Though I have absolutely no scientific evidence for it, I think fish might use their mouths as we use our hands - to feel stuff.
You're in very good company with that idea. Gary LaFontaine wrote that he suspected fish in riffles are just as selective as fish in slow pools, but they select things by tasting and spitting them out. Unless there's a hook involved. :) I'm not completely sold on the idea but I'm sure there's some truth to it and it would be interesting to study more carefully.
I often try to develop patterns (and many others do this as well, perhaps without really stopping to think about why) that capture the attention and curiosity of the fish, flies that do things just a little differently from other naturals and artificials they see on a daily basis.
I think that works well for both opportunistic fish (for obvious reasons) and selective fish. This fits with some more ideas I learned from reading LaFontaine (would somebody
please bring that guy back to life and send him to this forum??), that selective fish aren't selective to every detail of their target. They may want just size, or just color, or just movement, or just some conspicuous body part, or just a certain light pattern in the surface film, or all of these, or any combination. LaFontaine suggested that, as long as your fly has the features the fish is looking for, it's a sufficient imitation, even if it has some other stark differences. So you could match what the fish wants but embellish your fly so it's easier to detect, and your fly will be "better than the real thing." I think this idea makes a lot of sense, but there are lots of complications with putting it into practice.
Why do some fish expend so much energy on inaccurate rises, flipping two feet out of the water to slap haphazardly at dries?
Trout can be puzzling for sure, but there are always explanations. Maybe when a trout does that it's misjudging what's necessary to catch the prey. Maybe that kind of jumping is a way to show impress / intimidate competitors encroaching on a feeding spot. Or maybe that trout has fed so successfully in the last couple days that it has more energy than it's physiologically capable of channeling into growth, and it spends the excess by "playing," which is really practice for future behavior that may be necessary... jumping after dragonflies or something.
I can't say which one of these (if any) is right. But short-term periods of inefficiency are not inconsistent with trout being long-term efficiency maximizers. Remember I'm thinking about mechanisms that maximize efficiency over the
very long term. Trout (like all animals) do many inefficient things for many different reasons on a day-by-day basis. But evolution will still select in favor of a behavior which consistently improves long-term energy gain.
Which is basically that one can make this sport as simple or as complicated as they want. In my experience, the more complicated things are, the less reliable they become...
That's true, but it depends how you define complexity. Many times in science, the least complex ideas are the hardest ones to explain. Theoretical physics is a great example. It's very simple: a handful of small, fundamental equations govern every physical interaction in the Universe, and they are the most reliable things we know. But understanding exactly what those simple rules are and how they scale up to the things we directly observe is very, very, very, very, very, very difficult. Somebody could suggest an alternative idea much easier to understand, like that the Earth is held up on the backs of an infinite stack of turtles, but that idea doesn't have the virtuous kind of simplicity. It doesn't logically lead to answers to all the questions it's supposed to address... it just puts a smile on the face of people who don't ask a lot of questions.
I think virtuous simplicity is about trying to get the most explanatory power from the smallest set of starting ideas. So that's what I aim for with trout behavior. I want to find the simplest set of instincts that would logically lead to the behaviors we're trying to explain. That's a sound method even if it requires a lot of complicated deduction to get from my starting point to my final explanations.
That their work was the first to take a purely scientific approach to the feeding habits of trout, I think, has been lost on a lot of folks since it's initial publication; hence the word "selective", which by definition would mean that a cognitive choice is made, being overused and/or misused. To this day I'm still amazed by the number of anglers that use the word "selective" and when asked about the book they say, "What book?" Personally, I think your concept of "targeting" (not fixation which, again, implies a cognitive process) is precisely what Swisher and Richards talk about.
It's hard to decide which term to use. "Selective" was the first word used to describe the phenomenon we're talking about, so it's the most likely to get everybody on the same page. But if taken literally it does clearly imply a more active cognitive choice than what's really going on. I think "fixated" and "targeting" both have cognitive implications, but they're both minimal, exactly the sort of simple thoughts we might reasonably ascribe to fish. I guess "targeting" is the most precise word to describe this feeding behavior, but fixated may be closer to the mark, since it also implies a reduction in attention given to non-targets and maybe even to other factors such as competitors and predators. That's a whole other can of worms.
Anyway, when
I say "selective," you can be sure I'm talking about the targeting behavior you found described by Swisher & Richards. I'm just using the most common terminology even though I agree there are better word choices out there.
Lastly, (finally) my whole point is that an angler who is "frustrated" during a hatch should look first to the obvious (the basics) before discounting his/hers lack of success to "selectivity". Did I just "plow" into the river and start flogging away? Where is the sun in relation to my quary and myself? What is the water clarity and my leader length?
Definitely good advice! As much as I like to think about selectivity because it's such an interesting ecological puzzle, I completely agree that it's given much more credit than it's due as a reason why people fail to catch fish.
Is there anyway we can get paid for this continuing discussion; this is more fun than work.
That's what I'm doing! Not this particular discussion (unless you count revenue from the site, I guess), but for my masters I'm plugging away at a similarly interesting puzzle involving the tradeoffs juvenile chinook salmon make between food and safety.