the wetland changes. This natural
cycle can take five to 10 years. In a
natural setting ducks would utilize
different stages of this natural cycle
depending on whether the birds are
nesting, migrating, or overwintering.
Human interference has changed the
natural landscape, and managers need
to consider not only what’s happen-
ing on their property but on the sur-
rounding land.
“You need to consider your wet-
land in the context of everything else
around it,” Davis says. For example,
if your neighboring properties are
all cattail marshes then you might
be best-served using moist soil man-
agement techniques. In areas where
agricultural crops provide the bulk of
the birds’ diet a property with diverse
native plants and invertebrates pro-
vides critical food sources that will
draw birds.
“Clearly you don’t have control
over other wetlands,” Davis says.
“But it’s worthwhile to talk to your
neighbors and state agencies and try
to develop a plan.” Dr. Davis warns
against getting in the rut of drawing
down and planting at the same time
each year. Identical drawdown and
planting techniques work, but they
don’t mimic the wetland’s natural
wet/dry cycle. And if you are on the
same planting routine as your neigh-
bors you really haven’t done anything
that will make your property more
attractive than theirs. Diverse wet-
land habitats in different life stages (a
wet soil managed impoundment, a
mature cattail slough, an upland nest-
ing area) on your property improve
the overall health of the ecosystem—
and they attract more birds.HEMI-MARSH MODEL
If you’re a waterfowl manager you
should know the name Milt Wells.
While serving as a professor at Iowa
State University, Dr. Wells studied
wetland habitats in the mid-20th
century. During the 1950s, Wells
watched as a drought in the Midwest
dried marshlands and greatly reduced
the number of bird species present.
As normal water levels returned
in those areas, muskrats began cut-
ting vegetation and soon the same
wetland areas that were bone dry
and barren were covered by an equalmix of vegetation and surface water.
It was during that period of propor-
tionally equal plant cover and open
water that productivity and bird pop-
ulations increased. Years later heavy
rains increased water levels so that
the same area was devoid of surface
plants, and biodiversity dropped.
So what’s that have to do with pri-
vate land waterfowl management?
A lot, actually. Wells observed that
when wetlands were a 50/50 mix of
vegetation and open water biodiver-
sity spiked, and that brought in more
ducks. What Wells witnessed in Iowa
forever changed waterfowl manage-
ment. Wells referred to wetlands
with a mix of standing vegetation
and water as hemi-marshes. And, as
it turns out, hemi-marshes make great
duck habitat.
“The diversity of hemi-marsh habi-
tats provides food and nesting areas
for ducks,” Dr. Davis says. In particu-
lar, hemi-marshes promote inverte-
brates, and invertebrates are critically
important for waterfowl health.
“Invertebrates provide crucial
protein to hens and ducklings,” Dr.
Davis says. Those invertebrates,34 WILDFOWL Magazine | September 2019 wildfowlmag.com
©Kenny Bahr