Duck Decline Blamed on Fragmented Habitat

  • A mallard duck hen sitting on her eggs in a strip mall tree planter in Ann Arbor, Michigan. Ducks Unlimited researchers have found that recent declines in duck populations are partly due to a lack of corridors between grasslands where ducks nest and wetlands where they thrive. (Photo by Rebecca Williams)

Researchers with the hunters’ conservation group Ducks Unlimited are reporting they’ve found some of the reasons the duck reproduction rate is falling in the Great Lakes region. The Great Lakes Radio Consortium’s Lester Graham reports:


Researchers with the hunters’ conservation group Ducks Unlimited are reporting they’ve
found some of the reasons the duck reproduction rate is falling. The Great Lakes Radio
Consortium’s Lester Graham reports:

(sound of birds, a duck quacking and a truck door slamming)

YERKES: “Load in.”

Two years ago, we went out in the field with biologist Tina Yerkes and other Ducks
Unlimited researchers.

YERKES: “Every day these guys go out and they track the birds and that’s basically how
we figure out what they’re doing. ”

(sound of newly hatched ducklings peeping with hen hissing)

At the time, they were tracking mallard hens, watching them nest, and watching them as
they moved their ducklings from the nests in the grass to nearby wetlands and lakes.
After three years of study, they found some of the reasons duck reproduction rates are
down. We recently had a chance to sit down and talk with Tina Yerkes about the study.
She says, surprisingly, they found that egg production and nesting are good, despite nests
being destroyed by mowers and predators eating the eggs.

TY: “The problem is duckling survival. We have very poor duckling survival in this
area. And, that leads us to believe that we need to alter habitat programs to actually start
doing more wetlands work.”

LG: “So, what’s happening is the ducks are able to nest, they’re able to hatch out the
ducklings, but then when they move from the grasslands where the nesting is to the
wetlands where the ducks feed, they grow, they’re not surviving. What’s killing them?”

TY: “What we’re seeing is that hens, once they hatch their young, they move right after
the first day into the first wetland and it’s a dangerous journey. Basically, because our
habitat is so fragmented that they’re moving these ducklings through non-grassed areas,
across parking lots, roads. It’s dangerous. And, a lot of the ducklings either die from
exhaustion or predators kill them on the way. A lot of avian predators get them at that

LG: “So, we’re talking about hawks and not so much domestic animals like cats and

TY: “Ah, cats are a problem, yeah. It’s hard to document exactly what is getting them,
but feral cats and domestic cats are a problem. Hawks and jays, sometimes…”

LG: “Blue jays?”

TY: “Blue jays can be mean, yeah. But, it’s interesting to note that if you put those
corridors back between nesting sites and wetlands, it’ll be a much safer journey for

LG: “So, what are you proposing?”

TY: “I would look more away from urban areas where those infrastructures are already
intact. We would not certainly expect anybody to tear that type of stuff up. But, outside
the cities and urban areas there are lots of opportunities to look at areas where there is
grass existing or wetlands existing and then piece the habitat back together where we

LG: “There are places, for instance in Chicago, where they’re working to do exactly that.
Do you see that kind of effort in most of the states you studied?”

TY: “Yes, actually we do. Some states like – Chicago’s a very good example. A very
strong park system not only throughout the city, but out in the suburbs as well and we do
see that in a lot of different places. That’s a positive thing.”

LG: “Where are the worst places for duckling survival?”

TY: “The worst duckling survival was the site that you were at two years ago in Port
Clinton, Ohio. And, if you think about what that habitat looks like, what you have is a
few patches of grass and an area that’s heavily agriculturally based, but all the wetlands
have been ditched and drained so that when a bird has to move from an area where it
nested to get to a nice, safe wetland habitat, they have to make a substantial move across
a lot of open fields that don’t have a lot of cover on them. So, here you’re looking at
maybe piecing cover back between the wetland areas and still being able to maintain farm
operations at the same time.”

LG: “What can farmers do to help duck survival?”

TY: “Oh, let’s see. Leave some patches of grass along the fields, especially if they have
wetlands in their fields. Leave a nice margin around the wetland, a nice vegetative
margin around the wetland because the ducks will nest right in that edge as well. Then
they don’t have to move very far to take the ducklings to a nice food source and a nice

LG: “Now, this is not just about making sure that mallard ducks reproduce. What’s this
going to mean for the ecosystem as a whole?”

TY: “Every time we replace a wetland or replace grass on the landscape, we’re
improving the water quality because those types of habitats remove nutrients and
sedimentation from runoff. So, there’s all kinds of benefits. There are benefits to any
other species that depends on grasslands to nest in or wetlands to either nest in or even
for migratory birds. So there’s just a suite of benefits beyond ducks.”

Tina Yerkes is a biologist with Ducks Unlimited. She says the group will be working
with states to develop programs to encourage development of corridors between the
grasslands where the ducks nest and the wetlands where they thrive.

For the Great Lakes Radio Consortium, I’m Lester Graham.

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