Ornithologists Respond re: Bird die-off in Argentina and West Nile Virus

<x-flowed>Compiled responses from three ornithologists to the question posted
yesterday (re: possibility of connection between bird die off in
Argentina & West Nile Virus):

(1)
From: John_Trapp@fws.gov
Subject: Re: Bird die-off in Argentina, due to Pesticides? West Nile
Virus? Other?

Relatively few North American migratory birds travel as far south as
Argentina; thus, none of the pigeons or any other species in the
family Columbidae, none of the thrushes or any other species in the
family Turdidae, and none of the cardinals or any other species in
the family Cardinalidae of North American origin winter in Argentina.
The reference to the fieldfare (a thrush of the Turdidae family that
breeds in the northern palearctic and winters to north Africa) is
puzzling. It is obviously a reference to some other, totally
different, species.

John L. Trapp
U.S. Fish and Wildlife Service
Division of Migratory Bird Management
Arlington, Virginia USA
(703) 358-1965
john_trapp@fws.gov

(2)
From: "Kevin J. McGowan" <kjm2@cornell.edu>

No, none of these birds is likely to be a North American migrant.
Very few landbirds from here migrate that far south.

Kevin

(3)
From: Ellen Paul <epaul@concentric.net>

We would need more than "cardinals, thrushes" to give a definitive answer.

Fieldfares, are found in England and Europe, except for vagrants that
might make it to North America occasionally. In fact, it is
surprising to read about any number of Fieldfares in Argentina, so I
wonder if
someone is using the common name of Turdus pilaris to describe some
other thrush (since the list also refers to thrushes) or perhaps they
were introduced?

It is unlikely that a large number of birds are recently-arrived
migrants. The pigeons are highly unlikely to be migrants.

The range of Northern Cardinal - Cardinal cardinalis - does not, I
believe, extend below southern Mexico. The Brazilian Cardinal -
Paroaria coronata - is found across northern South America and south
to Uruguay.
Occasional vagrants are found in the Southern U.S.

Migrants from North America to Argentina include several shorebird
species, Swainson's Hawk, Nighthawks, Barn Swallows, Swainson's
Thrush (Catharus ustulatus).

Could a bird with WNV successfully migrate such a long distance? Or
any distance? What would seem more plausible, if WNV has reached
Argentina, is either long-distance transport of infected mosquitos or
mosquito
larva via ship or plane (perhaps in cargo), the arrival of the
disease via an infected human (bit by a mosquito in Argentina) or the
spread from North America to birds in Mexico and south, both through
contact among resident species with overlapping or adjacent ranges or
perhaps through migratory birds. But jumping to Argentina, without an
intermediate geographical distribution, seems unlikely.

Ellen Paul
Executive Director
The Ornithological Council
Mailto:epaul@concentric.net
Ornithological Council Website: http://www.nmnh.si.edu/BIRDNET
"Providing Scientific Information about Birds"

---
Jan 13, 2003 posting:
This posting is forwarded from ProMED mail (id: 20030110.0086).  Both
listservs are eager to hear from ornithologists, with insights and
additional information. Send to <promed@promedmail.org> and
<WESTNILEVIRUS-L@cornell.edu>:
BIRD DIE-OFF - ARGENTINA (BUENOS AIRES)
Date:10 Jan 2003
From: Pablo Nart <p.nart@virgin.net>
Source: Telam 9 Jan 2003 [in Spanish, translated & edited by Mod.JW]
<http://www.telam.com.ar/central_sin13720030109.htm>
Approximately 100 birds have died [suddenly] in the last few days in
the streets of Bartolome Bavio, part of  Magdalena, Buenos Aires
[Province], including pigeons, thrushes, cardinals,and fieldfares. It
is suspected that they died from eating pesticide-contaminated food.
[ProMED-mail moderator's comments: Rodenticide is often spread on
corn, and pigeons will eat the bait,while
insectivorous birds may eat insects dying from insecticide poisoning.
But in these days when we are on the lookout for the arrival of West
Nile virus in South America, it would be important to exclude that
diagnosis.  Perhaps an ornithologist reader can tell us whether any
of the species mentioned are likely to be recently arrived migrants
from North America.  We would like to receive more details of this
outbreak. - Mod.JW]
--
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