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Grassland Birds and the Habitat They Love

Fall 2004 Newsletter

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 or resting.
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 on migration?

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 the plow.

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 and shelter.

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.