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Date: | Wed, 25 Apr 2012 16:35:57 -0400 |
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Hi,
I think it may be useful to define adaptation and habituation as it relates
to birds and bird behavior.
Adaptation is generally considered to be an alteration in the genome
resulting in change in morphology or physiology which enables a species to
exploit some aspect of the ecology, resulting in higher reproductive
success. Darwin's finch beaks being the cardinal example
Habituation is a change in behavior but not morphology or physiology. Is
considered to be learned, eg British Great Tits learning to remove the caps
from milk jugs. It may take multiple generations for this behavior to be
spread widely in a population or it can happen very quickly as with the
British Great Tits.
There is most certainly a genetic element to behavior and it can be
selected. Like the tame Russian foxes who were selected and breed based
upon response to a hand being brought quickly to the cage near the foxes
face. Why are Wood Duck's so skittish? Most likely because only
the skittish survived when they were hunted to near extinction, so has this
behavior has become encoded in their DNA? Why are Ivory-billed Woodpeckers
so good at hiding from people? Most likely a similar reason. I think one
of the reason's Williams found Piliateds to be rare was because they were
also very good at avoiding people. When I was a boy I remember the old
hands at birding, saying that seeing anything other then the distant white
flashes of a Piliated flying away was a rare treat. However during my
lifetime I have seen this species become habituated to human presence.
When a diverse and intelligent species are confronted with a problem there
may not be any genetic component. Crows nesting in sub urban settings may
be cultural. I am currently doing some work with Canada Geese and have
learned how quickly they change their behavior and responses in reaction to
certain conditions. It is actually quite astonishing. Eastern Bluebirds
come to feeders offering hulled sunflower. This is something that just
began in the last decade and is most certainly learned and cultural.
Overall this is a fascinating subject and requires abandoning the
creationist notion that intelligence suddenly sprang into existence when
our species showed up on the planet. When it comes to Ohio's avafauna
behavioral changes may be rapid, like our bluebirds, or may take
generations. It is always interesting to observe these changes over time
and make note of them. When it comes to the range of bird species, such as
our Fish Crows, this will not be the first time in my lifetime such a
rapid expansion has occurred. It is impossible to assign causality to
these changes and these may be part of a normal range of variation which is
spread over centuries.
Haans Petruschke
Kirtland
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