Fish behaviour
Posted: Sun Oct 09, 2011 9:34 pm
Just some observations and considerations which may be of interest.
Spooked wild fish can disappear for a very long time. I have never actually waited days, but have often waited hours, without a sign of a fish returning. On the other hand, I have seen fish come back on the feed fairly quickly after a canoe, ( or even a whole fleet!), has passed, especially on the stretches where there are a lot of canoes, and also near paths frequented by walkers, some fish will continue to feed. I assume that the fish which are "accustomed" to this disturbance are simply conditioned over time not to react to it as a "danger". There must be mechanisms which eventually allow fish to ignore certain things, as they would otherwise flee from everything all the time. I assume that exposure conditioning is one such mechanism. Another example is fish feeding where cows mill around in the water. They must have become accustomed to this, as otherwise they would flee.
Although it is possible, even likely, that a better sensory ability plays a part in extended survival, there are a lot of factors arrayed against a fish. Fish survive because they survive. A mature fish has already beaten huge odds to become mature. Blind chance plays a part as does genetic preconditioning, and fitness. All the large browns ( > 3 lbs), I have caught more or less "locally" have been extremely specialised, only feeding at night, and only taking a couple of fish before retiring to their boltholes, where they don't take anything at all, even if the bolthole is known and accessible to the angler. This means the fish manages to get enough large amounts of protein in a short time, which allow it to grow faster, and also reduces its exposure to predators to a very high degree. Perhaps only an hour or so at night when it is actively feeding. Perhaps such fish are genetically programmed to turn cannibal fairly early, and to feed at night, or only the fish which turned cannibal early and fed at night survive to this size, however this may be, this aids their survival very greatly.
There are always problems when looking for cause and effect in various fish behaviour. Humans tend to anthropomorphise these things, but in the vast majority of cases there is no single specific reason for various things, large, ( and mature), fish are the culmination of many factors and there is no way to even know them all, most especially not in specific cases. As a rule the fish with the best genes will survive to breed, so passing on that genetic programming. Those that don't survive don't breed and so don't pass on their genes. This constantly hones the survival ability of the fish.
I am not at all happy with some statements in regard to fish memory. If fish can be conditioned to behave in certain ways, and they obviously can, then they must have something which allows them to be conditioned. Remember that what we are talking about here is the "re-programming" of instinctual behaviour. This alters the "normal" instinctual and involuntary responses! This is a major adjustment. It is not clear at all how this functions. There is no way for a fish to learn in the sense of stored memories as a higher brain function, ( which according to various authorities it does not have), and even if it could, that would not affect the instinctual and involuntary responses to various things.
As an example, humans can control a lot of things, but they can not re-program instinctual reflexes as a matter of will. You are unable to stop yourself blinking under certain conditions, although you can blink at will if you wish, there are plenty of other examples. A fish can not decide not to do something, as it lacks the capacity to make decisions, also such a function would take far too long in the environment in which a fish lives, it must react immediately, instinctively and CORRECTLY to various stimuli, or it dies. In many cases it will die anyway, because the response was not "optimal", or was useless in that situation, but the general trend will then be that fish which make the "right" instinctual response survive and the others don't. The large fish have not "learned" anything, they were just the only ones who responded "correctly" to the various stimuli.
There are a lot of very complex factors and inter-dependencies involved here and I don't think there is any way to unravel them to the extent that they might be useful to an angler seeking to catch a certain fish, except in the case of observed behaviour, as opposed to knowing the reasons(s) for that behaviour, or being able to extrapolate or predict it.
Panicked flight is more or less the "final" instinctual survival response, ( in humans as well), but people have different panic threshholds, even in more or less identical situations, and it is reasonable to assume that all other animals do as well. Panic can be "contagious" as well to a degree, with one animal panicking a whole herd. Extrapolating this to fish, it is reasonable to assume that a single fish can panic a whole shoal, simply by being the first to panic, even in cases where there is no apparent cause for panic. Instinctual reactions also depend on the degree of awareness.
As far as angling goes, I generally assume that anything I do which the fish can perceive is likely to result in my not catching that fish. This works pretty well when I actually succeed in doing it. In cases where the fish are aware of "something", it may still be possible to catch some, where in other cases it wont, or the fish will simply flee.
This is also why I concentrate mainly on stealth, and on prey behaviour, rather than on trout behavior as such. There is no way to accurately predict what various fish will do, or to know exactly "why" they do it, but observing how they react to various prey reveals patterns of behaviour which are quite likely to occur under certain circumstances. The only real difficulty there is ensuring accurate observation.
TL
MC
Spooked wild fish can disappear for a very long time. I have never actually waited days, but have often waited hours, without a sign of a fish returning. On the other hand, I have seen fish come back on the feed fairly quickly after a canoe, ( or even a whole fleet!), has passed, especially on the stretches where there are a lot of canoes, and also near paths frequented by walkers, some fish will continue to feed. I assume that the fish which are "accustomed" to this disturbance are simply conditioned over time not to react to it as a "danger". There must be mechanisms which eventually allow fish to ignore certain things, as they would otherwise flee from everything all the time. I assume that exposure conditioning is one such mechanism. Another example is fish feeding where cows mill around in the water. They must have become accustomed to this, as otherwise they would flee.
Although it is possible, even likely, that a better sensory ability plays a part in extended survival, there are a lot of factors arrayed against a fish. Fish survive because they survive. A mature fish has already beaten huge odds to become mature. Blind chance plays a part as does genetic preconditioning, and fitness. All the large browns ( > 3 lbs), I have caught more or less "locally" have been extremely specialised, only feeding at night, and only taking a couple of fish before retiring to their boltholes, where they don't take anything at all, even if the bolthole is known and accessible to the angler. This means the fish manages to get enough large amounts of protein in a short time, which allow it to grow faster, and also reduces its exposure to predators to a very high degree. Perhaps only an hour or so at night when it is actively feeding. Perhaps such fish are genetically programmed to turn cannibal fairly early, and to feed at night, or only the fish which turned cannibal early and fed at night survive to this size, however this may be, this aids their survival very greatly.
There are always problems when looking for cause and effect in various fish behaviour. Humans tend to anthropomorphise these things, but in the vast majority of cases there is no single specific reason for various things, large, ( and mature), fish are the culmination of many factors and there is no way to even know them all, most especially not in specific cases. As a rule the fish with the best genes will survive to breed, so passing on that genetic programming. Those that don't survive don't breed and so don't pass on their genes. This constantly hones the survival ability of the fish.
I am not at all happy with some statements in regard to fish memory. If fish can be conditioned to behave in certain ways, and they obviously can, then they must have something which allows them to be conditioned. Remember that what we are talking about here is the "re-programming" of instinctual behaviour. This alters the "normal" instinctual and involuntary responses! This is a major adjustment. It is not clear at all how this functions. There is no way for a fish to learn in the sense of stored memories as a higher brain function, ( which according to various authorities it does not have), and even if it could, that would not affect the instinctual and involuntary responses to various things.
As an example, humans can control a lot of things, but they can not re-program instinctual reflexes as a matter of will. You are unable to stop yourself blinking under certain conditions, although you can blink at will if you wish, there are plenty of other examples. A fish can not decide not to do something, as it lacks the capacity to make decisions, also such a function would take far too long in the environment in which a fish lives, it must react immediately, instinctively and CORRECTLY to various stimuli, or it dies. In many cases it will die anyway, because the response was not "optimal", or was useless in that situation, but the general trend will then be that fish which make the "right" instinctual response survive and the others don't. The large fish have not "learned" anything, they were just the only ones who responded "correctly" to the various stimuli.
There are a lot of very complex factors and inter-dependencies involved here and I don't think there is any way to unravel them to the extent that they might be useful to an angler seeking to catch a certain fish, except in the case of observed behaviour, as opposed to knowing the reasons(s) for that behaviour, or being able to extrapolate or predict it.
Panicked flight is more or less the "final" instinctual survival response, ( in humans as well), but people have different panic threshholds, even in more or less identical situations, and it is reasonable to assume that all other animals do as well. Panic can be "contagious" as well to a degree, with one animal panicking a whole herd. Extrapolating this to fish, it is reasonable to assume that a single fish can panic a whole shoal, simply by being the first to panic, even in cases where there is no apparent cause for panic. Instinctual reactions also depend on the degree of awareness.
As far as angling goes, I generally assume that anything I do which the fish can perceive is likely to result in my not catching that fish. This works pretty well when I actually succeed in doing it. In cases where the fish are aware of "something", it may still be possible to catch some, where in other cases it wont, or the fish will simply flee.
This is also why I concentrate mainly on stealth, and on prey behaviour, rather than on trout behavior as such. There is no way to accurately predict what various fish will do, or to know exactly "why" they do it, but observing how they react to various prey reveals patterns of behaviour which are quite likely to occur under certain circumstances. The only real difficulty there is ensuring accurate observation.
TL
MC