Posted on 05/30/2006 5:28:58 AM PDT by S0122017
27 May 2006 From New Scientist Print Edition. Subscribe and get 4 free issues. John McCrone
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LOOKING more like a flake of bark than a spider, Portia labiata stops to have a think. Portia is a jumping spider that makes a living by eating other spiders - a risky business at the best of times. Luckily Portia has brains.
Right now it needs them. Portia, no bigger than a thumbnail, is perched on a branch with its beady eyes trained on a Scytodes pallida, another spider that specialises in eating other spiders. Scytodes is a spitting spider. It can squirt zig-zag jets of poison-coated silk from its mouth glands that would snare Portia in the blink of an eye.
They are like two high-rolling gamblers about to bet all their chips on a single throw of the dice. Fortunately for Portia, Scytodes doesn't know it is being watched. Spitting spiders have weak eyes and Scytodes is content to lurk in its web in the cup of a curled leaf in the forests of the Philippine island of Luzon, until some unwitting passer-by stumbles in. Portia, on the other hand, has excellent eyesight, with spatial acuity better than a cat or a pigeon. From a safe distance about half a metre away, Portia sits scanning Scytodes.
First it needs to know whether Scytodes is carrying a sac in its fangs. This is how Scytodes protects its eggs. And to do any spitting, it has to drop them first. If the spider had eggs, Portia would mount a frontal assault. It would creep to the edge of the web and gently tickle the threads, luring Scytodes into the open for the pounce.
On this occasion there is no egg sac. Worse, there is no way Portia can execute its regular plan B - crawl around the web and jump Scytodes from behind. So perched on its branch, Portia begins to plot. For a good quarter of an hour it scans the undergrowth, its tiny brain working out possible pathways across boulders and branches. The retinas of its two principal eyes have only a few thousand photoreceptors, compared to the 200 million or so in a human eye. But Portia can swivel these tiny eyes across the scene in a systematic fashion, patiently building up an image. Eventually Portia makes up its mind and disappears from sight. A couple of hours later, the silent assassin is back, dropping down onto Scytodes on a silk dragline attached to a rocky overhang, like something out of Mission: Impossible. Once again, Portia's guile wins the day.
Back in the lab, the story has a different ending. "Oh, that wasn't meant to happen!" cries Simon Pollard, a spider researcher at University of Canterbury in Christchurch, New Zealand. A Portia in a little plastic flask has just been dispatched by a white-tailed spider that was supposed to be its supper. "I guess a bottle isn't a very complex environment, so Portia doesn't really get the advantage of its greater intelligence," says Pollard, more than a little aggrieved.
The Portia genus, which is found across Africa, Australia and Asia and makes up about 20 of the 5000 known species of jumping spider, is fast becoming something of a celebrity in animal cognition research. Honeybees, with their intricate social behaviour and waggle dance, have long been considered smarter than the average bug. But neuroscientists have generally been dismissive of creepy-crawlies. Their nervous systems were supposed to be capable of no more than hard-wired reflexes, and certainly no one would talk in terms of thinking, planning, trial-and-error learning, attention span or - shudder - consciousness. Insects and spiders could never have anything approaching a mind. Yet Portia does stuff that doesn't fit with the idea of invertebrates as automatons.
Watching Portia crouched in its flask, it is easy to understand why its abilities have been overlooked for so long. Ragged, hairy and drab, it wouldn't attract a second glance. Yet since researchers woke up to the fact that Portia had exceptional eyesight and unusually flexible behaviour, the surprises have just kept on coming.
One of Portia's principal skills is luring other spiders from the safety of their webs. Portia will pluck out rhythms at the edge of a web to mimic a trapped insect or a hostile intruder. If it has encountered the resident spider before, it sometimes knows what rhythm to use - a remarkable ability in itself. If it hasn't, Portia will try out various patterns by trial and error. It can tickle the web lightly, strum it vigorously, bob up and down as if on a trampoline - whatever it takes to persuade its target to move into the right position for an attack. Sometimes the foe will be two to three times Portia's size. The trick is then to arouse its curiosity without provoking a full-blooded rush.
Duane Harland, another researcher at the Canterbury lab, says this web plucking reveals cognitive skills that were thought to be beyond such a small creature. He contrasts Portia with web invaders such as the white-tail, which are all brawn, no brains.
"The white-tail can pluck, but only in a programmed, stereotyped, way. It doesn't bother with tactics, or experimenting, or looking to see which way the other spider is facing. It just charges in and overpowers its prey with its size. Portia is a really weedy little spider and has to spend ages planning a careful attack. But its eyesight and trial-and-error approach means it can tackle any sort of web spider it comes across, even ones it has never met before," says Harland.
While Portia's deception skills are impressive, what is most remarkable is its ability to plot a path to its victim. For an animal operating on instinct, out of sight is usually out of mind. Yet Portia can take several hours to get into the right spot, even if that means losing sight of its prey for long periods.
This capacity has been tested with mazes in the lab, both at Canterbury and at the University of Sussex, UK. In a typical experiment, researchers create a choice of two paths with coat-hanger wire (see Diagram). The set-up simulates a pair of branches growing out of the forest floor and crossing over each other in a confusing way. At the end of each wire is an identical prey-holding dish. Into one the experimenters place a dead spider, spray-coated to remove odour cues. Then they release a hungry Portia onto the top of a tall, wooden dowel that commands a view across the whole apparatus. To get to the bait, the spider has to work out which branch to take, climb down the dowel and onto the floor and then climb up the correct wire. Once off the platform, though, it can no longer see the prey and has to rely on memory.
This would be a tall order even for a rat or monkey. Yet more often than not, Portia succeeds - though it takes its time. Portia sits on the viewing platform for up to an hour, twisting to and fro as it appears to track its eyes across the possible routes. Sometimes it gives up. But once it has a plan, it clambers down and heads for one of the wires, even if this means walking past the other.
Harland says it seems that Portia knows where it wants to go and ignores distractions along the way. This is strengthened by the fact that on trials where Portia starts climbing up the wrong wire, it often gives up as soon as it reaches the first bend - even though it still cannot see the bait. It is as if Portia knows where it should be and can tell straight away when it has made a mistake.
In another experiment, Robert Jackson, head of Canterbury's spider lab, placed Portias on an island in the middle of a water-filled tray. The shore was too far to reach in a single leap, so Portia had to decide whether to jump some of the way and swim the rest, or swim all the way. Once in the water the researchers made waves that either hindered its progress - favouring the jump/swim strategy, or helped it, which favours swimming all the way. Jackson found that spiders would remember what happened on their first trial and either use the same strategy again or switch it, depending on whether it had been successful. Again this seems a rather dynamic, unprogrammed response for such a small brain.
Recent experiments by behavioural ecologist Daiqin Li at the National University of Singapore have demonstrated yet more startling cognitive abilities. He has found that after Portia makes a kill, it finds it easier to spot prey of the same species and becomes less attuned to other types of prey. This looks very much like selective attention; Li controversially describes it as the formation of a "search image", meaning that Portia has some kind of mental picture of its prey. Many psychologists would baulk at granting such abilities to cats or even chimps, never mind spiders.
“Many psychologists would baulk at granting such abilities to cats or even chimps, never mind spiders”How clever? Crazy talk, obviously. There just isn't room in Portia's head for anything approaching an inner mental life. The human brain has some 100 billion brain cells, and a mouse has around 70 million. Harland says no one has done a precise count on Portia but it is reckoned to have about 600,000 neurons, putting it midway between the housefly's 250,000 and the honeybee's one million.
So what do the researchers conclude? Does Portia have some inkling of a mind? Or can every behaviour be explained away in terms of instinctive responses? Harland says many of Portia's cognitive abilities may eventually be explained by the design of its eyes - specifically by their inbuilt limitations.
All jumping spiders have excellent vision and Portia's is 10 times better than the average, making it sharper than that of most mammals. Being so small, though, there is a trade-off: Portia can only focus on one view at a time. It has to build up a picture of the world by scanning a scene point by point, as if peering through a keyhole.
Harland thinks that understanding the serial nature of the spider's vision makes it easier to imagine how prey recognition and other processes could be controlled by hard-wired programs. When Portia is looking for an egg sac, for example, it wouldn't need to deal with the scene as a visual whole. Instead it could check a template, ticking off critical features in a sequence of fixations. Perhaps the less the eye sees with each fixation the better.
The human brain, on the other hand, has to cope with a flood of information, and much of the work lies in deciding what to ignore. The laser-like focus of Portia's eyes might do much of this filtering by default. So what seems like intelligent decision-making could really be an evolved selective blindness.
But this doesn't necessarily make Portia any less remarkable. Harland says there is still a disconcerting plasticity in its behaviour. His next step in understanding Portia's cognitive abilities will be to use eye-tracking equipment to find out exactly how Portia scans the world as it is pondering its choices.
There is a lot to learn. As Jackson points out, only a few years ago no one would have believed a spider could show such clever behaviour. Today we are having to ask whether creepy-crawlies are a jump closer to being mental beings. Look into the eyes of a spider and who is to say it is not, in some sense, looking back?
John McCrone is a writer based in Christchurch, New Zealand
From issue 2553 of New Scientist magazine, 27 May 2006, page 37
smartest spider ping
Have the scientists dropped a black obelisk into a jar full of them yet?
I've seen some amazing stuff from various animals. No one believes me when I say the frogs in my little pond watch for me to show up with a fly. I'm glad I finally got a pic of the Anole eating from my fingers. I have more shots showing it actually clinging to my hand, and eating, but the focus is not good. Reptiles are not incapable of learning, and they are not just preprogrammed automatons.
I've watched the alligators at the St. Augustine gator farm wake up, and congregate, just before the scheduled feeding demonstrations, with no visual clues, they know what time it is. No one gives any signal, the gators just know it is 1:50 P.M. Why not a thinking spider?
The birds and animals I photograph aren't tame, but many of them seem to know me as an individual. I'm not a PETA groupie, I hunted actively for 50 years, but there are still a lot of things we know damned little about.
I'll size the other Anole pics, and post them, the little critter will crawl all over me. It would come in the house, but my cat would kill it.
I noticed intelligent behaviour among my rabbits!
I used to have three, each separated from the other with their own den and fenced-in outside area covered with a lid against rain, bordering eachother.
One night it was very windy, and we heard the lids clapping a few times. Next morning it was discovered the rabbits had switched their areas.
The adult male got to the female (got her pregnant too)
and the juvenile male got in the space of the adult male.
The wind alone wasn't enough to lift the lids, and we observed how the rabbits managed to do what they did later that day when they attempted to repeat the switch:
They stand up on their hindlegs and grasp the lid (part fence) with their frontpaws and jump up. The lid is lifted and the wind can now get a grip. The lids are lifted for a few seconds and in that time they jump in eachothers area's.
Ofcourse for this to work they would all have to lift and jump simultaneously, which is what they managed to do after a few 'testruns' (the clapping we heard).
The weird thing is, I have absolutely never noticed them trying that before, why they would try something like that just when there is enough wind to make it succeed is a mystery.
Scary right?
I was hoping to buy some of these spiders and let them loose in my garden. Maybe keep em in an empty aquarium and catch some spiders to put with it.
I totally dig jumping spiders bump
I smacked a yellowfly, and started lowering it to the Anole. He jumped up, clung to my fingers, and took the fly. This fly was flattened, the Anole still recognized it as food. 
Down the hatch. 
This time, he waited for me to bring the fly to him. He is leaning forward to meet my fingers. 
The Anole has caught flies on the side of my head, and on the view screen on a camera. He just started, I made no effort to "train" him. Go figure! It is difficult to get the camera at the proper distance for a macro shot when you hold it out away from you, you just hope it comes close.
neat your own pet dinosaur :)
Who needs The Discovery Channel when you have FR.
Cool stuff.
I may as well admit I ain't totally housebroke, LOL, my last girlfriend freaked out over the neighborhood gators.
She will be happier back in Noojoisy!
Now a pic of your Kumodo would be REALLY neat!
So cool!
I sure don't live on Sesame Street!
PETA will be arriving shortly to emancipate 'Old Crusty'.
Thanks for the pic.
http://magazine.uchicago.edu/0112/research/invest-dino.html
(( ping ))
Interesting natural history, some nice photos of reptiles.
Interesting stuff.
I love that forum! It is funny. Haha, the things I read... ofcourse there are nutties here too. *ahem* Anyway..
There was a guy on DU that claimed that he had proof that
the government ochestrated 9/11 and that it wasn't caused by crashing planes! The proof was that the type of passenger planes that where supposed to be hijacked don't fly above a particular speed for safety reasons. The planes that crashed into the twin towers supposedly went faster, ergo, they couldn't have been those passenger planes! Think about that one for a moment :)
Luckily even his fellow DU's didn't buy it.
The comic comes from a page where the ability of the planes to knock down the towers (an event witnessed literally by millions, actually billions) is derided. What a bunch of maroons. It's part of the literal and public merging of the skinhead/KKK/PPB with the so-called left.
News? I didn't think there was ever anything new in the conspiracy community. ;')
By Drake Andrews
Weekly World News
LONDON-Members of the British Royal Family are blood-drinking satanists who regularly participate in black magic-rituals that include the sacrifice of children.
Those are among the shocking revelations by researcher and author David Icke in his blockbuster book The Biggest Secret.
The ghastly practices are all part of the chilling dark side of the world's best known royal family, and are an integral element of their efforts to build up devastating magical powers used to control millions of people around the world, according to the study.
"There used to be an elite circle who took part in ritual orgies at Buckingham Palace," according to Christine Fitzgerald, a former close British royalty confidante, who is quoted in the devasting report.
And an American woman, Arizona Wilder, reportedly admitted she formerly officiated at satanic rituals in Glamis Castle in Scotland, and at Balmoral, the Queen's residence in Scotland.
"She said that during the sacrificial rituals the Queen wears a cloak of gold favric inlaid with rubies and black onyx, the one-time professional soccer player turned investigative journalist wrote.
"The Queen and Charles have their own ritual goblets, inlaid with precious stones.."
Children sacrificed in the bloodcurdling ceremonies at Glamis Castle are almost all under 5 years old," Miss Wilder reported.
Children are reportedly choice sacrifices at the obscene rites. But pregnant women-who are often deliberately impregnated by the Satanists themselves-are the most potent offerings of all, according to Icke's sources.
During a video-taped interview, Miss Wilder had these things to say about the obscene satanic activities of these members of the Royal Family:
.The Queen Mum-"I have seen her sacrifice people." The Queen Mum-the most popular member of the Royal Family-was reputedly present when two teenage boys were sacrificed.
.Queen Elizabeth-"I have seen her sacrifice people and eat their flesh and drink their blood."
.Prince Charles-"I have seen him sacrifice children. there is a lot of rivalry between them for who gets to eat what part of the body and absorb the victim's last breath and steal their soul."
.Prince Andrew-he was reportedly observed by the former black magic priestess, participating in the evil rites.
Prince Phillip, the Queen's consort, along with the couple's daughter, Princess Anne, were also observed at controversial rituals but were not seen taking active roles in them, the woman is quoted as saying.
_____________________________________________________________ http://www.rumormillnews.com/cgi-bin/archive.cgi?read=6341
I am sure some will question the source of this article, but have you ever looked into the eyes of the royal family? Have you ever wondered about this royal rule considering the destruction that England is undergoing?
With no chin, it must be tough for them to keep the blood from dripping all over the shirt. ;')
which is why they wear ritual clothing. Didn't you read the article? ;)
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