DO FISH HAVE PHD'S?
We have all heard about that 'wily' brown trout or that 'cagey' old bass, but what do we mean when we use such terms? Too often I think that when we use these terms we infer that these individuals have a degree of intelligence that is superior to other members of their species. It is fortunate for us that fish are not high on the intelligence scale or catching them would be much more difficult. If they were able to learn soon we would not catch any fish. Fish react to their environment and those that are most successful at that live to swim another day. Since fish are not high on the intelligence scale why are they sometimes so hard to catch?
In our modern times most of us are far removed from the world of nature. Our ancestors understood that the any creature, including man, which honed their survival skills, had a better chance to live a longer life. The natural world is a heartless place and the creature that comes to terms with that reality is the one that survives. The 'wily' brown trout and the 'cagey' old bass are not smart or intelligent, as we measure those qualities, but they are wise in the ways of survival.
The survival story begins at the moment a fish hatches from the egg. The survival rate for many newly born creatures in the wild is very low, often less than ten percent. This rate increases for animals that have protective parents but since most fish only provide minimal protection, if any for their young, the survival rate for fry in the first few months of life is comparatively low. Fry are at the very bottom of the food chain being prey for everything from insects, birds, mammals and even their own parents. Fry tend to congregate together to increase the odds since numbers tend to confuse predators and they prefer to stalk the lone prey species. For many prey species, especially when they are young, there is safety in numbers.
Under natural conditions the first year of any animal's life is the most dangerous. It is during this time that many of the youngsters are culled out by predators and disease. Those that survive through the first year have an increased chance of reaching maturity. In fish species the fry that learn to flee at the first hint of danger, real or perceived, are the ones that have the greatest chance of survival. It is this characteristic that gives the impression that fish are intelligent.
If you have ever observed fry you can demonstrate exactly what I am talking about with a very simple experiment. Wave your hand over a school of fry and watch the reaction. Your hand does not represent a real threat to those small fish but their reaction will be instantaneous; they will all promptly scatter and try to hide. Those fry that do not flee immediately, even to this harmless motion, are the ones that will not survive. Later in life the shadow of a non-fish eating bird or your fly line may elicit the same reaction.
Fish that survive the first year of life soon move into areas that provide maximum protection from predators. Structure, like weed beds, logs, brush piles and similar objects are places that provide this type of protection. These areas also are attractive to various types of food that the fish can eat but they provide places to hide from predators. An area that has shallow water that borders deeper water, especially if the deeper water has weeds or submerged logs or brush, is a great place to find many fish species. A fish can move into the shallow water to feed and quickly slip back into the deeper water if they perceive danger. When an angler hooks a fish in that area and it quickly shoots back into the deeper water and buries itself in the weeds or wraps the angler's line around a submerged log that fish is deemed to be smart. However, in reality, the fish is only reacting to stimuli that have proven effective in avoiding danger.
Many anglers believe that fish can see the leader and when they see it they shy away. Yes, the fish can see the leader but unless the fish is capable of deductive reasoning the leader means nothing. If the leader is a giveaway what about the hook? They can see the leader, they can see the hook but all that means nothing. If it did we would never catch any fish. The leader only matters if it affects the way the bait; fly, plug, worm etc., acts when it's in the fishes view. If the leader makes bait act unnaturally then the fish will avoid it and continues eating those things that act normally. If something does not act natural the fish that lives to see another sunrise is the fish that avoids that thing. Anglers call it drag but no matter what name you give it, if it makes your offering act different than the natural's fish will generally ignore it. It's a matter of survival not intelligence.
To the fish we are a predator and if we are going to succeed in hooking the older and larger fish we have to be a better predator. Those bigger fish are not smarter, wiser or wilier they are simply more adept at survival. Unlike their smaller brethren they have survived more close calls with predators, even anglers, and they have honed their survival skills. They did not get to be older and larger by being careless when it comes to survival.
Burned in my memory is a large trout that I encountered many years ago. This fish was living in a stream that is open to the public and gets lots of angling pressure. I hooked and landed the fish and released it without even removing it from the water. It was a handsome fish 18+ inches in length. After I released the fish it swam a short distance away into a slot of deeper water and when my fly floated over his position it rose and took the same fly that I had caught him on just a few minutes before. So much for intelligent fish!