Wednesday, July 2, 2014

Not A Carp

This is turning into a summer spent pursuing large carp. But with little success since returning home from our Finger Lakes trip. This weekend DP and I visited an old haunt where he at least has caught sizeable fish. We blanked and were doubly put to shame by the variety and quantity of fish my daughters nonchalantly reeled in.
The only bit of excitement to our rods came when DP snared one of those prehistoric snappers. Forcibly delegated to commit the surgery necessary to remove hook from tail I did so. Apprehensively.

Tuesday, June 10, 2014

Random Quotes XXXVI.


I'm reading a collection of E. B. White's essays at the moment and in this version the inside sleeve has the following quote taken form the citation that accompanied his winning the Gold Medal for Essays and Criticism from the American Academy of Arts and Letters.


"If we are remembered as a civilized era, I think it will be partly because of E. B. White. The historians of the future will decide that a writer of such grace and control could not have been produced by a generation wholly lacking in such qualities, and we will shine by reflection in his gentle light.
Of all the gifts he has given us in his apparently careless essays, the best gift is himself. He has permitted us to meet a man who is both cheerful and wise, the owner of an uncommon sense lit by laughter. When he writes of large subjects he does not make them larger and windier that they are, and when he writes of small things they are never insignificant. He is, in fact, a civilized human being - an order of man that has always been distinguished for its rarity."


I'm only a third of the way through but the quote sums up what comes across. A fantastically smooth, thoughtful writer of hugely engaging and beautifully crafted essays. I shall take a piece form one titled "Here is New York" for the next Random Quotes.

Thursday, June 5, 2014

Very clever grouper.

Reading about fish cognition always reminds me of a paper that came out in 2006 about grouper and moray eels in the Red Sea. Hunting associations between species has been well documented particularly where “followers” accompany a nuclear species to take advantage of their activities - lions and jackals, wolves and ravens, buffalo and cattle egret and in a fishing world, rays and permits. Grouper and moray eels are often the objects of other follower fish too but these two species have also been shown to hunt cooperatively.

Roving Coral Grouper


Eight years ago a study2 was published that showed roving coral grouper in the Red Sea recruited giant moray eels to go hunting with them. To initiate the cooperative hunt the grouper swim up close to a resting eel and perform a stereotypical horizontal body “shimmy” to “ask” it to come along.

Giant Moray Eel


For a grouper asking a moray eel to go hunting is a good strategy. Grouper are diurnal hunters of the open water and so a sensible course of action for any hunted prey fish would be to dive into a rocky outcrop or coral head and hide whenever threatened by this large predator. Groupers that ask eels to hunt do so to cover this particular eventuality. The eel can squeeze into all the crevices that a grouper can’t get into and may flush the prey fish back out into the open water.

Napolean Wrasse


The benefits are less obvious to the eel because, being mainly nocturnal, it is being asked to hunt when it would otherwise prefer not to. Nevertheless, moray eels don’t have to flush the prey fish out but can catch and eat it themselves if they manage to trap it in its hiding place. And the data seems to show that moray’s hunting with grouper catch more fish in a set time period than when they hunt alone.

Now this interspecific accord, this recruitment of one species to hunt cooperatively by another different species is interesting and rather cool in its own right. But the behavior goes one further3.

Coral trout


These Red Sea grouper have been shown not only to ask a moray eel to hunt with them at the beginning but also to direct an eels attention to the specific place a prey fish is hiding after it has been chased there by the grouper. And not only eels. Napoleon wrasse, a large fish that bludgeons its way into coral and can suck prey out of hidey-holes, are also recuited. More recently, observations on Australia’s Great Barrier Reef have shown that the Coral Trout, actually another species of grouper, recruit octopus to come and do the same job moray eels do many leagues away.

Having chased a prey fish into hiding the grouper modifies its horizontal shimmy, the one it uses to ask another fish to come hunting, by doing the shimmy while performing a headstand. The headstand is directed at the specific place the prey disappeared. Grouper only do this if they can actually see a possible partner in crime, either one they were already hunting with that didn’t notice where the prey fish escaped, or directed at a local bystander the grouper can see. If the partner or bystander doesn’t quite get it, looks in the wrong place or swims in the wrong direction or, heaven forbid, loses interest, the grouper may swim to within a few inches of the potential helper, do the horizontal shimmy to reinforce the fact that they are meant to be hunting (duuh!) and then go back to the bolt hole and repeat the headstand shimmy.

You can see bits of the behaviour in this short video.


I was wondering whether the fish actually go and look for a partner to recruit if they were hunting alone and couldn’t see a suitable candidate in the vicinity after the had cornered a prey fish. But they don’t. I suppose this is because it would result in the “oh bugger” reaction when they arrived back, partner in tow, to find the prey had scarpered long ago. How embarrassing - “look it was here a minute ago…”. No, but what they do do is wait for a potential helper to happen by, wait over twenty minutes at times, and then go into their headstand.

This is all fascinating stuff and the underlying point here is that the sort of signals these grouper have been observed to make are very rare in the animal world. Animals that perform ‘referential gestures’, as they are known, intentional signals directed at a recipient with the aim of influencing the recipients behavior in a particular way, belong to an exclusive club. Or so it has been claimed. Primates have been known to gesture to the handlers and to a lesser extent to each other in the wild when it comes to showing exactly where they would like to be scratched. Ravens have been claimed to make referential gestures to each other too as have Australian magpies that adopt a particular body posture when they see a wedge-tailed eagle.

But I’m a little confused at the wider definitions of referential gestures and cognitive ability. For example, dogs have been trained to make particular postures when they identify the presence of game - a sitting bird or rabbit or the like. This posture, being ‘on point’ as I seem to remember it being called, must also be a referential gesture as it fulfills those requirements outlined above. And that makes me think of my post on buffalo democracy. In the post I highlighted a study that showed how buffalo vote on where to find food after they have had a rest. Each buffalo stands up, adopts a specific posture facing the direction they think the herd should go in to find food after they have finished resting. This would appear to be an intentional signal aimed at influencing other herd members. So why would this not be a referential gesture?

It’s a sticking point (at least for me) because such behaviours are often claimed to be evidence of higher cognitive ability, of moving some animals intelligence more on a par with non-human primates. But if the behaviour is actually quite widespread those kind of claims look more like wishful thinking.

That is not to diminish the recruitment behaviour shown by the groupers and their various partners. But it may only remind us that animals can adapt in very complex ways and evolve, as the second paper noted below clearly states, cognitive solutions according to their ecological needs. Grouper stand on their heads, buffalos vote and dogs point but it doesn’t mean they have the cognitive ability of primates. Especially not the dogs.




2. Bshary, R et al. (2006) Interspecific communication and coordinated hunting between groupers and giant moray eels in the Red Sea. PLoS Biology, 4(12): e431. doi: 10.1371/journal.pbio.0040431.
3. Vail, A. L. et al. Referential gestures in fish collaborative hunting. Nature Communications, 4:1765 doi: 10.1038/ncomms2781.

Tuesday, June 3, 2014

Clever cod.

Here is one of those bits of research1 that leave me scratching my head a little. Not in frustration at any omission, lack of clarity or any other normal concern I hasten to add. No the study is simple and well done. The head scratching is to try and imagine the sequence the animal goes through to end up at the observations reported.

See there are these cod living in a tank, a pool really, like those swimming pools you see in back yards, raised above the ground, hexagonal, octagonal, multi-tagonal things, generally quite small, one push off the side and your banging your head on t’other before you can say rats, a couple of you sit around, arms draped over the wall after a curry night out and you have a jacuzzi. The cod's pool is a little like that only smaller.


These cod have been trained to feed themselves. There is a string with a bead on the end that dangles in the water. Cod takes bead in its mouth, jerks on the end and a set number of fish pellets are delivered into a drop zone a little away from the string and bead. This is fairly standard. Fish are naturally inquisitive, just like any other animal, and getting them to feed themselves by pulling on a string or pushing a lever has been standard practice for some time. Introduced to the tank the fish will test the pulley system over time eventually getting to the point where they learn that if they take the bead into their mouths and pull it with enough pressure food will get delivered.

Each of the cod in the the tank - nine or ten of them - has a tag stuck in their back for identification. This tag sticks up a little. Swimming round the small tank one fish’s tag inevitably gets caught in the bead. The fish doesn’t like it, can’t twist itself off for a few seconds and swims in a panicked fashion until the bead detaches. It is clearly an event that prompts an aversive response by the fish.

Given this response what happens next is somewhat surprising. Three fish learn to swim up to the bead, carefully hook their tags onto it, give a little twist to pull on the string and release the food, and then with just the right sort of wriggle quickly release the bead and swim over to the drop zone and scoff the fallen pellets.

The researchers didn’t set up the study to look for this. They were interested in the use of self-feeders for other reasons. But, to collect the data they videoed the tanks so that they could later analyse the film for the response of the fish to the feeder - how many pulls, which fish does what and all that kind of stuff. Their videos are available here (click the "Supplimentary Material (1)" tag underneath the abstract). The first one shows a standard self-feeding event with the cod taking the bead on the end of the string into its mouth pulling and then swimming rapidly over to the drop zone a little to its right. The second video shows one of the cod accidentally getting its tag hooked in the bead and swimming away trying, unsuccessfully to start with, to get off. The third video shows a cod sidling up to the bead, carefully hooking itself up, wriggling off after pulling and again going to the drop zone to get the pellets it has released. Now these are research videos so the production standards are low. The biologists already know the set up well and can quickly interpret what is going on. For us it may take two or three views to fully get the picture but after that it is really quite clear. They provide a handy little schematic too.


The second video, where the cod hooks itself accidentally, clearly shows aversive behaviour. The fish swims away, is pulled up by the string, has to right itself and try again to slip the bead off the tag. It is the cognitive leap from this aversive reaction to the positive seeking of being hooked up (and the skill displayed in doing so) that I find quite something. How did they get round that first negative experience to turn it to their own ends?

The study authors explain that by hooking up to the bead they can get to the deposited pellets faster than if they activate the string-bead by mouth. They also note that not all fish learnt this trick but for those that did using the tag rather than their mouth became the preferred food activation technique, exclusively so in one fish. Three fish learnt the technique and it seems that one fish may have done so originally and this was then copied by the others. Such copying behaviour is often described as the cultural transmission of information. The authors also point out that the process shows “innovation” and because it was carried out with what is effectively an artificial limb (cod do not use other parts of their body - fins for example- to manipulate objects) this novel behaviour fulfills the requirement for demonstrating tool use.

All this is fine, at least as far as initial descriptions and explanations of the behaviour go. But it still seems quite a step to go from the bad experience of accidental hook-up to the positive and preferred experience of deliberate entanglement. It is possible that in the close confines of the tank, in an environment that promotes experimentation for reward (there are few other stimuli to get in the way) this is not quite as much of a leap as it would initially seem. But still, it does seem that the cod have remarkable cognitive chutzpah to get the tag hook-up sequence sorted out.



1. Millot, S. et al. (2014) Innovative behavior in fish: Atlantic cod can learn to use an external tag to manipulate a self-feeder. Animal Cognition, 17, 779-785.

Sunday, June 1, 2014

Boundless

The other day I was looking for information on Betelgeuse. Not for anything particularly dramatic other than I wanted to make an oblique reference to Ford Prefect and the fact that he is an alien. An alien who happens to be from a small planet somewhere in the vicinity of Betelgeuse. While meandering I came across these images. They're fab. The largest planet in the first picture, Earth, becomes the smallest planet in the next picture and then the largest, Jupiter now, becomes the smallest in the next panel. And so on.


It is not so much the image itself (I’ve split it apart going down the page - the original full image is at the bottom), but the dawning realisation of how vast some of these heavenly bodies actually are. Vast really isn’t a good word. It means “huge” or “exceedingly great” of course but it also means “boundless” and you suddenly start to get a glimpse, just a mere plucking at the corner of your mind, what boundless, boundless, might actually be.


It brings to mind those times when someone who knows about and is articulate enough actually explains what a light year is (about six trillion miles), and what a voyage covering light years might actually mean. Except that’s not really true. Trying to get a grip on traveling for light years is still beyond my comprehension. Six trillion? What the fuck is six trillion? Clearly I’m not one who can grasp such concepts.


These images do a similar job. Jupiter, who (and it is a who of course, big daddy God and all that) although our giantest of gas giants (ha!) becomes a carbuncle on the bum of Sirius but at least is still there to be seen and thought about. It is possible to nod at the progression, to keep up with the increasing size of these bodies but only as long as you keep only two of the panels in the sequence in mind.


But trying leaping around. Try to go back to Jupiter from panel 3, and then bring its image and scale back, in your mind, and compare it to say Acturus here in panel four. It is just about possible, I try keeping the scale of the planet in comparison to Sirius alive and then and then bring that mental image into the next panel.


But one more panel forward it all becomes ga-ga, a bit foamy at the mouth, brain hurty. Betelgeuse, appropriately a ‘red supergiant’, doesn’t just swallow Jupiter, it is as if Jupiter, now so small in comparison, doesn’t really exist.


Why this invariably bothers me I don't really know. One might say that the scales could be reversed and I could start thinking about cells and molecules and atoms. But it doesn't work for diminution. Big, and the comprehension of really, truly, gigantically, enormously BIG does. So, whenever confronted by these changes of scale all I can do is boggle at them, as Arthur Dent might. But not in the way one would to a velvet paisley-coloured Chesterfield sofa, not with the remotest hint of any intelligence. No.






This full image can be found on Wikipedia’s “Betelgeuse” page.


Friday, May 30, 2014

Letters to Donald - VII


Dear Donald,

I am in receipt of yours of the 15th inst. Yes, sorry about that. I honestly didn’t know there would be a problem mixing ammonia and wool.

as for the other matter I can see it might be frustrating but really, if you are one of those types who insist on putting dots above a letter in your name, a funny squiggle below a c or liberally distribute accents across vowels on a whim what do you expect? You can’t really think a country that can’t spell colour, or mechanise, or haemolymph, or, well manage any normal sort of spelling (not to mention the zed thing), is actually going to get its finger out of the very dark crevice it seems to be in at the moment and spell your name correctly you have another thought coming.

Talking of names and thinking of your forthcoming event you may not have known have been told that I wanted to call our first born Stanley. Given the sort of names you mention as being popular nowadays I am sure she would have grown up completely at ease with her moniker and I would have had the continuing delight of saying “ay up Stan, what’s to do,” and dreaming of her playing for Doncaster Rovers when she’s a bit older. That idea got quashed fairly quickly by her of the Niblets. She ended up with some very ordinary name. Mary. Margret. Zelda. Something or other anyway, not that it matters as I never have to call her by name. A stern look at the Portcullis and the job is done.

The second was a bit more of a problem. With Stanley not washing it took a bit more of a squeeze on the old creative juices to get past the Old Castle’s defences. I pitched Hannah knowing it would be refused out of suspicion for whatever my first choice happened to be and then I’d steal in with Geoffrey, also expecting it to be refused, whereupon I’d whip out Bernhard - a real winner. But bugger me Donald, if she didn’t go and say yes that’s the one to the first choice. And the double whammy is she then argued that as I got my choice I get none for he second name. It isn’t Hannah Edwin Eustace Percival Tarquin Eccles but something much more prosaic and of the common unwashed hoard. I forget what exactly.

Anyway getting the spelling of your name right on the documents allowing you an extended stay is the least of your worries at the moment. Your better two quarters came down for a visit while you were off pleasuring yourself with drums and she seems to have put on rather a lot of weight. And come the event I don’t think naming it Roger Federer II is going to wash somehow.

Yours in denial
Willi

PS I listened to Nutbush City Limits the other day. Mr Turner isn’t Swiss is he?

Tuesday, May 27, 2014

A Carp

Well, that went better than expected.

DP wiv a firty. Oh yes.