The definition of Neotropic Migrant has been a point of contention
for about 10 years now. At one point almost every bird on the
continent has been identified as a "neotrop" by virtue of the movement
of selected members of a species population. It has even been suggested
that getting one's favorite species identified as a neotrop increased
the potential for grant monies and other kinds of special status
consideration.

I the introduction to _Ecology and Conservation of Neotropical Migrant
Landbirds_ (Hagan & Johnston, ed. 1992) is the following:

"In an attempt to deflect some critism of our use of the term _Neotropical_
migrants, here we operationally define the term as pertaining to those
species that breed in the Nearctic biogeographical realm, but that winter
in the Neotropical realm."

further on:

"We are selectively removing from the definition austral Neotropical migrants,
and altitudinal migrants whose range is entirely restricted to the neotropics."

and even further:

"Having defined the term for our purposes, let us consider the alternatives.
_Nearctic_ migrant is not a sufficient term because it includes many species
that winter no further south than the southern United States....The most
accurate term describing our subject might be _Nearctic-Neotropical_ migrants,
which we viewed as excessively cumbersome.... Because everyone seems to have
a preference, and no single term could please all, we hope readers will
concentrate on the issue at hand."

For me the problem is that any single definition intended to describe
patterns of migration will break down if pushed too far. If we get too
hung up on the definition, we could very well lose sight of the the very
real change in breeding populations of selected species in statistically
significant parts of their ranges. I find it more important to recognise
that Olive-sided Flycatchers appear to be in decline than whether we can
legitimately define them as Neotropical migrants.




--
********************************* I am but mad north-north-west;
* Mike Patterson, Astoria, OR * when the wind is southerly,
* mpatters at orednet.org * I know a hawk from a handsaw.
http://www.pacifier.com/~mpatters -ws