Many fly fishermen leave the stream frustrated thinking “what was that trout taking?”.  Learning how to “read” rising fish forms is important for distinguishing what trout are feeding on. It will help the dry fly angler to understand whether a trout is feeding on an emerger, dun, or spinner. Here are a few ways to tell what stage of a mayfly trout are feeding upon.


This article is part of a series of FLY FISHING TACTICS

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Trout rising to emergers
Trout rising to emergers

Emerger Rise Forms

When a trout is feeding on an emerger, the first thing to remember is that most emergers are drifting by just subsurface. Trout usually do not show their head when feeding upon them. A trout showing its dorsal fin then tail followed by the fish pushing down creating a bulge, boil, or splashy take is a good indication it is feeding on an emerger.

These takes can be both subtle or aggressive. Some emergers come down in large numbers drifting close to the surface such as Hendricksons and Sulphurs. These emergers are usually fed upon in a rhythmic fashion. Emergers such as March Browns which come down in fewer numbers and quickly rise to the surface are often taken in an aggressive manor.

Typical Dun Rise Forms

Larger duns, when taken, are characterized by an obvious head- dorsal-tail rise. The word obvious is used because trout need to poke their head out farther to get their mouth over the larger size fly.

Trout taking dun dry fly
Trout taking dun dry fly

Sometimes with smaller duns, it is difficult to tell whether a trout is taking a dun or spinner. A fish showing its head, dorsal, then tail is usually taking a dun, but not always. They do also take spinners with a head, dorsal, and tail rise, but it is very often more subtle. Paying attention to the water and seeing what insects are coming down in the largest numbers will often distinguish what a trout is taking.

Spinner Rises

Spinners are one of the most productive flies on large rivers with good hatches. Because spinners are dead and lay flat on the water they present an easy meal for trout, which in most cases, they cannot resist.

Trout rising to take spinners
Trout rising to take spinners

A trout feeding on spinners will take head, dorsal, then tail, but at other times will just dimple taking the vulnerable meal. The rise is incredibly subtle, and the size of the fish beneath the rise is often surprisingly big.

Large wild trout love spinners, as they can expend the least amount of energy. A trout taking spinners will feed similar to a fish taking duns. Trial and era is best when your still not quite sure. Just remember to look for the more subtle rise usually found in the tail of a pool or flat water.

Fly Fishing During a Spinner Fall

Image standing riverside at night and hearing a Glubpish…  A sound similar to dropping a 5 pound cobble stone in the water from an inch above the water.  You ask yourself was that a trout or a beaver?  It’s dark so you’re not sure.

In late June when the nights stay above 65 degrees or so a massive hatch occurs in Michigan called the “HEX” and that noise you heard was a big Brown trout losing all daytime inhibitions to gorge itself on a 3-inch mayfly.

The spinner fall can be so thick it’s like big snow flakes covering the water.  Unfortunately, if you fit the hatch during a peak like that, it’s un-fishable.

Trout that have lived quiet lives and fed deep suddenly start looking up…for big bugs.

Learning how to distinguish rising fish forms will increase your dry fly fishing success. Most anglers who have put their time in have an understanding of rising fish forms and can identify what the fish is taking 90% of the time. Watch the fish carefully, and select flies accordingly. Being able to cut a lot of the trial and era out will increase the time you fish with the correct fly.

One More Cast

Learning rise forms is a step toward being a more experienced angler.  Be Observant, Patient and Feel the rhymes of the water.  I know it sounds like something Henry David Thoreau would say.  But maybe he touched on something when he wrote “Many men go fishing all their lives without knowing it is not fish they were after”

Fishing Quote Many Men Go Fishing Henry David Thoreau
Fishing Quote Many Men Go Fishing Henry David Thoreau

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Hi David Humphries Owner of Guide Recommended. I love everything to do with fly fishing. Casting, Tying, YouTube, writing about it and even teaching. I’ve got a FREE video workshop teaching how to dry fly fish at this link How 2 Fly Fish

Hi David Humphries Owner of Guide Recommended. I love everything to do with fly fishing. Casting, Tying, YouTube, writing about it and even teaching. I’ve got a FREE video workshop teaching how to dry fly fish at this link How 2 Fly Fish