Kelly,

Seems that no one is answering your request so I thought I would take a
stab at it.

Passerines are commonly known as neotropical migrants. A Neotropical
migrant is characterized as a bird which breeds in the Nearctic (North
America) and winters in the Neotropics (South America) but has its
evolutionary origin in the Neotropical zone. Theory has it that these guys
have evolved in the Neotropics and because of competition for food and
habitat etc. in the Neotropics (due to the vast abundance of competitors),
they have moved to the Nearctic range where supplies for food and habitat
is more abundant without so much competition. Examples of birds which have
evolved there and are part of our breeding area include the Ovenbird. The
Neotropical area is not completely unique to those that evolved there
(those that do not come up here to breed). Other examples of birds that
have become successful in the Nearctic area in breeding are birds such as
the new world vultures (Cathartidaea family), wrens, tyrant flycatchers,
blackbirds, and hummers. These guys go back in the winter to there
ancestral place of origin.

The second part of your question relates to what is known as a
"partial-migrant" These birds have the ability to live in the northern
hemisphere through the winters. They only migrate a short distance if at
all. These can be characterized by the American Robins, Mourning Doves,
Crows, etc. If these guys find that there is enough food in the area and
they have sufficient shelter to support their needs through the winter,
they will stay. Its usually the Young and females that like to go south,
the males will stay in these cases; but this is a GENERAL statement, not
always true. Finally, about your question of a list of Neotropical
migrants, well I don't know where one would be able to get a compiled list
like that. Maybe someone else can help you sorry!

I hope that helps you out somewhat?

Cheers!
Libor
----------
> From: Kelly Cassidy <kelly at cqs.washington.edu>
> To: tweeters at u.washington.edu
> Subject: Re: Neotropical migrants
> Date: September 9, 1997 2:15 PM
>
> If anyone has a response to this query about the definition of a
> neotropical migrant, please respond to the list. Is there any
> "official" list of Neotropical migrants?
>
> How about migrants in general? Are robins migrants or residents, since
> part (all?) of the winter population is from the north?
>
> Kelly (one of the "shes") Cassidy