The world's best flyfishing site.

The Urinal Cake Theory
by Bob Wyatt


The older I get, and the longer I keep at it, the more I become convinced that the first and really only important thing you need for good fly fishing is feeding fish. This season down south, I had my nose rubbed in that proposition more times than was necessary. The way it works, by my reckoning, is that a trout's activity is simply wired to its food supply, to the degree that it takes the presence of food to awaken its predatory behaviour. In other words, trout aren't always in a predatory state for much of the time they are switched off. No amount of good tactics, presentation or excellent fly tying is going to make much difference. Despite our homocentric view of things - that what we do is the most important thing happening out there - it's a feeding fish that is going to take the fly.

As self-evident as this may seem, it isn't as obvious or widely accepted as you might think, and I know that this will rile those who believe otherwise. Plenty of anglers insist that by good technique and good flies you can 'work' a fish up. Their interpretation of occasional success reinforces this idea. Carl Mc Neil (Bumcast) has something similar in mind. He reckons that you can stay on a fish until it takes, and there may be something in this because it seems to produce fish for him. George LaBranch famously wrote a book based on his belief that you could create an artificial 'hatch' by repeated casting to a fish. That idea was reheated more recently in that poetic 'shadow casting' nonsense in A River Runs Through It. Well, I'll bet the pink slip for my 4X4 that old George would have shadow-casted himself into a coma for a few days on theWaikaia last January.

The usual situation was like this: Carl and I would sneak up the bank, rod tips down, stopping every few feet to carefully scan the water ahead, trying to make out the transparent grey/brown shape of a trout. And we found them, plenty of them; fish after fish, holding in what appeared to be a perfectly catchable position along the edges of the pools and runs, or out against the shingle bottom. And time after time, we spooked them. If we could manage a successful stalk to within range, we'd try a nymph and they'd just move aside to let it pass. Dries just floated overhead until the fish finally spooked. It was enough to make you weep. Often they just buggered off as soon as we saw them, or they had already buggered before we saw them. They were unbelievably spooky. Now we did notice and remark that the fish that didn't bugger off seemed to be lying rather still out there. No rises and none of that exciting side to side motion of a trout feeding hard on drifting nymphs. These fish were almost all poker straight and still. We came upon quite a few trout lying right up on the edge, sometimes head tucked into the shore. Not the body language of a feeder.

Carl wondered if they were asleep, but we soon found that certainly wasn't the case. Their sensory array was on full alert where danger was concerned, but as far as feeding went it appeared they were definitely switched off. I ventured that we were witnessing exactly that - part of the fish's survival mechanism was working fine, to the degree that even food was spooking them. Certainly any perceived movement on the bank was enough to send them packing. Basically, they were being impossible. Maybe part of their brain was actually asleep - the predatory part - but with another part of their sensory system, the defensive part, on full alert. Many anglers I know would ascribe all sorts of reasons for the fish being so difficult; often with some version of 'selectivity' leading the charge. The idea, I guess, is that the fish were not only waiting for something specific to float their way, they were actually terrified of anything else. This is just an extreme example of the usual conflicted 'selectivity' theory. Sorry, I just don't buy it. These fish were off, or, more accurately, they just weren't switched on.

What was absent from the equation, the switch, was sufficient food to stimulate the predatory readiness for food. There was nothing on the water, and from all appearances nothing drifting below the surface. The early season ephemerid hatches were over, and the next big sushi train, the cicada hatch, was still a week or more away. So, as we know, no predator is going to waste energy hunting for food that isn't there. Better to lie up and wait it out. The trout seemed to be in a semi-conscious state waiting for the next prey cycle in its season. They weren't really asleep; they just weren't catchable. This, I realise, is hard for some anglers to accept, but I'm convinced it's true, although I can hear the indignant arguments already.

All we could do, for the most part, was spook 'em, no matter how carefully we stalked them and made our presentations, I reckon it's because to 'work' a fish up it has to be in a feeding mode, at least to some extent, partially awake to an intermittent food supply. Good fly fishing is a matter of tuning in and fitting our approach to what is actually happening in the environment. We integrate our approach to the natural cycles and rhythms of the prey, like any good predator. I don't think we 'make it happen', despite how much it may appear to be so, and how flattering to our egos. What we do is introduce our imitation bug, or fish or whatever, into the trout's feeding context. This idea has taken shape as a full blown theory. Carl calls it the 'Urinal Cake Theory'. This probably deserves an explanation.

Carl, in a metaphorical mood one night, and well gooned on whisky I might add, outlined the UC theory. To wit; if you stick a urinal cake in a bowl of marshmallows and offer the bowl to a kid, the child will probably try to eat it. The urinal cake might look a bit different, maybe even stands out in terms of size and shape, but the kid has no reason to suspect that anyone would stick a urinal cake in a bowl of marshmallows, or even knows what a urinal cake is. Similarly, a trout has no reason, or the capacity, to think that our fake fly is anything but just another bug. If the trout's food has been intermittent and varied, even better that makes it easy for us, the trout will be ready to take almost anything that doesn't actually scare it. If the food source is abundant, a single type and specific size, and has a particular posture on the water, things sometimes get more difficult a spinner fall for instance. Your fly has to either fit the narrower feeding context or interrupt the established stimulus/response sequence the urinal cake in the marshmallow bowl.

One day, Carl and I worked on several pods of good trout that were keyed to willow grubs dropping from the low hanging branches. These willow grubbers are notoriously tough fish, but the interesting thing was that unlike the fish we had encountered up and down the same river over three days, these fish weren't spooky in the slightest. Elsewhere on the river, the slightest movement or shadow would send trout bolting for cover. We stood on a high bank in full view of these grub feeders and worked on them relentlessly for three hours. We made hundreds of casts to the same fish, while one cast anywhere else that day, no matter how careful, was met with sheer terror. There is no doubt that the fish could see us, after the first few minutes of sneaking up on them and crouching in the weeds, we eventually walked around in the most careless manner, fully upright, waving rods and hooking branches above them. The trout didn't give a hoot, and just kept on feeding. We managed to hook a couple of them too, and even that didn't put them down. This behaviour, as you can imagine, gave rise to some serious theorising over the whisky later.

Those willow grubbers were catchable. The grubs dropping from the willows were a consistent source of food, not much nutrition individually but lots of them. The steady drip feed of grubs is the prefect stimulus for a truly selective feeder, although the fish aren't actually 'selecting' anything. The tiny grubs are the only food on offer in any quantity, and the trout naturally key on them. Anything else, even a perfectly good insect, is not likely to be recognised as food at all.

The feature necessary for what we call selective feeding, or more properly 'limited attention', is a consistent size to an abundant food item. Trout are known to key to the size of abundant prey, and once they are focused it's hard to break into that stimulus/response sequence. It can be done, however, as we proved on the Waikaia, which makes these superabundant prey situations, such as caenis or buzzer hatches, not impossible. What's good for us is that the same limited attention that makes for 'selective' feeding also makes the fish hard to spook. Carl and I also proved that by our antics in full view of those Waikaia fish - for hours. We made some disastrous casts; repeatedly hooked the overhanging willows, several times yanking leaves and even whole branches off the trees, right on top of the trout with a splash. Each time we screwed up a cast we reckoned that would finish it, but the fish would just sink down a few inches and soon resumed feeding.

Well, we caught a couple of those fish. Not on willow grub patterns exactly, but on smallish flies. I found a well-plucked and ginked size 16 Greenwell spider as good as anything. Willow grubs at that stage would be pretty difficult to imitate anyway, maybe requiring a size 24. And they don't look like much, maybe a few twists of sparse cream/olive dubbing and a black head. Trying to imitate these things just leads you down the garden path. Even the relative size of the hook is a problem for realistic imitation. Our biggest problem wasn't fly pattern; it was drag. It was tricky getting a good drift under those willows and the slightest amount of drag would result in the fly being ignored, but whenever I got a drag free float over the fish I would get a response and occasionally a solid take, several of which we missed. Even pricking the trout didn't put them down. It was tough but let me tell you, it was great fishing compared to what was happening just downstream.

A couple of weeks later it was all changed. The tussock grass cicada, the double cheeseburger of New Zealand terrestrials, was on the water and the trout were in full Mac attack mode. Again, you naturally tried to get the fly more or less in the ballpark, size-wise, but the trout's aggressive predatory nature had been fully awakened and anything that even remotely resembled a cicada was taken with abandon. These were the same fish that only weeks before were as skittish as young nuns. Once the cicada showed up I suppose the trout were technically being 'selective' again, but out of pure badness Carl took some real beauties on a huge and horrific foam rubber Chernobyl Ant. Carl, being more reckless in his approach than I am, and operating on what you might call the strong version of the Urinal Cake Theory, reckoned that maybe it resembled three or four cicadas in some kind of perverted mating ritual, basing this idea on the well known midge 'cluster', for which a biggish Griffith's Gnat is sometimes employed. Well, okay, maybe. I stuck to my old standby, a hare's ear D H Sedge, mostly for aesthetic reasons. Tradition has to count for something.

 

Return to whence you came
Return to home page