biology/fac_staff/jayne/videos.as…

I miss the voice of Alexander Scourby. Thanks for finding a clip (and a hilarious one at that) with his narration.

Depends on how big and toothy the umbrella might be, I'd guess.

And on how big you are.

Glen D
http://tinyurl.com/mxaa3p

Bipedal running is very common in the Australian agamid clade, but only a few species practice bipedal walking and it is reported to be quite common in the frilly. So I guess it's not just a 'spandrel' in this case (cf. the paper in Sven's first link at #21), but actually something that needs explaining in terms of function. For a social but not colonial animal that is both predator and prey of other vertebrates, with a feeding system (characterising agamids and iguanians generally) based on visual detection and pursuit of moving prey, some advantages of an elevated POV are pretty obvious.

Living where I do, I probably should know a lot more about frillies, but I hardly ever see them. Much more familiar with Lophognathus and 'Physignathus', which do bipedal running but are much less umbrella-like...

"I suddenly remembered my Charlemagne"

JC

Damn you. It's impossible to think of a pop culture reference on Pharyngula and not be scooped.

Sili - I refreshed 3 times and found it difficult to believe that had NOT yet been referenced :-) - it is an exceeding rare day that I would get it first.

I haven't even yet been ripped to shreds with notes that, of course, there is no reliable source that indicates he ever said that....

JC

... Charlemagne that is, not Connery. Lots of proof for that.

JC

The scene in Jurassic Park where the overweight computer guy gets attacked by the small frilled dinosaurs does show the threat behaviour of these things

Uh, that "small" dinosaur was actually the largest predator of it's time, growing up to 6 meters (20ft) long. There really is no reason why a Dilophosaurus would've needed such an elaborate threat display. Or venom for that matter. Whoever is responsible for the abomination in Jurassic Park failed biology forever.

No bones about it, if I saw that thing running at me with its frills spread out, I'd start screaming like a child and running for my life.

Then again, I'm a coward. Little creatures and bugs scare me to death for some reason.

This little guy would sit very quietly on a branch, blending in, but throw in some crickets and he went into party mode. He was awesome to watch in action. There was a baby alligator in an enclosure behind me, but all he did was float and stare at me.

Then again, I'm a coward. Little creatures and bugs scare me to death for some reason.

I hate, hate, hate slugs and snails.

Beat that.

one of our commenters posted this a cpl days ago, and didnt get an answer - Rorschach

Wrong! There were at least two, of which mine was one (handicap effect). Can't be fagged to find it now, but it's somewhere in the previous incarnation of the endless thred.

I hate, hate, hate slugs and snails.Beat that.

Um, if you really really don't like them, instead of beating them (to death?), just walk around them. Or, excepting endangered species, chuck 'em in a bucket of biodegradable-soapy water (or salt, but you cannot then compost that).

Now, if they flew through the air and had lasers mounted on their eyestalks, I could see wearing a tinfoil hat and carry a cricket (or baseball) bat.

I wonder how well the frill acts as a sail, lifting up their front end and allowing the thing to run on two legs so long.

@JC #16: You use your legs to propel the Piper Cub to take-off speed? I've got to see that one; Fred Flintstone would be envious.

MadScientist - no, but it only feels like that would help, if it could be done.

No - it wasn't a SuperCub.

JC

I haven't seen one of these in the flesh since I moved to the city, but I used to see them now and then when I was in high school.

Sclerophanax @28:

There really is no reason why a Dilophosaurus would've needed such an elaborate threat display.<\blockquote>

Other Dilophosaurus?

[I don't think they had frills either, I just think that maybe failure to see a reason for something isn't the same as there not being one...]

With the frill up, the dark spots look like eyes and the shading make it look like something with a snout heading for you. Rising up adds to the effect by putting the "head" at a more plausible height.

You can imagine it starting as an "I'm bigger than you think" display and an aggressive lunge and gradually getting more elaborate and aimed higher.

Yeah, even our tiny lizards want to eat you!

(Ok, maybe just frighten you a little bit)

Another niece story (maybe I'll post nothing but niece stories here, seems appropriate.) My niece loves slugs. She collects them by the dozens. I asked her "aren't they slimy?" She said, "of course, they're slugs." (With an implied "dummy".) She was 4 or 5 at the time, visiting from Australia (they're weird down there), and my mother's yard was positively infested with slugs. She collects skinks, too.