One of the fascinating aspects of fly fishing is having conversations with other fly fishers. It has always fascinated me how very different view points can be offered on a given subject. Let's take a look at one particular aspect; selective feeding behavior.
This feeding activity is more so associated with water systems that have a abundance of mayfly hatches, though this is not always the case. Midge and terrestrial falls can also be very significant at times and there are times that sub-surface feeding patterns will also demand a good level of skill to catch fish. There has probably been more work and research done on this particular aspect than any other, and as yet, there is no 100% answer.
You cannot treat fly fishing as a exact science. Let me say that from my standpoint that l am by no means suggesting that all that has been written makes no sense, because much of it does. I would however like you to give a food for thought process in this month's column based on my own observations and of course from having fished many such circumstances that would be classified as selective feeding patterns of behavior.
Take into consideration these facts (1) Man cannot create artificially that which is created by nature. (2) Fish will become conditioned and develop an acute sense of awareness the more they are subjected to fishing pressure. (3) Much emphasis is put upon the actual stage of the emergence that determines when the trout will take the natural, or how they see it at any particular time during the stages of transition.
Factor # 1. No natural organism is attached to a metal hook or a nylon tippet. More to the point, a natural organism by way of its anatomical structure is infinitely superior to any artificial. In so far as its color variation is concerned that too is very much the case. Subtle shades, and at times the transmission and passage of light through and off of the components of the body give effects that are not easily duplicated, if not impossible.
Naturally, innovative fly tiers have striven to deal with that for a few 100 years, in some cases with very ingenious results. The train of thought being that a particular aspect of the natural is what would be highly visible to the fishes eye, and of course there would be a great deal of truth in that assumption. One prime example would be the wings on a emerged dun. In truth if you were to take into consideration such factors as size, overall color tone, and a degree of anatomical resemblance you are well on your way to deceive a fish. But the fish can always call the tune !!
Factor # 2. The human conditioning factor is of course the result of human presence and interference. A wild trout in a natural environment deals with predators such as fish-eating birds, animals like otters and mink, fish and many others that may find fish delightful to eat. If you approach a trout in a natural wild habitat that it does not see humans it will flee. However if human presence becomes a every day occurrence and part of the trout's daily observations it may not flee in terror. In fact l know of places that they will actually swim to ward you as you wade around.
They have figured out that the human form cannot hurt them, but that you will disturb bottom dwelling organisms to the trout's advantage, (food) The primary factor that fly fishers have to deal with is the fishes senses that have become finely tuned to your fly fishing techniques, and that is the main reason why conditioned fish become more difficult to catch, if not nearly impossible in some circumstances.
It is not normal for a trout to behave in such a way. And that factor also applies to many other species of fish. If you have ever fished for wild trout in some way out place they do not see humans hardly at all you will know what l am talking about. The fact that you cannot catch them at that time is related to other reasons.
In order to catch fish that have now developed a greater sense of awareness terminal tackle must also be fine tuned. Fine tippets, tiny flies, and personal concealment are all part of the necessary deception required not to mention the perfect fly fishing presentations. You are not normally going to get away with a mistake.
Such fish have learned lessons, particularly on hard fished catch and release water systems. More to the point they have adapted to a new feeding behavior. A wild trout in its undisturbed natural habitat does not act the same way. Trout are opportunistic feeders and all forms of likely food source will be investigated, digested, or ejected accordingly. The longer a fish lives in a given body of water then so naturally it becomes more so aware of what is good to eat and what is not.
Factor #3. By definition, selective feeding means that either a particular organism is on the menu in preference to any other, or a stage of the life cycle of that organism in question is chosen at that time. For most of you selective feeding activity is a visual one that relates to surface activity. The question that you ponder is what is causing this. Two factors here are species identification and the fishes feeding pattern. Then comes the question of what stage of the emergence should my artificial represent.
First, stage one. If for example the natural is surface visible such as a emerged dun you will see it. You will also see the fish take it. Match the hatch and you should be able to catch the fish! If however you cannot, other factors come into play. One very good quote that l will give you is this. " IT IS NOT WHAT IS ON THE WATER IT IS HOW A FISH SEES IT " and therein lies the secret to success.
Take for example a cross view of a stream. The trout is facing the current as the nymphs or pupa ascend to the surface in a down stream drift. If the trout is at the stream bed then its optical view will be a large one and may allow it to see all transitional stages of the emergence.
If however the fish is at the surface level or just below, it will see a very different picture very much depending on many factors such as available light source, relative angle of the sun, size and color tone of the species, type of species, stage of emergence, surface movement caused by structure, wind, wave and so on. Take into consideration that at any time during a hatch as each individual nymph or pupa travels down stream there will be for each millisecond a difference in the transitional stage.
Therefore, l have never been of the opinion that a fish will select an individual based on the fact that (for example) 50% of the emergence has taken place, and that is the only stage that the fish will eat the natural. A trout does not have the ability to be that accurate in its point of decision. My personal view based on having fished for and watching thousands of fish feed this way in both still and running water is this. It is the visible factor that will determine the trout's feeding pattern.
Visual aspects related to the meniscus, or water's surface. That is below, in , partly out or above it. Accordingly you will need to fish with the correct choice of artificial, and your presentation must also be correct. But relative angle of presentation and correct depth are well more than half way to solving the problem of a selective fish. Of course, if an actual stage of emergence is not taking place, and the subject is say ants or some other terrestrial bug form, then it will be absolutely your artificial and your presentation that would be the deciding factor here.
At a later point in time l will delve into this fascinating aspect of fly fishing . With some solutions that you are probably not aware off. One thought that l will leave you with now is this - Do not let your eyes deceive you! Remember it is how the fish sees it!
Tight Lines for now.