I am on the hunt. I turn my head first one way, then the other, listening closely and trying to hear over the loud rustling of the grasses. Is that raspy little buzz just your ordinary grasshopper? Or is it what I am searching for—a bird?
I catch a flash of brown and snap my binoculars up to my eyes. Too slow.
The bird—if it was a bird—is no longer in that patch of bluestem. So I wait for another glimpse or another buzz that will give me a clue where the mystery creature has gone.
There! I see the bird atop a small bush. Its head tilts back, its beak opens wide, and an underwhelming rasp emerges from the nondescript wad of brown feathers. This is the grasshopper sparrow (Ammodramus savannarum). It's at home here on Red Rock Prairie, a 600-acre preserve of The Nature Conservancy in southwestern Minnesota.
A Conservation Vision
for Upland Habitat
I first envisioned this research project over 10 years ago. I saw the grasshopper sparrow's decline as an early warning. The upland habitats this and other grassland species apparently need to survive and thrive were diminishing as well, yet those lands were not always receiving the necessary protection. Those grass-covered uplands are also important for watershed health. All signs indicated that we needed to prevent conservation train wrecks through targeted action based on the best available science.
We jokingly referred to this project as "Team Lisa," since graduate student Lisa Elliott and I share the same first name, but many people worked to make this happen. Persistence, collaboration with the University of Minnesota, and funding via the USFWS State Wildlife Grant and DNR Nongame Wildlife programs helped our grasshopper sparrow research to take flight.
The project is a springboard, providing valuable baseline information to help guide future research, monitoring, and conservation on both public and private lands. The grasshopper sparrow has been selected for the USFWS surrogate species initiative. By more clearly identifying priority areas, key habitats, and actions, the project enables land managers to make wise use of conservation funds to help reverse declines for grasshopper sparrows. Our findings are contributing to a revision of Minnesota's State Wildlife Action Plan. Eventually, we hope to incorporate grasshopper sparrow conservation into private-lands habitat incentives, state prairie projects, comprehensive watershed conservation, and other landscape-level efforts.
Integrated conservation work is necessary to ensure healthy, diverse ecosystems. In the end, that benefits people too.
Let's face it: The grasshopper sparrow is not the most charismatic bird in the grassland. It is not graced with the melodious, far-carrying song of the meadowlark. Its call is almost indistinguishable from the chirping of a grasshopper. It lacks the eye-catching coloration and attention-grabbing antics of the bobolink. Indeed, the grasshopper sparrow is a rather dull-looking bird in comparison, with brown and taupe coloration alleviated only by dots of yellow just above its eyes. It usually keeps a low profile, skulking down in vegetation. Most birders dismiss the grasshopper sparrow as a "little brown job." Yes, all in all, this bird is an unlikely hero.
Yet, in the course of my fieldwork with the Department of Natural Resources, I have found myself slowly won over by the charms of this humble bird. Every time I see one singing, I have to smile. The way it throws its head back and opens its beak wide reminds me of a Muppet singing at the top of her lungs. You would think the bird was about to sing an aria, not produce a wispy buzz. Every time I hear a grasshopper sparrow, or I am lucky enough to see one, I feel like I've been let in on a secret. Another person, walking along this same transect, would probably overlook this bird. Because of this familiarity, I've mentally claimed these little birds as my own.
Not only are grasshopper sparrows entertaining, but they are also characteristic of a whole suite of unassuming grassland species. These other species are also cryptic creatures, often overlooked. Their ranks include other birds, small mammals (mostly rodents), reptiles, and insects that are all part of an interdependent ecosystem. Like the grasshopper sparrow, many of these species are dwindling in numbers as grasslands are converted to agriculture, fragmented, and degraded.
So what are land managers doing to try to protect grassland habitat and prevent grassland birds from fading into oblivion? Well, the first step is to identify areas where things are going well, or at least better. That is where my research comes in. I am studying where the grasshopper sparrow lives in Minnesota, and I'm trying to understand why it lives in those places. If I can figure out what is different about the conditions and management practices at those sites, that information could help land managers adapt their practices to conserve grassland species.
The decline of grassland birds has been recorded since the 1960s, when the U.S. Geological Survey and the Canadian Wildlife Service first combined forces to monitor bird populations through their annual North American Breeding Bird Survey. The data collected by volunteer citizen scientists suggests that declines of grassland birds are more severe than declines of most other groups of birds. Some species' population dips have been on the public's radar. However, it's hard to notice the disappearance of something you never realized was there. This is the case for many grassland species, including the grasshopper sparrow.
Minnesota's population of grasshopper sparrows is declining by roughly 7 percent each year. The main reason is the sheer loss of temperate grasslands. Minnesota's grasslands no longer stretch from horizon to horizon. Less than one-tenth of 1 percent of the state's original prairie remains. The drop in population numbers for wildlife and plants has intensified as grasslands set aside through the federal Conservation Reserve Program have been converted to cropland. As contracts expire, high prices for corn and soybeans have provided an economic incentive for landowners to plow their land rather than re-enroll it through conservation easements. Consequently, the current high rate of agricultural conversion is comparable to that of the early 20th century when mechanization first occurred.
Fragmentation of habitat is another factor. Trees, buildings, power lines, and wind turbines interrupt the otherwise horizontal expanses of grassland. These vertical structures pose challenges to the health of bird communities because they provide raptors with handy perches from which to hunt grassland residents. Trees also provide habitat for other predators including skunks, raccoons, foxes, and snakes. Grassland songbirds living near any of these structures are more likely to be eaten or to have their nests discovered and destroyed. Some may actively avoid vertical structures.
Much of grassland conservation has focused on protecting habitat for waterfowl. While this is certainly an important goal, their habitat preferences differ. Most prairie waterfowl like areas with wetlands for foraging and tall, dense vegetation for nesting. Grasshopper sparrows and many other species prefer the shorter, sparser vegetation of dry upland prairie. Consequently, when these uplands are overlooked, the inhabitants aren't adequately protected.
To figure out where grasshopper sparrows live, I selected grassland habitats covering a range of conditions and visited as many sites as possible during the breeding season. At each site, I looked and listened for grasshopper sparrows and other birds. Then, once I knew what lived there, I learned as much as possible about the site. I took habitat measurements: How dense and how tall is the vegetation? I also collected information on the surrounding landscape: How far away are the nearest trees? I contacted the site managers to ask questions: Is it native sod, or has it been restored? When was the site last burned, mowed, or grazed? Has tree removal been done?
Now I'm using all of this information to shed light on why different sites have different bird communities.
My research project is part of a larger effort by natural resource agencies to implement a surrogate species approach to ecosystem management. This approach assumes that a subset of species will function as a yardstick for the success of management activities. By addressing the needs of representative species, land managers can improve conditions for many other species. Focusing management efforts on fewer species greatly reduces the time and cost of monitoring multiple species and provides concrete goals for managers.
The grasshopper sparrow is considered a surrogate species because it's characteristic of the underprotected dry upland prairie. Conservation for this species could benefit others. Furthermore, the Minnesota State Wildlife Action Plan, prepared by the DNR, has identified the grasshopper sparrow as a species in greatest conservation need, because it lacks adequate protection, faces growing challenges, and is in decline.
Although we're worried about the future of this species, its numbers are still high enough that we can regularly find it on Minnesota prairies. The presence of grasshopper sparrows is one hallmark of a good surrogate species. Surrogates need to be common enough for researchers to reliably monitor populations and to detect differences in abundance related to differences in site conditions. This isn't possible if a species rarely shows up in surveys, as is increasingly true for western meadowlarks.
Conservation means not just protecting rare species, but also keeping more common species common for healthy, functioning systems. Conservation means protecting not only showy species but also humble ones. This endeavor is why every time I see a grasshopper sparrow singing on a bush, I get excited about my work in the field of conservation.