of west-central Missouri, Chuck Geier knows when temperatures will drop
and waters will freeze. That means he also knows when the birds will
fly and hunting will be best.
Except that now much of what he knows is in question.
“It used to be by Dec. 6, this place was frozen,” said Mr. Geier, 51, a
national sales manager for a telecommunications company. “That’s not
From the “prairie potholes” of Canada and the Upper Midwest to the
destination states of Arkansas and Louisiana, the rhythms of the
cross-continental migratory bird route known as the Mississippi Flyway
Here in Missouri, where the five-year winter temperature average has
been on a striking ascent, hunters say birds are arriving later and
sticking around longer before bolting for warmer redoubts. Elsewhere,
wetlands are not freezing over the way they once did.
As hunters point their shotguns toward the sky and fire, a question
echoes in the spent powder: what, please, is up with the ducks?
“People say it’s cycles, every five to seven years, but it’s just been
too long,” said Mr. Geier of the warming trend, which he traces to the
late 1990s. “It’s a wake up call.”
Five-year averages for “duck use” days on some conservation areas in
Missouri show peaks that come a week or more later in the year than do
the 30-year averages. Hunters have said in state surveys that they want
later hunting seasons, reflecting the later arrival of major weather
systems that move birds into the state.
The Mississippi Flyway is one of four main migratory bird routes that
bisect the country, and hunters in some other regions of the country
have also reported shifts in duck behavior.
“We’re having milder falls, later winters,” said Dave Erickson, chief
of the wildlife division for the Missouri Department of Conservation.
“What we don’t know is if the trend that affects migration and the
hunters’ desire for a longer hunting season is a temporary fixture or a
Sure science is elusive. Scientists and state wildlife officials say
there is no clear-cut data to support the reports of changes in duck
behavior, but the patterns are familiar. They note that various other
animal species, from songbirds to frogs and foxes, are developing
different breeding and migration patterns.
“We’re seeing northern range shifts of lots of birds and butterflies,”
said Dr. Camille Parmesan, a professor of conservation biology at the
University of Texas and a member of the United Nations panel recently
awarded the Nobel Prize for its work documenting climate change.