[Ecoed] Re: indirect competition

Thu May 3 00:21:48 GMT 2007

Hi Kristen:

To illustrate interference aka direct competition I like to use two bits
from the popular "literature".  One is the pages on bird song in Gary
Larsen's There's a hair in my dirt".  This has a forward by E.O. Wilson and
shows that nature is not all sweetness and light.  It is suitable for high
schoolers and maybe middle schoolers.  The other is by Dr. Seuss in his "On
beyond zebra".

And NUH is the letter I use to spell Nutches
who live in small caves, known as Nitches, for hutches.
These Nutches have troubles, the biggest of which is
the fact there are many more Nutches than Nitches.
Each Nutch in a Nitch knows that some other Nutch
would like to move into his Nitch very much.
So each Nutch in a Nitch has to watch that small Nitch
Or Nutches who haven't got Nitches will snitch.

Note that this fits the criteria of limited and defendable resources.

RE the suggestions sent by others in answer to your query the trick or treat
example is OK but the bee vs butterfly example is flawed because a longer
proboscis can get into deep narrow flowers that bees cannot get into (it is
an example of coevolved flower - pollinator or generalist vs. specialist).
The change in growth form in response to crowding is a bit slippery because
light cannot be used up but it can be denied in part by shading (is this
interference or exploitation?).

I have just reviewed the AAAS Kinetic City and wonder how your project is
related to it if at all.  It has only one exercise sort of related to
competition with bill shapes and food types but it is more about adaptation.
Many of the exercises are cute and one (nowhere to hide) is excellent on the
concept of natural selection.  But in general the illustration of concepts
is weak and there is nothing on the process of science.  I find this a
disturbing lack in science museums, nature centers, TV series like animal
planet, and in the recent Planet Earth.  Many of these are good on
conservation and stewardship but they could do more.  A penny for your
thoughts.

Cheers, Tom

On 5/2/07 11:33 AM, "Kristen Lennon" <klennon at aaas.org> wrote:

> Dear Tom,
> 
> Those are fantastic examples. Thank you so much for sharing them. It's
> too bad that they weren't allowed to be posted (I don't understand why)
> to the list server because they would be an asset to anyone working in
> this area. I would love to see your examples of direct competition if
> you wouldn't mind sharing.
> 
> Best,
> Kristen
> 
> Kristen A. Lennon, Ph.D.
> Research Associate
> Project 2061
> American Association for the Advancement of Science
> 1200 New York Ave., NW
> Washington, DC 20005 USA
> 
> 
> Tel:202-326-7032
> E-mail: klennon at aaas.org
> http://project2061.aaas.org
> 
>>>> Thomas Poulson <tomandliz at bellsouth.net> 5/1/2007 3:29:10 PM >>>
> Kristen: 
> 
>  Eco Ed replied that I am not allowed to post to their web site so I
> am
> forwarding it to you directly.
> 
> Cheers, Tom
> 
> ------ Forwarded Message
> From: Thomas Poulson <tomandliz at bellsouth.net>
> Date: Tue, 01 May 2007 10:53:52 -0400
> To: <ecoed at ecoed.net>
> Conversation: Ecoed Digest, Vol 37, Issue 1
> Subject: Re: Ecoed Digest, Vol 37, Issue 1
> 
> Kristen et al:
> 
> Here are some examples of resource aka exploitation competition that
> work
> even for primary school kids.  For middle school kids I would add the
> idea
> that, in contrast to territoriality resource competition is indirect,
> does
> not require contact between individuals, the resource cannot be
> defended or
> pre-empted, competition never results in direct harm, and is slower.
> For
> high schoolers+ I add that the resource has to be reduced to  short
> supply
> due to the joint use by the two competitors and that this has to have
> an
> impact on frequency or efficiency of resource use as measured,
> ultimately,
> by reproductive success.  Finally direct competition is more likely to
> result in evolutionary avoidance of competition by character
> displacement.
> 
> 1.  The clearest real world example is competition for rodent and shrew
> prey
> by diurnal hawks and nocturnal owls in the same habitat.  The prey is
> the
> same but there is rarely if ever contact between the predators.
> 
> 2.  As a model for relative efficiency of use I use plant competition,
> at
> the root level, for water and nutrients.  A suggestion that it is
> important
> can be seen in our deserts with even spacing of shrubs, especially
> creosote
> bush (the roots contact below ground).  As a model I use kids drinking
> soda
> or even water from a cup using a fine bore vs. large bore tygon tube.
> To
> show the difference in efficiency I have the other students measure the
> rate
> of water decline in a separate graduated cylinders with the two
> students.
> Of course you can switch students to control for individual sucking
> abilities.
> 
> I hope this helps.  I have other examples / exercises, for direct
> competition if you are interested.
> 
> Take care, Tom
> 
> Dr. Thomas L. Poulson
> Emeritus Professor in the Ecology and Evolution Group
> Biological Sciences, University of Illinois-Chicago
> 
> tomandliz at bellsouth.net
> 561-630-3643
> 
> 
> On 5/1/07 8:01 AM, "ecoed-request at ecoed.net" <ecoed-request at ecoed.net>
> wrote:
> 
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>> Today's Topics:
>> 
>>    1. competition btw organisms (Kristen Lennon)
>> 
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>> 
> ----------------------------------------------------------------------
>> 
>> Message: 1
>> Date: Mon, 30 Apr 2007 15:25:15 -0400
>> From: "Kristen Lennon" <klennon at aaas.org>
>> Subject: [Ecoed] competition btw organisms
>> To: <ecoed at ecoed.net>
>> Message-ID: <s6360a6a.014 at groupwise.aaas.org>
>> Content-Type: text/plain; charset=US-ASCII
>> 
>> Hi,
>> 
>> I am working on collecting examples of phenomena that I will provide
> to
>> teachers to demonstrate specific ecological concepts to middle
> school
>> students (grades 6-8). Currently, we are talking about competition
>> between organisms for such things as food, water, air, space and
> shelter
>> (including nesting sites). While it is relatively easy to find
> examples
>> of what students will think of as "classic" competition that
> involves
>> direct, interactive competition between organisms (usually with
> visible
>> conflict), we are trying to find examples of competition that do not
>> involve this contact. For example exploitative competition in which
> one
>> organism uses (or exploits) a resource more quickly or efficiently
> than
>> another. This is much harder to find good examples of that can be
> used
>> with children of this age. I would be grateful for any ideas that
> you
>> may have - either examples that I can use or strategies for
> introducing
>> students to this concept.
>> 
>> Thanks again for your help.
>> 
>> Best,
>> Kristen
>> 
>> Kristen A. Lennon, Ph.D.
>> Research Associate
>> Project 2061
>> American Association for the Advancement of Science
>> 1200 New York Ave., NW
>> Washington, DC 20005 USA
>> 
>> 
>> Tel:202-326-7032
>> E-mail: klennon at aaas.org
>> http://project2061.aaas.org
>> 
>> 
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>> End of Ecoed Digest, Vol 37, Issue 1
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