Behavior Modificiaton

Behavior Modificiaton

Jason Borger | Tuesday, 27 September 2016

As a kid I was practically obsessed with the six-pound brown trout on page 156 of A.J. McClane’s epic New Standard Fishing Encyclopedia. I knew that my angling life could never be complete unless such a fish graced the end of my line. As it turned out, attaining completeness would require some behavior modification.


That modification came in the summer of my tenth year, as my father and I were fishing a deep, cliff-side pool on Wyoming’s Green River. I was casting a big Strip Leech on a floating line and catching nothing. My father, on the other hand, was doing a good impression of a fish-exercising machine. Eventually taking pity, my father forced me to switch to my sink-tip line, a shorter leader, and a couple of bulbous split shot. He told me to cast and mend just above the pool’s lip, to allow the fly and sink-tip to go deep, and to work the fly back with an active, but measured retrieve.

A few casts and retrieves later, something slammed the leech and made a charge for the tail of the pool. My father grabbed me and we gave chase, hoping that my tippet would hold. Just above the next set of rapids—where I would surely lose whatever was attached to my line—my father made a daring, diving scoop. And there it was: the page 156 brown in all of its glory. My angling life had been made (temporarily) complete, thanks to some behavior modification.

When it comes to behavior modification, there are a number of factors that can come into play, including the materials used in the fly itself. The famed Clouser Minnow is perhaps the best-known example of a fly that uses weight to great advantage. Little more than a hair-wing coupled with dumbbell eyes, Clousers go down now, and when retrieved with a rhythm they can create a fish-enticing jigging motion. The caveat with heavy flies such as Clousers is that they are just that: heavy. In areas of complex bottom structure, you need to keep the fly moving. If the bottom can be navigated safely, however, a heavy fly can sometimes be “walked” along—particularly in flowing waters—using a combination of well-timed rod lifts and the natural tumbling effect of the current. Joe Humphreys has a thorough description of this “walking” tactic in his 1981Trout Tactics book.

Conversely, flies that are built with little or no weight do not enjoy such deep-diving benefits. Careful line manipulation and/or smart use of currents, however, can work wonders. When fishing Russia’s Kola Peninsula a few years back, the most successful Atlantic salmon fly that I used was Mauri’s Magic Muddler, a thinly dressed, non-weighted, marabou-based design. The slight build of the fly really came into its own one day on the Aquarium Pool of the Sidorovka. I used the lee of a mid-stream boulder to position the fly line at mid-length, while the fly slid around in the main current, ultimately hovering a few inches under the surface in the eye of the pool. Although the fly only held position for a few seconds, it was enough time for a very acrobatic Atlantic to take notice. The light fly really helped to make the whole thing work.

Adding weight to the leader can further alter the dynamics of the system. I typically use split shot (or sometimes putty), and typically place the weight anywhere from the eye of the hook to a point about six to a foot in front of the hook. With putty it is possible to place the weight directly on the head of the fly (a bit of post-construction fly design).

Those who put in serious hours on lakes may want to take a weighting lesson or two from the stillwater anglers of the UK. One tactic is to combine a buoyant fly (foam-headed patterns are good choices) with a fast-sinking line. The line dives deep while the fly wants to go for the surface. A slow, pulsing retrieve makes the fly work like an anti-jig, crawling along above the bottom and rising during a pause.

Having a working knowledge of behavior modification is not the end-all to making your fly effective, but it can go a long way toward greater fly-fishing success—and perhaps a page-156 brown of your own.