Re: RE: NANFA-L-- chemical defenses -- madtoms and others

Wallace Bilingham (wally_pike-in-hotmail.com)
Wed, 16 Feb 2005 01:02:02 +0000

Birds are not in the least bit effected by capsaicin, neither are iguanas
they eat lots and lots of peppers in South America and spread the seeds. I
used to feed my iguana habenero peppers from my garden and he LOVED them.

Wally

>From: dlmcneely-in-lunet.edu
>Reply-To: nanfa-l-in-nanfa.org
>To: nanfa-l-in-nanfa.org
>Subject: Re: RE: NANFA-L-- chemical defenses -- madtoms and others
>Date: Tue, 15 Feb 2005 14:34:10 -0600
>
>Bruce, seems like I read that the birds swallow the peppers whole, and so
>do not release the capsaicin from the peppers until digestion is initiated
>in the gizzard. Then the capsaicin has the same cathartic effect that it
>has in people -- that is, the undigested seeds are passed more quickly than
>they would be if there were no capsaicin involved. The capsaicin
>stimulates pain receptors in mammals, which masticate the chili berries,
>but not in birds, which have no teeth. Seems like Jantzen, of University
>of Pennsylvania (or one of his students) did some work on this with
>long-billed thrashers in S. Texas and in Arizona, and found that indeed,
>capsaicin is cathartic in them. These birds eat a lot of peppers where
>they grow wild as part of the shrub stands in S. Texas. I think that there
>was even speculation that the chili advertises itself to the birds by its
>bright colors.
>
>Could pain on attempted predation have the same benefit for madtoms that
>nausea on ingestion of monarch butterflies has in their bird predators? In
>that case, after a bluejay eats a monarch, the butterfy's chemical defenses
>(cardiac glycosydes present in the milkweed foliage eaten by the
>caterpillar and sequestered in the internal organs of the butterfly) sicken
>the bird, and it vomits. A person would find this experience unpleasant.
>Bluejays that have had this experience then avoid monarchs in the future.
>Since monarchs in the same vicinity are likely to be genetically related,
>the prey is protecting its kin, and the trait of sequestering these poisons
>is naturally selected. Orioles that prey on monarchs with impunity,
>however, dissect the butterflies and strip out the offending organs, which
>they drop on the ground, eating the non-toxic parts!
>
>Maybe a bass that eats a madtom has an unpleasant experience, (a sting in
>the gullet or stomach. The feeding method of a bass is unlikely to result
>in a sting in the mouth), and so avoids madtoms in the future. That would
>protect the madtoms kin, thought not the one eaten. Or, like you said,
>maybe the protection evolved historically for predators that no longer
>exist. Or maybe it works very well for predators that require more
>handling of the madtom than does a bass -- say a heron, which has to
>manipulate its prey, or a racooon, which has to handle the fish with its
>paws, then its mouth. More chances to be stung. One thing wrong with this
>scenario is that madtoms tend to be cryptically colored, and to seek
>protective shelters. In other animals, where a prey is protected in the
>way I've speculated for madtoms, the protected animal exhibits warning
>coloration -- the bright colors of a monarch, or a wasp, for example.
>
>Interesting to consider, anyway.
>
>Dave
>
>David L. McNeely, Ph.D., Professor of Biology
>Langston University; P.O. Box 1500
>Langston, OK 73050; email: dlmcneely-in-lunet.edu
>telephone: (405) 466-6025; fax: 405) 466-3307
>home page http://www.lunet.edu/mcneely/index.htm
>
>"Where are we going?" "I don't know, are we there yet?"
>
>----- Original Message -----
>From: Bruce Stallsmith <fundulus-in-hotmail.com>
>Date: Tuesday, February 15, 2005 1:40 pm
>Subject: RE: NANFA-L-- Michigan Chapter
>
> > Plants are necessarily the best comparison. Birds have little or
> > no sense of
> > taste, for instance, so the various peppers are hot to deter other
> > herbivores, while birds eating the fruits benefits the pepper
> > because birds
> > can spread the seeds by pooping. Madtoms may benefit even a little
> > from
> > being able to inject a noxious substance into a predator, which
> > could work
> > for a positive selection force on the venom. Or was the venom more
> > effective
> > against a predator in earlier times who no longer exists, and the
> > venom is
> > now vestigial? Just a thought, you never know.
> >
> > --Bruce Stallsmith
> > the springlike Tennessee Valley
> > Huntsville, AL, US of A
> >
> > >From: jlw-in-dune.net
> > >Reply-To: nanfa-l-in-nanfa.org
> > >To: nanfa-l-in-nanfa.org
> > >Subject: RE: NANFA-L-- Michigan Chapter
> > >Date: Tue, 15 Feb 2005 12:30:59 -0700
> > >
> > >Don't forget also, that predators develop defenses against their
> > prey's>defenses. In other words, they can evolve to be list
> > effected by venom, or
> > >its
> > >method of injection. Certainly individuals-in-any given time are
> > going to
> > >be
> > >more effected than others -- we can see this even in human
> > beings. I love
> > >hot
> > >peppers, and make a plate of chili that makes my S. O. want to
> > leave the
> > >house
> > >(we'll pretend it's the CHILI that does that). Yet, I have a
> > friend who
> > >thinks
> > >its "Not bad, a little weak."
> > >
> > >Fish are the same way -- one bass grabs a madtom and it's like a
> > platefull
> > >of
> > >hot peppers. Another grabs one, thinks, "SPICY!" and heads off
> > in search
> > >of
> > >another. :)
> > >
> > >JW.
> >
> >
> > /------------------------------------------------------------------
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>
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