• Field Notes
• Grassland Bird Habitat
Grassland Birds and the Habitat They Love
Fall 2004 Newsletter
Our Jewel in the Crown
Just off Hwy. 84 south of Hanover, the Lost Mound Refuge is a 9,500
acre grassland of national significance.
Once the former Savanna Army Depot, now formally known as the
Lost Mound Unit of the Upper Mississippi River National Fish and
Wildlife Refuge, Lost Mound offers a nearly complete grassland bird
Although it also contains an industrial area, abandoned buildings,
and railroad tracks, Lost Mound still harbors a dizzying diversity
of bird species not seen elsewhere in Jo Daviess County.
Close to 100 species of birds depend on the grasslands at Lost
Mound during some portion of their life cycle. Some birds —
such as grasshopper sparrows and western meadowlarks — are
there in abundance.
Others — such as the northern harrier, short-eared owl,
loggerhead shrike, and blue grosbeak — can be counted on the
fingers of both hands.
The resident ornithologist, (Dr. Dan Wenny of the Illinois Natural
History Survey) makes new discoveries daily and is adding to the
bird list at Lost Mound.
His ongoing research is designed to help develop management plans
in partnership with local, state, and national agencies for these
precious but neglected acres.
The Natural Area Guardians have provide volunteers to help with
various projects at Lost Mound and regularly schedule outings and
field trips to sample the diverse flora and fauna there.
To volunteer, contact Chuck Wemstrom and watch our calendars.
We strongly encourage you to participate in one of these activities
at Lost Mound, our Jewel in the Crown.
You are out walking down a country lane between fields of grass
and up pops a little brown bird, clinging to a grass stalk.
You grab your binoculars for a better look and note that the bird
has a conical bill, brown and buff streaking over most of its body,
and a longish tail. Whoops, it’s gone before you could check
for further markings.
Still, you whip out your field guide, confident that you’ll
be able to identify the bird. But, oh, no! There must be dozens of
birds pictured in the guide that fit your description. Does this sound
familiar? Welcome to the world of grassland birds.
In this part of Illinois there are at least eight sparrows that
would fit the above description and another three or four that pass
through on migration in the Spring and Fall. But sparrows are not
the only birds dependent upon grassland habitat.
Depending on your location, while you’re on your stroll, you
might luck into several of the 40 species that require grasslands
during their breeding cycle — birds such as the northern harrier,
sedge wren, dickcissel, bobolink, and the eastern meadowlark.
If you are lucky enough to participate in a birding field trip at
the Lost Mound Refuge (the former Savanna Army Depot) you might see
an upland sandpiper, a loggerhead shrike, a northern mockingbird,
or rarest of all for our area, a blue grosbeak.
Why do Grasslands Matter So Much?
Grasslands can be defined broadly to include all remnant prairies,
prairie restorations, hayfields, agricultural fields, fallow fields,
old fields, pastures, and set-aside (CRP) fields.
There are sedge meadows (damp), savannas (grasslands with a sprinkling
of trees), and barrens (grasslands with shrubby growth). Some of these
habitats are on the dry side, some more woody, but all include at
least some elements of grassland vegetation structure — native
or non-native grasses and forbs (flowering plants).
Grassland birds use these grassland habitats during the breeding
season for courtship, nesting, foraging, rearing young, and roosting
Of the 40 species that depend on grasslands during their breeding
cycle, at least 17 are considered ‘obligate’ species —
that is, birds that require relatively treeless areas for most or
all parts of their breeding cycles, including nesting and foraging.
Although these obligate species may use non-grasslands habitats,
they do not require them for their survival. Some obligate species
are the yellow rail, the short-eared owl, the horned lark, and sparrows
such as the vesper, grasshopper, and Henslow’s sparrow.
Additionally, there are 16 species that commonly occur in grasslands
— birds such as the mallard, killdeer, common nighthawk, red-headed
woodpecker, eastern kingbird, common yellowthroat, and orchard oriole.
Of course, many other birds can also be found foraging in grasslands.
In fact, at least 49 species regularly occur in more open habitat
in our area.
When you consider that over a third of the birds that regularly
inhabit our corner of the state are dependent upon grasslands at some
stage of their lifecycle, it is easy to see why preserving open space
is so vital to their well-being.
We are hearing a lot these days about how vanishing species are
tied to vanishing habitat. What is it about grasslands that make them
so valuable to certain birds during their breeding cycle as well as
At the top of the list are the obvious things that all birds require:
- Food (plants and the seeds they provide as well as the insects
attracted to the plants)
- Shelter from the elements
- Cover from predators.
It’s less well known that each grassland species seems to have
a specific requirement for vegetation height and density. For instance,
grasshopper sparrows, dickcissels, and western and eastern meadowlarks
seem to prefer grasslands with a minimum of shrubs, while field sparrows,
lark sparrows, and orchard orioles thrive where a sprinkling of trees
and shrubs are present. Vesper sparrows search out dry locations with
little ground litter and sparser grasses, while red-winged blackbirds,
bobolinks, and common yellowthroats like taller and thicker vegetation.
How Can We Maintain Grassland Habitat?
Clearly, it takes varied habitat to ensure a variety of species.
Yet it is difficult, if not impossible, to provide all of the variables
needed by a healthy grassland bird community in the few paltry acres
left as large grassland tracts disappear under asphalt, cement, or
Further, many of the remaining open acres are undergoing dramatic
changes. One reason is the change in farming practices. Hay fields
are mowed earlier and more frequently. There is less grassland due
to the shift from mixed agriculture (livestock operations and hayfields)
to intensive row crop farming.
In addition, grassland fragmentation leads to the creation of edges
which promote higher rates of nest predation and nest parasitism.
Fire suppression encourages the growth of woody vegetation, choking
out grasses and forbs. And intensive grazing deprives birds of food
What can individuals do about all of this?
If you are the owner of farm acres, avoid the fragmentation of existing
grassland areas. Don’t hay before mid-July. Educate yourself
through Illinois grassland bird management guidelines available on
the internet, at State agencies, and in bookstores.
Small landowners can make a difference too. Even if you own less
than 50 acres, consider establishing a prairie restoration on a portion
of your land. Though it may not seem that one small prairie plot can
help much, consider the impact of a patchwork of restorations over
a wide area!
Above all, quit mowing so much! Mowing just supports our dependence
on fossil fuels and encourages European starlings to set up housekeeping.