Match the Hatch... Fact or Fiction?

[NJFred]

[quote author=AaronJasper link=topic=3253.msg24403#msg24403 date=1245459651]
Ok you're right... There is no discussing this....
[/quote]

Apologies... if I come across as "not discussing this" that's not it, I'm just an ardent defender of selectivity in trout. Sorry if I put you or others off an any manner.

[LopatNympher]

[quote author=NJFred link=topic=3253.msg24415#msg24415 date=1245512111]
Wanted to chat about trout as opportunists.

First what they eat (and have been conditioned to.. which is a great word someone above has used) dramatically depends upon their system. In a rich system like the Delaware trout can grow and prosper by only eating one "pattern" (over a period of time) that they recognize as food ignoring other "patterns" which are food. The Pattern they see and recognize is plentiful enough for them to feed exclusively on this. They don't need waste energy rising to something which looks different and may not be food. They don't risk getting picked off by a predator for no reason. Now take a trout in an insect poor system. This fish has to be much more opportunistic. They must rise to all sorts of stuff to be able to maintain body mass. They have to take more risk and waste more energy rising to something that doesn't look like food. In fact they may have an extended view of what is food which does rule out some things that aren't food and rules in things which look kind of like food (attractor flies).

So for me... rich systems naturally bring on selectivity neccessitating match the hatch for the fisherman to be most successful.
[/quote]I tend to agree with you here but I do not believe a trout that is feeding exclusively on a certain mayfly is going to pass up something like a fat juicy cranefly larva that drifts past its nose or even within a few feet of it.

[AaronJasper]

The Henry's Fork might be the ultimate match the hatch stream on the planet.

[NJFred]

[quote author=LopatNympher link=topic=3253.msg24418#msg24418 date=1245519002]
[quote author=NJFred link=topic=3253.msg24415#msg24415 date=1245512111]
[/quote]I tend to agree with you here but I do not believe a trout that is feeding exclusively on a certain mayfly is going to pass up something like a fat juicy cranefly larva that drifts past its nose or even within a few feet of it.
[/quote]
I can tell you on the Delaware I see fish show no interest in what you and I would describe as a juicy morsel almost every trip. They are rising to one particular mayfly at a particular stage sometimes even focusing strictly upon cripples and still borns even when there are more plentiful duns on the water and every now and then bigger mayflys.

The only logical explanation to this behavior is selectivity. Further I even suspect that at the moment they don't recognize the other flys as food during when this behavior occurs. Their little pea brains allow them to recognize only the stuff they are eating as food. If they saw the other flys as food why wouldn't they eat them at least now and then?

As far as the more plentiful duns on the water that they are not eating... Seen it with Paraleps and hendriksons, seen it many times with Pseudos and other hatches. Often this occurs when a hatch is waning and a new one beginning. They are dialed in to the old hatch and haven't gotten into the new one.

[Soft-hackle]

Hi Fred, Everyone,
I see it as taking the more vulnerable insect. It's more like the lion chasing down a hurt or wounded animal. Now, this may tune them into patterns that replicate that vulnerable insect or stage of an insect, but I don't think it is preferential as the word "selectivity" might imply. It's instinct. The trout are given a stimulus, a fly that's easy pickings, a cripple, emerger or spinner. The stimulus triggers their predatory instinct, and they react.

Mark

[NJFred]

[quote author=Soft-hackle link=topic=3253.msg24427#msg24427 date=1245527398]
Hi Fred, Everyone,
I see it as taking the more vulnerable insect. It's more like the lion chasing down a hurt or wounded animal. Now, this may tune them into patterns that replicate that vulnerable insect or stage of an insect, but I don't think it is preferential as the word "selectivity" might imply. It's instinct. The trout are given a stimulus, a fly that's easy pickings, a cripple, emerger or spinner. The stimulus triggers their predatory instinct, and they react.

Mark
[/quote]

Mark I do think vulnerability is part of the equation. However, I don't think trout see a fly and think boy is that vulnerable and then eat it. I think bugs which are vulnerable are in the surface film longer and hence the fish start to recognize them and go after them. For example fish a spinner to a fish eating caddis pupae in the film during the day and they are likely to not eat the spinner even though they are more vulnerable. Why?, the fish are keyed into the caddis pupae look, size cooler, and probably movement. They don't recognize the spinner as food let alone vulnerable food.

BTW... I have pitched spinners to a lot of fish eating something else... most often they don't eat it even though we know it's vulnerable.

I think it plays a role but it's not something that is thought about in any detailed fashion by the trout.

[Soft-hackle]

Fred,
It'd take me a while to type out Mr. Wyatt's idea of why trout take flies. I find his ideas very, very interesting. They are somewhat in harmony with your own, but not exactly. If you have not read Bob's wonderful book - Trout Hunting, The Pursuit of Happiness, I highly recommend to those that want to know more, but be entertained as well. In addition, there are a number of great patterns within. If you manage to get a copy, I would definitely pay attention to the section on Fly Design.

I will present this quote, however, which I think you will find interesting.

" Where the food supply is restricted to a single type, or for short periods during one phase of a sustained hatch, trout may develop narrowly constrained feeding habits, but the exclusively selective trout is a rare beast at the extreme end of the spectrum of fly fishing problems. It's a mistake to think that all trout are picky eaters. "

Mark

[Silver Creek]

[quote author=BlackLabel link=topic=3253.msg24408#msg24408 date=1245463352]
I not going to argue with anyone but what I've been told is trout actually aren't very smart and that is what makes them difficult to catch. I mean think about it you guys are talking about them passing up drakes for sulphers, thats not very smart. Lots of other fish out there would go for the biggest meal they could but not trout.
[/quote]

Trout have a low IQ, if that is a measure of intelligence. How do you measure fish IQ? The same way you do for other animals I presume, by seeing if they can remember a sequence of tasks to get food pellets. The longer a sequence they can remember, the higher the IQ.

Another test is to remember a maze that gets increasingly complex to find food. The maze gets more and more complex, until the animal can no loger remember the series of turns to reach the food.

There are two authors that refer to Trout IQ. My friend Gary Borger says that it has been measured at about 6. See: http://www.flyfishersofvirginia.org/garyborger.htm

"Gary Borger scoffs at the notion of anglers having to outsmart fish. The IQ of a brown trout is around 6, he said. "Fish are not people," and they don't think like people. So while the average fly fisherman frets about tippet diameters, hook sizes, matching the hatch and presenting the fly artfully, the average trout basically ponders one simple question. Food, or not food?"

Ian Colin James says it is about 3. See: http://www.flyfishersrepublic.com/ta...the-fly/part2/

".....according to some research from the USA, the common carp, with an IQ of 6, is twice as smart as a trout...."

And : http://www3.sympatico.ca/ianjames/ask7.html

"...You need to remember that carp are in fact smarter then trout. Carp have an IQ of six while trout only have an IQ of three...."

Whether it is 6 or 3, trout are stupid creatures. They don't think, they react.

[Silver Creek]

It seems to me that matching the hatch is really a discussion about selectivity. If that is true, then we need to know why and how how selectivity develops.

Selectivity occurs only in situations where there is abundant food. If the fish live in a stream where food is scarce, they will feed opportunistically. They cannot be selective to just a single food source because there is never a large or sustained hatch to become selective. So selective feeding occurs only in nutrient rich environments.

Selectivity is the most efficient method of feeding. An organism can only survive if the energy it gets from food is greater than the energy it expends to catch and eat the food. Selectivity then is a biologic necessary method that optimizes survival. It is a biologic adaptation that gives the organism that uses it a survival advantage. That is the reason that the fish feed selectively. They cannot help themselves from becoming selective feeders.

Another biological cause of selectivity is the size and age of the fish. As fish grow older and larger, their energy (calorie) requirements become relatively greater. A large fish requires more energy to chase food and yet gains fewer calories per body weight when it eats the food. Because larger fish expend relatively greater energy to catch food, but receives relatively less energy when it captures food; it must feed effectively if it is to survive. What is crucial then is not the total number of calories in a food item, it is the ratio of the calories spent vs the calories consumed per body weight.

For large fish, selectivity is more important as a survival strategy than for smaller fish. That is why we see smaller fish chasing food and our flies but rarely do large fish chase a fly unless it is a large fly that promises a large reward in calories.

Once a fish feeds selectively, it cannot help itself from feeding on our fly, if the fly meets the criteria for food.

How then does a fish become selectivity? Well, they don't do it through intelligence. Trout cannot reason. What trout can do is sample; they sample what they think is food. If the item is food and it is abundant enough, the trout will feed on it often enough that the visual pattern of the food eventually becomes imprinted. Then the fish then begins to search for this food pattern exclusively and ignores most other items that could also be food. If the food is very abundant, the fish will begin to both narrow the area it searches ( the fish feeds only on food that is in a narrow "feeding" lane) and the fish will develop a feeding rhythm. The fish mechanically moves up and down, taking the food item that happens to be in its feeding window.

The fish does not reason, it takes whatever is in the window that meets its search pattern. It is all automatic and the fish cannot help itself from taking our fly if it meets the search pattern, and it is in the right place (feeding lane) at the right time (rhythm).

The question then becomes, what are the fishes search criteria (triggers)? Everyone seems to agree that size, shape, behavior and color are search criteria. We know this, not because of positive evidence, but because when the fly does not meet all or most of these criteria, the fish refuses to take the pattern when it is in the right place at the right time.

When discussing selectivity, or selective feeding, we must realize that we are discussing a biologic system. In any biologic system there is variation in the population and there will be a variation in behavior. So although the discussion above treats a population as a single unit of identical behavior, the reality is that there will be a variance in both behavior and timing, so that what we find is similar to a bell curve distribution. Although the majority of fish may be feeding on a given stage of emergence, some fish may be still feeding on an earlier stage or may have progressed to a later stage.

Combine this variation in behavior with overlapping or simultaneous multiple hatches, and the possibilities become confounding to the angler who is trying to "match the hatch".

This confounding behavior, however, is not a conscious attempt by the fish to fool the angler. It is just the result of an efficient feeding method superimposed on a fish population with biological variance.

Why do some fish take other forms of food when most are selective? Again it is biological variance. Fish are not automatons. There is room for variance, and in fact, if there was no reported variance in a biologic system we would suspect that the data was flawed or manufactured. It would be too good to believe.

So a fish breaking out of selectivity can mean either biologic variance in a large fish or a juvenile fish that has no need to feed as selectively to optimize its caloric intake.

[Soft-hackle]

The explanation can't get much better than that.

Mark