'Triggers'

[Silver Creek]

Here are two other points in the discussion of "triggers."

A trigger that has not been mentioned under behavior is the "acoustic footprint/signature" of the fly. Sight is not the only sense that predator fish use to locate their prey. The trout's lateral line is extremely sensitive to changes in pressure waves. This is an anatomical adaptation that allows a trout to find a location in the stream with the least flow resistance so it can shelter itself from the current. This same lateral line is used by the fish to locate prey. Flies that displace water when retrieved send out acoustic pressure waves that attract predatory trout. The blades of a Mepps spinner does the same thing by sending pressure waves that indicate that the spinner is a live organism.

Just as motion can suggest that something is alive, so do acoustic pressure waves. Just as the acoustic pressure waves of a wading fisherman can cause a fish to flee without even seeing the angler, so can the pressure waves of struggling minnow or fly attract a predatory fish to investigate. This is how fish detect flies in discolored water of at night. A trigger need not be visual!

http://www.garyborger.com/2009/12/09...tic-footprint/

A streamer fly that has a bulky "collar" of material at the head is specifically designed to create an "acoustic trigger". A Gary Borger Collared Leech is specifically designed to create and acoustic trigger.




There also can be what Gary Borger calls "super triggers," referred to by Byron in his post. These are enhanced properties of the fly over the natural that go beyond just meeting the search criteria. They are specifically designed to attract fish by enhancing the property of the natural.

What do I mean by "enhancing" the search criteria? An example is the reddish/orange spinner fished at dusk. At dusk the ambient light is the red/orange glow of the sun at sunset. Even spinners that are not naturally red or orange look red/orange in the golden light of sunset. A sherry colored spinner will catch more fish at sunset than the natural color of the spinner because of the enhanced reddish orange color of the artificial.

Gary Borger told me of a discussion he had with John Goddard of The Trout and The Fly, A New Approach, which has an extensive discussion on trout vision, pp 59 - 105. John had wondered why the Sherry Spinner which has a reddish orange tint would catch more fish than flies of the natural color. The puzzle was solved when John went under water and looked at the naturals which had a reddish glow due to the reddish light at sunset. The flat spinner wings on the water had an orange glow.

The red/orange light at sunset and dusk causes the naturals at this time of day to take on an orange reddish tint. Flies of this color fished at or near dusk will catch more fish than flies that are identical the color of the naturals. An orange spinner fished at sunset will "match the hatch" no matter what the color of the natural.

Matching the hatch is a concept based on selective feeding. Selectivity is a survival mechanism that trout have developed to gain the most food with the least effort because they feed efficiently and do not waste energy trying items that are "not food". They simply cannot help themselves.

Normally color is a minor search criteria, but when feeding on spinners with translucent wings, the sherry color of sunset causes the flat spinner wings to glow that distinct color.

The concept of accentuating a key feature of the natural that attracts the the fish's attention to the artificial vs the natural is called a "super trigger". The sherry spinner wings are a super trigger. It causes the artificial to stand out amongst the naturals and the fish seem to preferentially choose the artificial from amongst the naturals.