"Fishing Discoveries" Tutors

Brian Miller

Be vewy vewy quiet, I'm hunting Cutthwoat Twout
Forum Supporter
I've been fly fishing since 1976. When I bought a Tenkara rod in 2017, I found the "Discover Tenkara" channel on YouTube. DT was started by a couple of anglers and guides in Great Britain; freshwater biologist Dr Paul Gaskell & John Pearson. I subscribed to and studied their DT YT channel videos and their free email tutorials for 6 months over the winter and early spring before being able trying it out and was amazed at how well it all worked. Later I purchased some of their "DT Academy" paid tutorials. It has all greatly helped me become (I daresay fairly) successful with a Tenkara rod, and a better angler overall.

They have expanded their scope to encompass western fly, lure, and bait fishing with:
(I'm a fan but receive no incentives from DT or FD to talk about them)
I received an email article today that may help partially explain why I have been (what I believe is) successful using a Tenkara rod and techniques with just a few basic fly patterns (as opposed to lots of gear) that emphasize stealth, casting accuracy with a high rod "fly first" presentation, putting no line on the water to control the fly's drift, and using manipulation to create subtle fly movement if a drag free drift is unproductive:
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reposted here by permission from the author

Fishing Discoveries

Have you heard that saying?
"Well, until they find a talking trout, I guess we'll never know why they take a fly"
On some level it is basically true that there is a limit to how much we understand what controls the things fish do.
The saying still bugs me though...
Underneath it there seems to be a kind of feeling like "You'll never know everything, so why bother trying to understand anything"
It feels too much like a counsel of despair.
Horses Can't Talk Either
"The Horse Whisperer" would have been a much shorter film/book if people had accepted the same logic with horse behaviour...
In the same way, there would also be no such thing as animal behaviour as an area of science (and we wouldn't have the lovely footage of Konrad Lorenz swimming along with his flock of geese following behind).
The trick is to take a more indirect route to trying to understand.
Biology & Fishing
For as long as I can remember I've been interested in things that live in water. My career in freshwater biology has shaped my fishing (and my fishing has shaped my work in biology). These days it's not really possible for me to separate the two things.
Being able to look at a river or a lake and have a gut feeling about how it all fits together and works feels a bit like a fishing super-power.
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Sensing where the fish will be, what they're doing and what the prey species are up to at a glance is both satisfying and a source of confidence.
It's not that I'm saying you need formal scientific training to go out and see these things. Developing that gut feeling is a very practical process of taking a fishing rod along and trying things out.
With that said, having a little bit of knowledge of how people work things out in ecology and behavioural sciences can really accelerate your learning and increase your appreciation of fishing and the natural world...
Zooming Out
At the very broadest level, there's a big advantage in appreciating how time and the environment act together as a filter. It's a filter that keeps any behaviours that increase the number of offspring. At the same time, kicking out those that don't...
That sounds simple enough, but it hides a lot of powerful things...
For instance, it took a long time for biologists to work out how selfless or "generous" behavours in animals could evolve (one reason is that helping your relatives can increase the number of copies of your own genes in future generations).
In terms of fishing it helps us to understand things like:
• Why would trout sometimes feed selectively?
• Why and when are fish sometimes impossibly spooky and sometimes reckless?
• What characteristics of a fly pattern can trigger a more committed attack from a trout?
Those things (and many more biology-based happenings) are really useful to know when deciding on your tactics, flies and tackle.

Why do Fish Take Artificial Flies?
Compare and Contrast
A very common tactic in biology is to compare what we know (or what we can find out) about one species with what might be going on in another.
So, it turns out that people know a LOT about how toads recognise prey (and predators) and how that creates particular behavioural responses.
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The physical structure of toads' eyes is very similar to fish and specific areas of their brains have been mapped in terms of the responses they control.
Toads eat worms and grubs - so researchers set out to discover the very simplest elements of any visual cues toads might use to recognise prey (and trigger a feeding response).
Long Story Short
A simplified summary of what they found was that any simple shape that was long and narrow (and which moved in the same direction as the long axis of that shape) would trigger the toads to track and then attack it.
They even linked the visual field of an image falling onto the retina of a toad's eye to the signals that were sent from the eye to particular parts of the toad's brain.
When moving in the same direction as the long axis, the signals sent from the retina down the optic nerve stimulated a particular bundle of brain cells (neurons). The ones that were stimilated are represented in red below in this diagram of a toad's eye watching the "prey-like" black line:
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A simple black "stick" shape moving in the same direction as its long axis is treated in the same way as a live worm crawling along (it is tracked and attacked by the toad)
With that particular bundle of neurons stimulated, the result was a fixed attack behaviour being triggered.
BUT, if the very same black line was moved at 90-degrees the long axis; something else happened.

The field of view of the retina was stimulated in a different way - which resulted in only a weak amount of signal being sent to the "attack prey" brain neurons... At the same time, stronger signals were sent to a different bundle of neurons.
The job of those brain cells was to "put the brakes on" the prey attack behaviour. So, if signals from those neurons are strong enough, they will block any signals telling the toad to attack. The picture below shows weak stimulation of the "attack prey" neurons (dull red) and stronger stimulation of the "block the attack" neurons (bright red) due to the image of the stick travelling across the retina in a vertical orientation

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The "block any prey attack" neurons are more strongly stimulated by a vertical stick travelling across the retina. Coupled with only weak stimulation of the "attack prey" neurons; the toad sits still and does not track or attack the fake prey.

Now, even though I'm skipping a lot of detail with this example, you can see how it's possible to trick a toad into treating a very simple shape in the same way it treats real, live prey.
It might not exactly be a talking trout - but it does teach us a lot about our job as fly anglers.
Homing in on the simplest set of cues (both in terms of shape AND movement) is an important part of understanding how to best design and present our flies.
The other - possibly even more important - lesson is to realise the cues used to detect potential threats can also be simplified. Understanding when and how those "predator threat" signals can be blocked (or turned down) is every bit as important to fly fishing success as fly design and presentation.
Most anglers pay far too much attention to flies and presentation tactics - and too little attention to how to avoid spooking fish.
Check out the next email coming soon to keep exploring these ideas and include them in your own fishing,

Paul
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I'm curious to know if the biologists in the PNWFF community believe this article is accurate, and if this type of knowledge can be helpful to freshwater anglers.

if anyone is interested I believe this is the website link to subscribe to their tutorials
 
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krusty

We're on the Road to Nowhere...
Forum Supporter
As a biologist and lifelong flyfisherman this sort of stuff is always fascinating. Often serves to illustrate that what we think we know about fish behavior may be far off the mark.

For example, while 'matching the hatch' is occasionally the ticket (and historically heavily emphasized) to an incredibly productive day, much of the time good flyfishing can often occur absent any observable hatch, with a small variety of fly patterns (and presentation techniques) that apparently trigger feeding behavior at a very fundamental level.
 

headduck

Steelhead
Hard to stay in business selling little black rods...or equivalent...

Sometimes I wonder if folks even want to know this stuff or just what fly/lure to buy.

Crazy to me.

Thanks for sharing.
 

Brian Miller

Be vewy vewy quiet, I'm hunting Cutthwoat Twout
Forum Supporter
Sometimes I wonder if folks even want to know this stuff or just what fly/lure to buy...
... and what rock to stand on.
Learning where fish lie, why a fish will either try to eat or ignore - avoid an object, practical techniques to trigger instinctive behavior of a fish to try to eat something, and how I will be able to bring it to the net in a given physical location is a puzzle (where - when - why - how) I enjoy solving.
 

headduck

Steelhead
... and what rock to stand on.
Learning where fish lie, why a fish will either try to eat or ignore - avoid an object, practical techniques to trigger instinctive behavior of a fish to try to eat something, and how I will be able to bring it to the net in a given physical location is a puzzle (where - when - why - how) I enjoy solving.
...and although the image is similar... it's a different puzzle every time.
 
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