I suppose they only take debris that moves in a natural - non-alarming - manner. If a fly is dressed in a way that allows it to behave naturally within the moving water the fish is less likely to be "put off". A fly can look natural to us, in the vise or in a glass of water, but have negative triggers when in action. Could this be included in a hypothesis trying to explain differences if they exist?tie2fish wrote:I'm no expert on what causes trout to eat or reject different fly designs, but I have seen a couple of underwater videos that suggest that they (trout) take a significant number of debris bits into their mouths and then reject them in the course of a day. The frequency with which this happens appears to be related to the velocity and clarity of the water in which they are holding. If a trout cannot, for any reason, distinguish between debris and real food without mouthing it, is it realistic for us to speculate about whether their decision to eat a fly or not is based on the size ratio between a hook and the materials that are fastened to it? Just sayin ...
dd