Why do fish eat our fly imitations? I have a few observations I’d like to share today.

I marvel when a trout rises to my fly. Sometimes you barely see a ring when the fish breaks the surface and slurps the fly underwater, like using a straw. Or all of a sudden, a fish head slowly comes out of the water and eats your fly. Lastly, the explosion take when a fish quickly pounces on a Salmonfly.

Cutthroat Rising to Eat - 4 | www.johnkreft.com

You’ve seen all of those different takes, haven’t you? It’s why I enjoy dry fly fishing so much. But why do they rise to an imitation when there can be so many naturals floating on the water?

Blanket Hatch | www.johnkreft.com

The image above is a blanket hatch of PMDs or PMD look-alike mayflies from a few years ago. If you cast your imitation in the middle of them, why would a fish eat it and not a natural?

Here’s another example of lots of bugs. These were scooped up in an eddy where they collected using a paint strainer over a net.

Epic Mayfly Hatch | www.johnkreft.com

I’ve talked about slipping a mesh paint strainer bag (Amazon affiliate link) over your net to capture insects.

We’ve been seeing a lot of Pale Morning Duns (PMD) and Baetis / Blue Wing Olives (BWO) flies on the water recently and fish rising to them.

Here is an example of a PMD floating on the water.

PMD on Water | www.johnkreft.com

And an Improved Sparkle Dun imitating a PMD that I tie and fish.

Improved Sparkle Dun - PMD | www.johnkreft.com

Why would a fish eat this fly? Besides the wing silhouette, I think the tail or shuck is the key. Perhaps the fish sees the fly and realizes it is stuck in its nymphal shuck and can’t quickly fly away.

If you are a regular here at RiverKeeper Flies, you recall I fish a Sparkle Dun fly pattern quite a bit. It’s my favorite fly pattern for a reason, it works!

Rainbow with Fly | www.johnkreft.com

Here’s another example of an effective fly, my RiverKeeper Soft Hackle Cripple. I believe the hackle imitates the natural’s wing stuck on the surface of the water.

PMD with RK Soft Hackle Cripple | www.johnkreft.com

Here is a Rainbow Trout I landed from the Owyhee River a week and a half ago.

Owyhee River Rainbow | www.johnkreft.com

It ate the remains of a Compara Spinner – Biot Body fly.

Demolished Compara Spinner - Biot Body | www.johnkreft.com

Let me say that again, it ate this fly, It’s not a picture of the fly AFTER the fish took the fly. Why would it do that? Here is the “before” picture.

Galloup's Compara Spinner - Biot Body Bottom View | www.johnkreft.com

Lastly, here is another fly we’ve seen trout move to with intent. It’s the Almost There Baetis. I haven’t figured out why it’s effective. All I know is it works!

Almost There Baetis - Olive | www.johnkreft.com

It’s tied on a Daiichi size 18 hook, but the fly is more like a size 20 or 22. In other words, it’s a speck on the water. Why would a fish move two or three feet to eat the fly? We’ve seen fish do exactly that and eat this fly. I have trouble locating it on the surface!

I was lucky enough to catch this beautiful Rainbow Trout yesterday on the Metolius. I cast my size 18 Improved Sparkle Dun close to shore and he came out and ate my fly. Why? I don’t know, but I’m grateful!

Metolius October Rainbow | www.johnkreft.com

I’m headed to the river again today hoping to see a few more heads.

Rising Fish | www.johnkreft.com

It’s good to be home.

Enjoy…go fish, stay safe!

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  1. Haven’t we all pondered this question. a metal hook covered with feathers and thread, and attached to a plastic string… what are those fish thinking.
    Some days we know the fish are smarter than we are, other days, we win. Just glad that every now and then, the bigger brain wins out.

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