Extinction vs accuracy

[David Webster]

add a few afterthoughts. Note that this is not intended to be an argument-- just an explanation of a point of view.
1) Most literate people cut teeth on accounts of famous extinctions; e.g. great auk, dodo, passenger pigeon.
2) Extinct and extinctions are therefore words in the public domain and "extinct" is strongly associated with irreversible loss of
a species.
3) Being in the public domain, "extinct" is not a technical term, and thus can not be redefined for scientific purposes without
causing confusion.
4) This is not an era of contemplation (even National Geographic wrongly had the millennium start one year too soon and refused to
admit it). It is an era of 5-sec sound clips, 5 word factiods, keyword searches, superficial journalism and hot-button words in
which nearly everything is heard or seen out of context, sometimes with the intent to misinform.
5) It is also an era of proliferating charities, so conservation organizations have to make their causes sound more dire than they
really are in order to get contributions.
6) The entire conservation movement would suffer if even one conservation organization, by accident, inflated species extinction
statistics by including some population extinctions.
Afterthoughts--- To take one example, the range of the Ringlet is expanding and recently reached Nova Scotia. If a contraction of a
range is some kind of extinction, should an expansion be called an unextiction, a disextinction or a creation ? Obviously, none of
the above, it's an expansion. And if that is correct then I wonder why the loss of a species from an island or an outlier station
is more than a decrease in range; often only a symptom of underlying causes.
    Habitat destruction, as Anne says so eloquently, is the loss which counts.
    Dave Webster, Kentville, Nova Scotia
 
 
John Shuey wrote:
 
> I can only go so long with chiming in on this conversation.  Without looking up anything, here is my take (from the perspective
> of a conservation practitioner).  Also note that my grammar sucks in general, so that I may have missed some obvious points
> below.
>
> Extinction - a noun, describes a process that works at several levels - levels which therefore should always be specified when
> using the term.
>
> Extinct - an adjective, describes the status of an entity, such as a population, species, or group of species.
>
> Extirpated, an adjective, similarly describes the status of an entity.  As I know the term, it is always applied to species in
> the context of a definable geographic area. I have never seen this term used to describe single population sites.
>
> So here's how they relate in my mind:
>
>   -    At its most fundamental level, EXTINCTION is a population level process - populations are
>        always at risk of extinction.  But in a functioning ecological landscape, new populations
>        are generally founded at the same rate that populations become extinct, so the net effect is
>        a wash (this would be a stable regional metapopulation).  In today's human dominated
>        landscape, population level extinction often outpaces the founding of new populations.
>
>   -    As localized population extinctions accumulate, a species may become EXTIRPATED
>        from a defined geographic region.  For example, Mitchell's satyr was known historically
>        from a single population in Ohio,  The extinction of that that butterfly from Streetsboro Fen
>        resulted in the extirpation of Mitchell's satyr from Ohio. Karner blues were known
>        from several populations in Ohio, all of which were extinct by the late 1980's  resulting in the
>        extirpation of Karner blues from Ohio (note that it has been re-introduced to Ohio,
>        which doesn't negate the fact of past  population-level extinction nor of past regional
>        extirpation).
>
>    -   As population-level extinctions further accumulate, a species may become EXTINCT - no living
>        individuals survive.  A single population-level extinction resulted in the extinction of a species,
>        the Dodo.  Hundreds, of not thousands of populations of the Wabash Riffelshell Mussel
>        became extinct, ultimately resulting in the extinction of that species.
>
>   -    As groups of species become extinct, the term is often applied to even larger taxonomic
>        groupings.  For example, millions of populations became extinct, resulting in the extinction
>         of hundreds of species, and now all dinosaurs are extinct (except maybe those pesky birds).
>
> If these terms are used properly, (especially relative to the subject of the discussion), they can be very accurate terms with
> little or no ambiguity.
>
>  --
>
> John Shuey
>
>
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