treasures grass

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48 Minnesota Conservation Volunteer

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Page 1: Treasures Grass

48 Minnesota Conservation Volunteer

Page 2: Treasures Grass

By Tom Carpenter

TreasuresGrassin the

Go birding where the grass sways, the horizon sprawls, and these five

prairie songbirds make their home.

Mention birdwatching and many amateur ornithologists envision a woodland hide-and-seek adventure. Warblers flitting through the underbrush. Tanagers flashing through the treetops. Orioles fluttering through the branches.

But there’s another place to observe songbirds—a place where the subjects’ plumage may not be as showy, but where their life stories are right there in the wide open to see. Welcome to the grasslands.

Only 1 percent of Minnesota’s once-vast native prairie remains, but the state has grasslands that still offer habitat for these prairie-loving birds. Where they haven’t been plowed for grain crops, pas-tures—especially those that are rotationally grazed by cattle, as the prairie once was by bison—serve as surrogate habitat for native

CLOCKWISE FROM TOP LEFT: DICKCISSEL BY MICHAEL FURTMAN, GRASSHOPPER SPARROW BY BOB DUNLAP,

SAVANNAH SPARROW BY MICHAEL FURTMAN, PEMBINA TRAIL PRESERVE BY RICHARD HAMILTON SMITH,

BOBOLINK BY MIKE LENTZ, WESTERN MEADOWLARK BY ROLAND JORDAHL

July–August 2018 49

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prairie. So do Conservation Reserve Program and Conservation Reserve Enhancement Program acres, plus other farm bill program acreage that lets land revert back to grass. Waterfowl production areas and wildlife management areas in southern and west-

ern Minnesota offer good grassland songbird habitat. So can fallow fields, forgotten mead-ows, and even hayfields.

For a different kind of birding adventure, explore the big wide open and put the follow-ing five prairie songbirds on your checklist.

Bobolink (Dolichonyx oryzivorus)

A male bobolink in breeding plum-age wears a reverse tuxedo: He is dis-tinctively all-black below but streaked white above, with a creamy-yellow to dull-gold nape. The bill is conical and pointed.

“Male bobolinks are flashy little birds,” says Bob Dunlap, DNR zoologist and grassland bird expert who completed his master’s degree thesis on prairie songbird habitat in western Minnesota. “They show off their napes and ruffle up their neck

feathers when calling.” Bobolinks are a little smaller and slenderer than robins.

A female bobolink is creamy-brown, with a buffy yellow tinge below. She looks a lot like a female red-winged blackbird—and in fact, bobolinks are members of the blackbird family. It’s easy to see the behavioral similarities of a red-winged blackbird clinging to a wetland cattail and a bobolink swaying on a grassland stem.

“In Minnesota, bobolinks were originally birds of the tallgrass prairie,”

50 Minnesota Conservation Volunteer

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says Dunlap. You can find them in prairie remnants, grasslands, and forgotten fields in the Twin Cities metropolitan area and southeastern Minnesota, and meadowlands in central and northeastern Minnesota.

The bobolink song sounds a bit like R2D2 from Star Wars, says Dunlap. It’s a bubbly, happy call that starts with low buzzes and finishes with high-range gurgling.

Bobolinks sometimes key in on alfalfa fields in spring; the cover mimics tallgrass prairie at that time of year. “They will nest in the grass, on the ground, right at the

Western Meadowlark (Sturnella neglecta)

The western meadowlark sings one of the happiest songs in the bird world— a flute-like triplet or so of whistles followed by a gurgly bubble of notes traveling up a musical scale.

“That song is the key to identifying a western meadowlark from the nearly identical eastern meadowlark,” says Dunlap. The eastern sings a mere three-to five-note whistle.

The western meadowlark is robin-sized, about 10 inches long. The sexes are not dimorphic, meaning males and females look alike. In breeding plum-age they are streaked brown on top but bright yellow below, with a prominent black V at the top of the breast.

Meadowlarks are ground feeders. They use long, sharp bills to feed on grains, seeds, and insects, and to probe

July–August 2018

base of grass clumps,” says Dunlap. Bobolinks eat mostly bugs, grubs, and

caterpillars in spring and summer. They are neotropical migrants, wintering in South America and returning to Minnesota when spring warblers do—about the time hard-woods such as oaks and aspens are leafing out and the weather is warm enough for insects to be out and about.

The birds otherwise feed mainly on seeds. They are called “rice birds” in the southern United States because of their penchant for descending on harvested fields in big flocks.

ROLAND JORDAHL

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The eggs of the western meadowlark rest in a nest on the ground.The eggs usually incubate in 13 to 16 days.

and pry the ground for insects and seeds. The western meadowlark is a bird of great-

est conservation need in Minnesota, and

populations have been declining for several decades, says Dunlap, mostly due to conver-sion of native prairie to cropland. At least one recent study also suggests the meadowlark, like many prairie birds, bees, and butterflies, has been affected by neonicotinoids, a group of insecticides used on crops.

“Western meadowlarks range all the way to the eastern edge of Minnesota,” says Dun-lap, “but they seem to be increasingly dif-ficult to find in the eastern part of the state during the breeding season.”

This bird prefers shortgrass prairie habitat and can even be found around airports, with their expanses of mowed grass. But it is also found in tallgrass areas in Minnesota.

“Meadowlarks are blackbirds and ground nesters,” adds Dunlap. The birds often build grass domes over their nest cups. Mead-owlarks love the prairie primeval but adapt well to grassy fields, pastures, meadows, and marshland edges.

Dickcissel (Spiza americana)

If not for its diminutive size—only about 6 inches long—a breeding male dickcissel might be confused for a meadowlark. It features a yellow chest with a black V below the throat, distinc-tive rust-colored shoulder patches, and a yellow eyebrow. Its sturdy, conical bill marks it as a seed eater.

Females show only a little pale yel-low on their chest, though they do display rusty shoulder patches and soft-yellow eyebrows.

“Dickcissels are almost always out in the open and conspicuous,” says Dun-

lap, “where they can get a good view. They perch on road signs, fenceposts, barbed wire, weed and grass stalks, or the occasional prairie tree.”

They’re named after the sound they make, a sharp-to-buzzy dick – dick – dick – ciss-ciss-cis-cis-cis-cis.

Dickcissels are among the last neo-tropical migrants to return to Min-nesota each spring, often not arriving until the last week of May. They spend the winter in South America in huge flocks, eating seeds and grains.

Dickcissels are quite irruptive, mean-

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ing populations can occasionally spike. “Some years there are only a few around, mainly in southwestern Minnesota prairie areas,” says Dunlap. “Other years, dickcissels seem to be everywhere there’s grass. I’ve seen them in parking lots in St. Paul then.” Lightly

grazed pastures, hayfields, and unmowed roadsides all harbor dickcissels too.

“Like many prairie songbirds, dickcissels nest near the bases of grass clumps,” says Dunlap. The young are fed a steady diet of insects before becoming seed eaters.

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Grasshopper Sparrow (Ammodramus savannarum) Sparrows can be challenging to posi-tively identify. “Nearly all sparrows look brown and streaky,” Dunlap says with a laugh. But some “little brown jobs”— such as the grasshopper sparrow—can be thrilling to check off your bird list when you see or hear the right things.

Male and female grasshopper spar-rows are small (only 4 to 5 inches long), with a clear, non-streaked, buffy-colored breast and dark-rufous, scal-loped-looking upper parts. Their crowns sport a cream-colored stripe, and their bills are sharp and pointed. Their un-streaked chest and belly help set them apart from some other prairie sparrows and make a key identification mark.

“Grasshopper sparrows are effi-cient little hunters,” says Dunlap, with grasshoppers, other bugs, and cater-

pillars serving as prey. These sparrows are named not for a food they eat but for the sound they make—a high-pitched trill not unlike that of a sum-mer grasshopper, which rubs a leg on a wing to make noise.

“You have to listen closely,” says Dun-lap. “If you can hear a grasshopper spar-row’s song, you have darn good ears.”

Grasshopper sparrows often prefer shorter-grass habitat—generally, grass that is less than waist-high, and rela-tively sparse.

That makes pastureland prime. When land converts from grazing to grain, grasshopper sparrows suffer, as the spe-cies does better in larger, unfragmented prairies. That has made the grasshop-per sparrow another species of greatest conservation need in Minnesota.

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Page 8: Treasures Grass

Where to Go Prairie Birding

Glacial Ridge National Wildlife Refuge Magnificent, huge, remote. Over 22,000 acres include 5,000 acres of pristine northern tall-grass prairie and 8,000 acres of restored prairie. 14 miles north of Fertile. fws.gov/refuge/glacial_ridge

Buffalo River State Park/Bluestem Prairie Scientific and Natural Area Along with the nearby Moorhead State Univer­sity Regional Science Center, this complex of­fers a large, continuous treasure of undisturbed grasslands: nearly 8,000 acres of native and re­stored prairie. 5 miles east of Glyndon. mndnr.gov/ state_parks; mndnr.gov/snas

Big Stone National Wildlife Refuge This 11,586-acre gem is predominantly restored tallgrass, with more than 1,200 acres of native prairie anchoring the complex. Big Stone hosts nesting waterfowl as well as prairie songbirds. 7 miles southeast of Ortonville. fws.gov/refuge/big_stone

Felton Prairie Scientific and Natural Area This SNA and the adjacent Felton Wildlife Man­agement Area create a patchwork of more than 2,000 acres of prairie, much of it only grazed be­fore and now reverted to its native state. Some of the acreage is dry prairie, a unique habitat. 6 miles east of Felton. mndnr.gov/snas

Wildlife Management Areas Minnesota’s WMAs aren’t just for hunters. Thou­sands of acres’ worth of WMAs in Minnesota’s southern and western counties offer ample grass­land birdwatching opportunities in spring and summer. Find WMAs on the DNR’s Recreation Compass map tool at mndnr.gov/maps/compass. TH

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55July–August 2018