[mou] Trumpeter Swan buildup danger

[Robert_Russell at fws.gov]

My personal belief and whispered talk around my agency is that this
artificially-induced buildup of Trumpeter Swans at Monticello is a disaster
waiting to happen.  Such huge buildups of swans are way beyond the natural
concentrations of swans in most areas of its natural range.  The potential
for a disease such as botulism to wipe out a large portion of a wintering
flock has been documented in Idaho a couple of decades ago when several
hundred swans died.  Swans are also subject to other diseases (cholera,
avian tuberculosis, various forms of avian flu) which spread faster and
with more devastation in crowded surroundings.  My big fear is that the
trematodes that killed  6,000-7,000 scaup (both species) and 200 coots
(different trematode) on the Upper Mississippi at Lake Winnibigoshis and
killed 22,000 to 26,000 (!!) lesser scaup and coots in spring 2006 in the
LaCrosse area will spread north or south and affect the wintering grounds
at Monticello.  The trematodes near LaCrosse are associated with the exotic
faucet snail (from Europe I believe) while an exotic snail at Lake Winnie
(introduced from eastern USA) may be to blame for the waterfowl deaths
there.  While snails may not be a primary forage item for snails, ingestion
seems inevitable in the shallow waters of the Mississippi as does the
spread of these snails and associated trematodes all along the Mississippi
River.  Before we have a major disaster at this site which could set back
swan restoration in the Midwest back a decade or more, someone needs to act
to encourage these birds to migrate farther south, like maybe prohibiting
feeding when the birds first show up in the fall.  Trumpeter Swan Society
are you listening?  Bob Russell, US Fish and Wildlife Service
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