There are several reasons why fish can be selective in what they take in their mouth or not. In my experience the two most common reasons we fly fishermen will be facing often are:
1. The fish has learnt to identify typical fishing strategies as being dangerous for him.
This can be the size and/or movement of the fly. Sometimes even the color may be it. Or it can be the size (visibilty) of the leader. Also the shadow of the fly line often may support the fish to refuse. The pure sound/noise of the fly, the fly line and/or leader may force the fish to run off or to just refuse. The depth in which we offer our fly easily can be the bottleneck. If everyone fishes the surface make sure to fish deep (or at least below the surface) for the big (smart) ones.
Fair to summarize - the more fishing pressure there is, the harder it gets to have a perfect strategy to fool the fish ready (while others are already stopped working at all). Most fish learn fast!
2. The fish has one (and one only) strategy to effectively hunt down one sort of bait - while ignoring all other bait.
When we aim to catch pike we wouldn't fish for pike, perch and zander at the same time. All of these predatory fish behave different and thus we need different strategies to be successfull on each of them. This is the same for the fish. Let's have a look at coastal Sea trout. When they hunt sandeal/tobis they are looking for baitballs and not single ones. The single ones are way too fast running off as soon as the Sea trout gets in a distance of less than 6 to 8 meters! Too much energy would be wasted in chasing just one sandeal. So the Sea trout are running into the baitball instead and then take several of them. Instead when eating on marine Gammarus the Sea trout will slowly take one after another one. Gammarus don't run off. Two different sorts of bait and two very different feeding strategies. In 95% of the situations Sea trout will not shift back and forth between these two strategies but ignore one or the other one!
In order to be successful in hooking up the fish in front of us we need to work out the best strategy and then make it work on the first cast!
To find the best strategy we need to understand fishing pressure and it's consequences to fish behaviour as well as how the bait acts when the fish comes in close to them.
The bigger the fish are, the better they know how exactly their natural bait behaves. Everything behaving different easily can warn the fish or just make it ignoring our fly.
There are a lot of other key factors that we can take into account. But the truth is, that matching these 2 helped me to significantly increase my success in catching on most (if not all) species of fish.
Hopefully I could help you to crack the code on your favorite species of fish!?
Great week to all of you!
All my best
Our week in pictures...