Maybe we shouldn't give up just yet, as it's important to know to what
extent local nesters may depend on neo-tropical habitats. The world is
never as neat as we might like. How about some arbitrary percentage of
the wintering range (and thus by implication the wintering population...
a shaky extrapolation, I know) lying south of the tropic of cancer?

Gene Hunn.

On Mon, 13 Feb 1995, Michael Smith wrote:

> On Mon, 13 Feb 1995, Priscilla Stanford wrote:
> >
> > Can anyone tell me if there is some sort of official list of neotropical
> > migrants for the Pacific northwest?
>
> Hi Priscilla. This a point of contention between many groups, though one
> which is never really 'figured out'. There are several lists to choose
> from, but you sort of answered your own question further down (I'll get
> back to that in a minute). Anyway, if you really need a list of
> Cascadian (how's that for GC - geographically correct?) migrants, the
> people who worry about it the most are the Northwest Working Group for
> Partners in Flight, who have come up with one. I'd e-mail it to you, but
> I don't have it stored electronically. If you'd like, I'll snail-mail
> one to you. That said, let's get on with part II...
>
> > Also, how far south does a bird have
> > to migrate to be considered a neotropical migrant?
>
> This is the REAL question, which leads me (and many others) to think that
> the whole idea of trying to create a list of so-called neotropical
> migrants is a silly endeavor. What the heck is one? In the east, there
> are many birds which fly across the Gulf of Mexico. That is where the
> term originated, but I also think that's where it should end. Call them
> Trans-Gulf migrants if you must. Of course this ignores the millions of
> little guys who leave from Bay of Fundy, Cape Ann, Cape Cod, Cape May,
> Cape Hatteras, etc, and never see the Gulf of Mexico except out of the
> corner of one eye at the southern terminus of their flight. In the west,
> there is no clear-cut ecological barrier such as the Gulf for birds to
> evolve migrations around. Some (e.g. Bobolink) fly tremendous distances
> during migration, while others will winter in Arizona, Texas, California,
> Mexico, or much closer to home. You see the problem? Trying to create a
> category of birds based on their migration ends up being a very biased and
> very arbitrary decision. Do you count a species if one individual crosses
> the Tropic, or goes into Mexico, or beyond? Or must it be all individuals
> in a species, population, ... It could go on and on. Trying to
> categorize species as 'neotropical' or not will ultimately fail, because
> migrations are not that simplistic and represent a continuum of
> evolutionary adaptations, not one of 2 categories.
>
> ____________________________
> Mike Smith
> Univ. of Washington, Seattle
> whimbrel at u.washington.edu
> http://salmo.cqs.washington.edu/~wagap/mike.html
>
>
>