"Bob Weinberger" wrote in message
news:6bIii.4313$za5.1414@trndny09...

"Wolfgang" wrote in message
...

"Bob Weinberger" wrote in message
news:MYBii.8255$DM4.5582@trndny06...
snip
Meanwhile, and not so incidentally, I've seen indications in recent years
that the salmons' famed fidelity to their natal streams is not so
hard-wired and infallible as was once supposed. I believe the issue,
like so many others (lifelong monogamy in various species comes quickly
to mind) is still pretty controversial, but even the staunchest advocates
(well, at least among those who take their heads out of their asses long
enough to enjoy the novelty of free oxygen) have had to admit at least
that there are occasional and incontrovertible exceptions.
snip
Wolfgang
The tendency for a relatively small % of salmon to stray from returning to
their natal streams to spawn has been known for at least 30 years, maybe
longer. However, of all the studies that I have seen, none ever documented
straying of more than one or two drainages past their natal stream,
though I seem to recall several reports of fish straying into and spawning
in streams that were significantly short of reaching their natal streams.
Fishery Bio's theorize that this, along with the tendency for some salmon
to stay in the ocean for lesser or longer than "normal" periods (e.g.
Chinook may stay anywhere from 1- 5years in the salt), is an adaptation
for repopulating streams that suffer a temporary catastrophe. That's why
the Coho Salmon run on the North Fork of the Toutle river, which was
devastated by the eruption of Mt. St Helens was back to pre-eruption
levels within about 5 years.

All of which, characteristically for this place, leads us further astray
from the original question concerning how much was known how early about
salmonid homing tendencies, and how this might bear on Jordan's error.


But, all interesting (and central to a reading of Jordan's "How the Trout
Came to California") in its own right. A quick return to pre-eruption
population levels in streams devastated by Mt. St. Helens illustrates nicely
that the importance of strays is grossly disproportionate to their small
numbers. Somewhat ironically, it makes clear to the modern reader (or CAN
do so, anyway) what would otherwise be inexplicable given the universally
promulgated grade-school model of absolute fidelity that many people carry
through life, and that would never have been a problem before an increase in
scientific knowledge taught us that they always return home to spawn.

Wolfgang