Why do Perdigons Work?
Perdigons consist of a tungsten bead, coq de leon, thread, maybe quill, maybe something flashy, and UV Resin. They are easy to tie and don't consist of much but damn are they effective. So why exactly do perdigons work??
Let's start by defining a Perdigon or Euro style nymph.
What is a Perdigon
Tungsten bead, UV coated or slim bodied, jigged hook, 4-15 fibers of coq de leon. There is some variation to this, but these flies are intended to get down with next to know resistance and bounce along the bottom without hanging up.
Why do Perdigons Work?
The answer to this question is incredibly simple when it is broken down. Perdigons work because they get to where the fish are, they do it efficiently, and they stay there. Fish feeding subsurface, on the nymph stage of aquatic insects, feel very safe sitting at the bottom of a deep hole and crushing anything and everything that looks like a bug with little reservation. Where can MEGA critters be found? Exerting as little energy as possible belly bumping the river bed, crushing snacks.
Here is an example.
You cast a hopper with a rubberleg dropper, fishing the Gallatin of course, above a rapid drop off in hopes of sticking a huge brown on the Pat's Rubberleg. Your flies hit the water about 2 feet above the drop. Your dropper begins its descent. Legs and chenille catch the water and slow the drop. By the time the your rubberleg drops over the ledge it has only made it to about 18 inches below the surface. This would be great other than the fact that Walter Brown is sitting at 36 inches deep at the very top portion of this hole. Thats right, your second fly just passed well over a fish that is unwilling to move at all to eat a fly. No bueno.
So now you cast 4 feet above the drop right? Great. Except, the edge of the ledge is only 18 inches deep. Your fly just got caught the rocks above the ledge. Okay just mend. You mend, your fly continues it's decent and still passes 12 inches over the MEGA browns head. Again, no bueno. Let's try again with a Perdigon.
The Perdigon is smooth, hydrodynamic, and heavy. Now you cast 1 foot above the drop. Umpqua's Lite Brite Butano Perdigon starts bombing toward the bottom of the river. It barely clears the edge of the drop and is still plummeting. Nearly immediately it hits the bottom of the river. No snag due to how the perdigon rides under the water, bead down, coq de leon and hook point up. What do you know, that fly is right in front of the MEGA brown. BINGO! Fish on.