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More on Selective Trout...

Rising trout
a rising trout

I guess it is impossible to prioritize the various "skills" associated with a successful encounter with a truly selective trout as every situation is a little different. So I will try to follow the process I recall going through over the years.

A good place to start is with a question..."Why and how do trout become selective feeders"? Just because you cannot catch a particular fish does not mean it is necessarily "selective". There could be a dozen reasons why you cannot hook a given fish...selectivity is just one of them. I have fished in at least a hundred different rivers, streams and lakes for trout and this experience has taught me that trout in some waters are never selective and in other rivers they may become selective in certain situations such as a heavy hatch and, occasionally, they seem to be selective all the time. So why is this?

I thought about this for a long time but was never convinced I really knew. One day a couple of years ago, I happened across a post on If you are not aware of this forum, you probably should be if you are reading this. I strongly suggest you join (free). The thread was titled "Selectivity - why and how do trout become selective feeders" and author went by the moniker "silver creek". As it turns out, his real name is Henry Kanemoto and he is a retired physician and his best friend is Gary Borger. Regardless, silver creek's post really spelled it out in a reasoned and well explained way.

He laid out four "principles" that answer the question "Why and how do trout become selective feeders"? Those principles are: (1) The first rule is that any behavior is population based (2) The second rule is that selectivity is a survival mechanism and is not based on intelligence (3) The third rule is that selectivity can only occur in fertile watersheds (4) The fourth rule is that larger fish must become more selective than smaller fish if they are to survive. Some of these may not make much sense so you will need to go read the article/post for yourself to fully understand these four principles.

As you read this and other articles on selective trout or trout behavior, we are not talking about every trout in the river...we are talking in general terms. In every biological group there are always exceptions to a "rule" or variations in a certain behavior.

So, there you are, ready to cast to a selective trout. What are the things you need to consider?

1. What are they eating? (mayflies, caddisflies, etc.)

2. What stage of the insect are they eating? (dun, spinner, emerger, nymph, etc.)

3. Which fly will best imitate their food choice?

4. What will be the best presentation? (from above, below or other "angle")

Many of these questions can be answered by close observation of the fish but there is more. See my article on "bank sitting". Ok, let's take these one at a time.

1. What are they eating? (mayflies, caddisflies, etc.)

This is the easiest question to answer because it should be fairly obvious from just looking. If you do not know the difference between a mayfly, caddisfly and a stonefly, you will most probably not understand any of what follows. You can get a quick education by visiting the entomology section of our site. With few exceptions, they will be eating whatever is most prevalent at the time.

2. What stage of the insect are they eating? (dun, spinner, emerger, nymph, etc.)

Again, a basic understanding of the life cycle(s) of the most common aquatic insects is very helpful here. Mayflies have three stages that are important to fly fishers, . They are the NymphSubimago or dun and Imago or spinner. The dun and the spinner are adult (winged) stages. The life cycle of a caddisfly is somewhat different than that of a mayfly. Caddisflies undergo complete metamorphosis. Their life cycle includes three stages important to the fly fisher – larva, pupa and adult. This link will provide you with a very good idea of the three stages that are important to fly fishers. Caddis Fly Info and Life Cycle by I am not including stoneflies here as they tend to be much less important in this discussion.

Often, you cannot determine which stage of these insects are being taken by a trout by simply looking at bugs. Fly fishermen who have significant experience with selective trout will get their biggest clue from closely observing the way the trout actually takes an insect and the resulting "riseform" or disturbance they leave on the surface of the water. In 1976, author Vincent Marinaro wrote what became a very popular book titled "In the Ring of the Rise". Much of the book...all 184 pages, is dedicated to determining what stage of these aquatic insects a trout is taking based upon the riseform of the trout. In 1978, Ernest Schwiebert  published his two volume book "Trout". Contained in the over 1700 pages, Schwiebert describes approximately twenty (20) different riseforms. Again, I will not rewrite what has already been well written by someone else with great qualifications. In this article from Fly Fisherman Magazine, Tom Rosenbauer's piece titled "Understanding Trout Rise Forms" provides a very good discussion and it offers several photos and images to describe the various common riseforms.

One final word and I will move on. When you see an especially large and "splashy" rise, it is often the result of a fish taking a larger insect like a grasshopper or cicada. I have also noticed that when trout are taking caddisflies as opposed to mayflies, their rises are considerably more "splashy". This is because caddisflies tend to rise to the surface and fly away almost instantly whereas mayflies need more time on the surface to dry their wings before taking flight. The trout know this so they are in a hurry. Their rises are not so subtle when feeding on emerging caddisflies.

3. Which fly will best imitate their food choice?

So, you have now decided which insect and which stage of the insect the trout are eating. Your job is not yet complete! You now start looking through your fly boxes for just the right fly to "match the hatch". If you are like me, you carry hundreds of my case, hundreds of just mayflies. 

For those of you that have been fly fishing for trout for a while, You probably know what comes next. It is the age old question..."What is most important when trying to match the hatch...size, color, silhouette/proportion, how it rides on the surface, etc. "

I sure wish I could answer that question for both of us. The best I can do is to reorder them. I strongly believe from having been schooled by selective trout for every bit of forty years that #1 is size, #2 is silhouette/proportion, #3 would be how the fly rides on the water high (dun) or low (spinner) or in the surface film (emerger/cripple) and color is dead last. With regard to size, if you have to choose between two different fly sizes, I will always choose the smaller fly first. I also believe that most small dry flies have too much bulk in the body and prefer my small flies to be very sparse. I do think that the "shade" of a color can be more important than the color itself. If you do not know the difference between color and shade, click here...


I put "how the fly rides on the water" pretty high on my list because I have learned when and how to fish mayfly emergers/cripples. If the lower portion of the fly does not penetrate the surface film it cannot be completely effective. I always carry a small pair of sharp scissors so I can trim hackle or shorten tails to make the fly ride as low as possible.

4. What will be the best presentation? (from above, below or other "angle")

There can be little doubt that the presentation of the fly to a truly selective trout is the final part of the equation and it is often the most difficult. 

There should be a lot of thought before you decide to cast that "perfect" fly to the trout. Again, there is much to consider. It is my opinion and that of many other experienced fly fishermen that your very best chance of hooking that trout is with your first cast. In order to make that cast the best it can be, you need to consider numerous things. In no particular order are variable currents between you and your target, wind direction and strength, your position in relation to the fish, distance to the fish, position of the fish relative to rocks, logs, etc.

The first comment I will make is to stay out of the water as much as you can. I can recount too many situations where I spent valuable fishing time going through the "process" outlined above only to spook the fish within a step or two of entering the water. Sound, especially accidently kicking a rock or even the grinding noise as you wade across a gravel bottom will alert a wary trout of your presence. That said, if you did not need to get in the water, the numerous wader manufacturers would have no market. Assuming you have to get in the water, go slow, pick up your feet and unless you are almost directly behind the fish, keep a low profile.

There are so many variables when you talk about "presentation" that they are difficult to list. In my experiences, I think variable currents and wind are the most problematic aside from just not being a proficient fly caster. Regardless of the conditions, the whole point is to deliver the fly into the trout's field of vision as naturally as you can. At this point, biggest problem here is "drag"

Your Position

The first question I usually ask myself is "Am I better off casting from above or below?" I am most often inclined to cast down to the trout from an angle. Being directly above a fish is often problematic as you can easily stir up mud or other debris from the bottom and it will float right over the fish and it may well spook. Cast is usually a little easier as it is much easier to get your fly into the trout's feeding "window" before he sees the leader or fly line. This is always a good time to use a "reach cast". This is basically a traditional overhead cast and a mend in a single motion. 

However, one of the easiest ways to keep drag to an absolute minimum is to position yourself below the rising fish and cast upstream. There is an approximately 30 degree blind spot directly behind a trout. Be aware that this angle is quite variable because as the trout feeds, it is often moving/turning from side to side and each lateral movement has the potential to expose you. So always keep the lowest profile possible. If you find yourself almost directly below the fish, it may be time to use the curve cast

I have provided a few links to a couple "specialty" casts just above. If you are interested in learning about many others, click here...

Other Considerations

I list these in no particular order as they vary depending on the situation.

*Consider your leader and tippet - see that your leader and tippet are straight (stretch if necessary), check for wind knots periodically, is the length appropriate (usually, longer is better). Tippet size is always a somewhat difficult decision for me. I want it to be as small in diameter as possible without feeling I have to over play the fish to land it. I almost always start with 5X and go down from there if I know I am getting goods drifts over the fish. 

*As I have mentioned above, eliminating drag is paramount. Often, it is easy to see drag and hopefully correct it by mending or changing your position. However, you should always be considering "micro drag". This is drag that is not readily apparent because because it is so minimal. Here is a great short video on micro drag by our friends at Orvis.

*Tippet material has, in recent years become a serious topic of discussion as fluorocarbon have dramatically improved. Because the tippet is always going to be in the trout's field of vision when he approaches your fly, it is a topic when you discuss presentation. Here is a great article that discusses tippet/leader materials from the good folks at Flylords Magazine click here...

Underwater World of Trout Part Three | Trout Vision by Wendell "Ozzie" Ozefovich and The New Fly Fisher 

Note: this is a long video but will tell you more about a trout's vision than you ever guessed possible.

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