Catching The Dumb One
Selectivity in fish, especially trout, has always been
heralded as a mark of intelligence particularly among
dry fly anglers. Each time a trout spurns our offering
and compels us to change flies we consider that rejection
as a mark of superior intelligence or at least very great
discernment. This allows us big-brained humans [?] to feel
less humiliated by a cold-blooded creature with a brain
that's smaller than a pea! While I enjoy fishing for trout
that are feeding on a specific insect I believe that they
are not the smart ones but the dumb ones.
By Neil M. Travis, Montana
Several years ago I spent a considerable amount of time
investigating the subject of selectivity in trout. I read
most of the available literature on the subject, and
carefully considered all of the popular theories. Since
we have yet to find a talking trout all our carefully
and logically derived conclusions are really just smoke
and mirrors. Quite frankly we don't know why trout feed
selectively, but we have made many educated guesses.
Fisheries biologists will tell you that selectively is
not a mark of intelligence since given the size of the
trout's brain it is very unlikely that a trout ever
processes any information in a logical manner. The parts
of the trout's brain that are most highly developed are
those related to non-cognitive functions like breathing,
swimming and fleeing. They are not Einstein or even
Frankenstein. It is safe to say that the trout that
turned up its nose at your carefully tied mayfly
pattern only to eat some miniscule bit of flotsam too
small for you to see was not rejecting you due to
intelligence but something far more primal.
A trout that is feeding selectively is like a person
that only eats tofu. It's not great, but it's filling,
so every meal is only tofu. When a big juicy steak is
offered to them they refuse it and just continue to eat
tofu. Intelligence choice? If you think so your
intelligence level is very close to that of a trout.
In a nutshell that is how selectivity works. Trout start
feeding on a specific form of food but when presented
with an equally edible and nutritious food form they
continue to feed 'selectively' on whatever they have
previously been consuming. They chose tofu over a steak.
Trout that are feeding randomly are actually far more
difficult to catch than trout that are feeding selectively.
Once you have figured out what selective trout are feeding
on the rest is, as Sherlock Holmes would say, 'elementary
my dear Watson.' Random feeders are the truly difficult
ones, the salad bar trout that are sampling a little of
this and a little of that, but seldom the same thing twice.
Several years ago I chanced upon a situation on a well-known
trout stream that illustrates my point. During the day a
steady hatch of small olive mayflies produced a nearly
continual rise, and having 'gotten their number' I had
been consistently catching trout. As the sun began to
set I chanced upon a dozen or so real good fish feeding
along a grassy bank. Suddenly the game changed. They were
not interested in any form of the small olive mayfly that
had been so productive during the day, and after changing
flies several times I waded below the steadily rising fish
and sampled the surface of the water with my aquarium net.
In the drift line along the bank was a steady stream of
small ants, beetles, aphids, leafhoppers, and similar
terrestrial insects, a potpourri of tiny delectable
morsels that were being served up to the waiting trout
lined up along the bank.
Wading back into casting position I present the last
trout in the lineup with a small jassid. Bingo, fish
on. Moving up to the next fish I tried several different
patterns before I got a take, and the same with all the
other trout in the lineup. Each fish wanted a different
fly, although stomach samples taken from several of
these fish [using a stomach pump not a knife] demonstrated
that they all were eating some of everything that was
coming down the drift line. If they had been feeding
selectively on one type of insect I would not have had
to change flies for every fish I caught, but since they
were feeding randomly they were rarely feeding consecutively
on the same type of insect.
I love a challenge, but give me the dumb ones, those
selectively feeding trout that consistently are eating
tofu, and then I can truly look like an expert. ~ Neil M. Travis, Montana
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